VintageBigBlue.org

 

Re: [Losmandy_users] Looking for example G11 PEC file for pempro testing


Jan 1, 2001

 


----------------------------

#1768 Jan 1, 2001

On the WWW and newsgroups there is much anecdotal evidence

and some empirical evidence of variable/poor periodic error

performance of the G11 mount. Having bought 3-4 year old

example, I decided to use the CCD guidance logging facility

of Maxim DL to see what my PE looked like.



Celestron Losmandy G11 (recently lubed)

TV101 refractor

Starlight Xpress MX5c colour camera

Maxim DL CCD control software



The log file was imported into Excel, converted from pixels

of error to arc seconds of error, and results for a 4-minute

worm rotation are shown graphically at



www.strachan-stephens.freeserve.co.uk/PE.htm



The software captured a data point every 2 or 3 seconds.



My subjective views of the results are: -



PE of approx +/- 7 arc seconds is pretty good



Generally reasonably smooth curves, however the corner

points are quite sharp and I wonder whether a guider would

follow these well



Not the same high amounts of noise in the system as some

have found. What noise there is is usually of the order of

1 arc sec or less from data point to data point.



Obvious evidence of polar axis misalignment causing the dec

drift. This has the potential of being turned into a tool

for very accurate polar alignment



Some (purely visual) very slight evidence of cross-talk

between the axes. The dec is almost looking like the

derivative of the RA.



In conclusion, I think my mount is best left well alone with

no changes to bearings, worms, worm alignments or anything

else. No need to temp fate is there? Unless someone can

tell me otherwise of course.



I may will do further work on:-



Can a 4 minute snapshot like this give you sufficient

information from the rates of change of both axes and a

knowledge of where in the sky you are pointing to accurately

define where the polar axis is pointing? Certainly the

chart can be used for a fairly accurate conventional drift

alignment.



Is the point to point variation seen in the curves a measure

of seeing in some way?



Any and all comments appreciated



Regards



Adam Stephens



----------------------------

#1769 Jan 1, 2001

Adam,



I agree. As posted before, I have many example of 30 minute or longer

self guided images on my web page that indicate that, other then the

re-lubing process on the bearings, I wouldn't change anything.



Regards,



Steve

www.cstone.net/~sreilly/



Adam Stephens wrote:

> On the WWW and newsgroups there is much anecdotal evidence

> and some empirical evidence of variable/poor periodic error

> performance of the G11 mount. Having bought 3-4 year old

> example, I decided to use the CCD guidance logging facility

> of Maxim DL to see what my PE looked like.

>

> Celestron Losmandy G11 (recently lubed)

> TV101 refractor

> Starlight Xpress MX5c colour camera

> Maxim DL CCD control software

>

> The log file was imported into Excel, converted from pixels

> of error to arc seconds of error, and results for a 4-minute

> worm rotation are shown graphically at

>

> www.strachan-stephens.freeserve.co.uk/PE.htm

>

> The software captured a data point every 2 or 3 seconds.

>

> My subjective views of the results are: -

>

> PE of approx +/- 7 arc seconds is pretty good

>

> Generally reasonably smooth curves, however the corner

> points are quite sharp and I wonder whether a guider would

> follow these well

>

> Not the same high amounts of noise in the system as some

> have found. What noise there is is usually of the order of

> 1 arc sec or less from data point to data point.

>

> Obvious evidence of polar axis misalignment causing the dec

> drift. This has the potential of being turned into a tool

> for very accurate polar alignment

>

> Some (purely visual) very slight evidence of cross-talk

> between the axes. The dec is almost looking like the

> derivative of the RA.

>

> In conclusion, I think my mount is best left well alone with

> no changes to bearings, worms, worm alignments or anything

> else. No need to temp fate is there? Unless someone can

> tell me otherwise of course.

>

> I may will do further work on:-

>

> Can a 4 minute snapshot like this give you sufficient

> information from the rates of change of both axes and a

> knowledge of where in the sky you are pointing to accurately

> define where the polar axis is pointing? Certainly the

> chart can be used for a fairly accurate conventional drift

> alignment.

>

> Is the point to point variation seen in the curves a measure

> of seeing in some way?

>

> Any and all comments appreciated

>

> Regards

>

> Adam Stephens

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com







----------------------------

#1770 Jan 1, 2001

Your results seem interesting and similar to mine, see G11-

noise.pdf in the files section by me. Since I didnt have a capture

routine, I captured the ST-4 data by hand, i.e. recoring every 5

seconds for 12 minutes. (takes more than patience when its cold

outside.) The St-4 was used in the "Find and Focus" mode and

converted to pixels. I could have converted to arcmin but wanted to

keep track of the ST-4 readability. What is different between our

results is that I observed a greater amount of random noise. In

other words about 50% of the variability observed over 12 min was due

to "random noise". I used quotes because an alternative explaination

is that it was due to "Tic-Tic" of the digital motors. If it were

due to the motors, than these would have been to fast for me to

record and would have appeared to be random.





--- In Losmandy_users@egroups.com, Adam Stephens adamstephens@a...>

wrote: > On the WWW and newsgroups there is much anecdotal evidence

> and some empirical evidence of variable/poor periodic error

> performance of the G11 mount. Having bought 3-4 year old

> example, I decided to use the CCD guidance logging facility

> of Maxim DL to see what my PE looked like.

>

> Celestron Losmandy G11 (recently lubed)

> TV101 refractor

> Starlight Xpress MX5c colour camera

> Maxim DL CCD control software

>

> The log file was imported into Excel, converted from pixels

> of error to arc seconds of error, and results for a 4-minute

> worm rotation are shown graphically at

>

> www.strachan-stephens.freeserve.co.uk/PE.htm

>

> The software captured a data point every 2 or 3 seconds.

>

> My subjective views of the results are: -

>

> PE of approx +/- 7 arc seconds is pretty good

>

> Generally reasonably smooth curves, however the corner

> points are quite sharp and I wonder whether a guider would

> follow these well

>

> Not the same high amounts of noise in the system as some

> have found. What noise there is is usually of the order of

> 1 arc sec or less from data point to data point.

>

> Obvious evidence of polar axis misalignment causing the dec

> drift. This has the potential of being turned into a tool

> for very accurate polar alignment

>

> Some (purely visual) very slight evidence of cross-talk

> between the axes. The dec is almost looking like the

> derivative of the RA.

>

> In conclusion, I think my mount is best left well alone with

> no changes to bearings, worms, worm alignments or anything

> else. No need to temp fate is there? Unless someone can

> tell me otherwise of course.

>

> I may will do further work on:-

>

> Can a 4 minute snapshot like this give you sufficient

> information from the rates of change of both axes and a

> knowledge of where in the sky you are pointing to accurately

> define where the polar axis is pointing? Certainly the

> chart can be used for a fairly accurate conventional drift

> alignment.

>

> Is the point to point variation seen in the curves a measure

> of seeing in some way?

>

> Any and all comments appreciated

>

> Regards

>

> Adam Stephens



----------------------------

#1772 Jan 1, 2001

Hi Adam.



I have a few questions and comments.

> The software captured a data point every 2 or 3 seconds.



Is this about the rate at which you usually issue guiding corrections?

Strikes me as perhaps OK for emulsion, but a bit slow for CCD work. Would

you consider sampling at a faster rate of say every.5 second as a reasonable

data gathering technique.

>

> My subjective views of the results are: -

>

> PE of approx +/- 7 arc seconds is pretty good

>



Reasonably close to the smoothed curves I see. I am concerned about the

distance between my data points. Call it noise or what you like, but I see

points next to each other that range several arc apart. I see a dramatic

reduction in this noise when running a microstepped motor. That is counter

to Scott's estimation of the contribution from each piece in the chain.

There is still a significant amount noise present that I have yet to trace

the source of. Bearings, the coupling, and the gears themselves each will

have a component. Trying to assign an amount of noise to each piece will

take some further experimentation. I need an easy way to do this work

indoors.

>

> Not the same high amounts of noise in the system as some

> have found. What noise there is is usually of the order of

> 1 arc sec or less from data point to data point.



I wonder how my numbers would look if I sampled at 2-3 second intervals?

>

> In conclusion, I think my mount is best left well alone with

> no changes to bearings, worms, worm alignments or anything

> else. No need to temp fate is there? Unless someone can

> tell me otherwise of course.

>



Probably best left alone. Some of us just have to measure things and tinker

with the pieces.

>

> Can a 4 minute snapshot like this give you sufficient

> information from the rates of change of both axes and a

> knowledge of where in the sky you are pointing to accurately

> define where the polar axis is pointing? Certainly the

> chart can be used for a fairly accurate conventional drift

> alignment.



Perhaps better to average a couple of worm rotations. Dec drift over time

should be a good measure though.

>

> Is the point to point variation seen in the curves a measure

> of seeing in some way?

>



My thoughts about measuring the seeing come from comparing the scatter on

the Dec axis to that of the Ra. The Dec scatter should be an accurate

measure of the seeing conditions. Subtract that range from the Ra and you

should be looking at the mechanical system noise and error contribution.



My $0.02, Marty



Martin Niemi



www.ameritech.net/users/mniemi000/index.html



Mailto:mniemi000@...







----------------------------

#1773 Jan 1, 2001

Marty wrote:

> > The software captured a data point every 2 or 3 seconds.

>

> Is this about the rate at which you usually issue guiding corrections?

> Strikes me as perhaps OK for emulsion, but a bit slow for CCD

> work. Would you consider sampling at a faster rate of say every.5 second

> as a reasonable data gathering technique.



I have found that guiding a CCD at 2 second exposures is quite satisfactory. I

suspect that when you guide at .5 second intervals you suffer two constraints.

First, the shorter exposure restricts you to brighter guiding stars. Second, a

shorter exposure may mean that you are trying to track the scintillation of the

star, which on a longer exposure averages out.



Greg Crawford



----------------------------

#1774 Jan 1, 2001

Marty

>I have a few questions and comments.

>

>> The software captured a data point every 2 or 3 seconds.

>

>Is this about the rate at which you usually issue guiding corrections?

>Strikes me as perhaps OK for emulsion, but a bit slow for CCD work. Would

>you consider sampling at a faster rate of say every.5 second as a reasonable

>data gathering technique.



Just for clarity, I was not guiding at the time. The

software was simply measuring the deviation of the star from

the moment I told it to start. The 2 or 3 secs simply came

from the download speed of the software. I suspect that if

I tightened the box surrounding the guide star I would get a

finer resolution. I will do this next time and report.

Whether I can get down to 0.5 secs though I do not know.



Generally with my 4 inch refractor I will not find a guide

star bright enough at 0.5 secs guiding. I usually use 1 or

2 secs. I find that when I have used 3+ secs the guiding is

not very good. I would suspect that at very low intervals

0.5- that the guider might be chasing seeing. For me 1 to 2

secs is optimum, but I will go higher if needed.

>

>>

>> My subjective views of the results are: -

>>

>> PE of approx +/- 7 arc seconds is pretty good

>>

>

>Reasonably close to the smoothed curves I see. I am concerned about the

>distance between my data points. Call it noise or what you like, but I see

>points next to each other that range several arc apart. I see a dramatic

>reduction in this noise when running a microstepped motor. That is counter

>to Scott's estimation of the contribution from each piece in the chain.

>There is still a significant amount noise present that I have yet to trace

>the source of. Bearings, the coupling, and the gears themselves each will

>have a component. Trying to assign an amount of noise to each piece will

>take some further experimentation. I need an easy way to do this work

>indoors.



Ditto. Cannot think of one though 8-(



>>

>> In conclusion, I think my mount is best left well alone with

>> no changes to bearings, worms, worm alignments or anything

>> else. No need to temp fate is there? Unless someone can

>> tell me otherwise of course.

>>

>

>Probably best left alone. Some of us just have to measure things and tinker

>with the pieces.



I am desperately trying to stop myself doing this 8-)



>My thoughts about measuring the seeing come from comparing the scatter on

>the Dec axis to that of the Ra. The Dec scatter should be an accurate

>measure of the seeing conditions. Subtract that range from the Ra and you

>should be looking at the mechanical system noise and error contribution.



Yes, good logic.



I'm not a statistician, but I can work a spreadsheet, do you

have a view as to how bet to quantify the scatter range on

one axis and then subtract from the other axis?



Adam



----------------------------

#1780 Jan 2, 2001

Steve Reilly wrote:

> Adam,

>

> I agree. As posted before, I have many example of 30 minute or longer

> self guided images on my web page that indicate that, other then the

> re-lubing process on the bearings, I wouldn't change anything.



I'm new to the G-11 and this group, so I apologize for the intrusion,

but what is the relube process for the bearings. Would I find it in the

archives and could you point me to them?



thx



--jl

>

>

> Regards,

>

> Steve

> www.cstone.net/~sreilly/

>

> Adam Stephens wrote:

>

> > On the WWW and newsgroups there is much anecdotal evidence

> > and some empirical evidence of variable/poor periodic error

> > performance of the G11 mount. Having bought 3-4 year old

> > example, I decided to use the CCD guidance logging facility

> > of Maxim DL to see what my PE looked like.

> >

> > Celestron Losmandy G11 (recently lubed)

> > TV101 refractor

> > Starlight Xpress MX5c colour camera

> > Maxim DL CCD control software

> >

> > The log file was imported into Excel, converted from pixels

> > of error to arc seconds of error, and results for a 4-minute

> > worm rotation are shown graphically at

> >

> > www.strachan-stephens.freeserve.co.uk/PE.htm

> >

> > The software captured a data point every 2 or 3 seconds.

> >

> > My subjective views of the results are: -

> >

> > PE of approx +/- 7 arc seconds is pretty good

> >

> > Generally reasonably smooth curves, however the corner

> > points are quite sharp and I wonder whether a guider would

> > follow these well

> >

> > Not the same high amounts of noise in the system as some

> > have found. What noise there is is usually of the order of

> > 1 arc sec or less from data point to data point.

> >

> > Obvious evidence of polar axis misalignment causing the dec

> > drift. This has the potential of being turned into a tool

> > for very accurate polar alignment

> >

> > Some (purely visual) very slight evidence of cross-talk

> > between the axes. The dec is almost looking like the

> > derivative of the RA.

> >

> > In conclusion, I think my mount is best left well alone with

> > no changes to bearings, worms, worm alignments or anything

> > else. No need to temp fate is there? Unless someone can

> > tell me otherwise of course.

> >

> > I may will do further work on:-

> >

> > Can a 4 minute snapshot like this give you sufficient

> > information from the rates of change of both axes and a

> > knowledge of where in the sky you are pointing to accurately

> > define where the polar axis is pointing? Certainly the

> > chart can be used for a fairly accurate conventional drift

> > alignment.

> >

> > Is the point to point variation seen in the curves a measure

> > of seeing in some way?

> >

> > Any and all comments appreciated

> >

> > Regards

> >

> > Adam Stephens

> >

> > To unsubscribe from this group, send an email to:

> > Losmandy_users-unsubscribe@egroups.com

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com







----------------------------

#1788 Jan 2, 2001

This is most interesting.



I have been following the thread on this and want to graph my guiding.

Currently,I am using an st-7e with ccdops and MaximDL/CCD.

I have a Tracklog file of an imaging session and have tried Maxim/view/line

profile where you see all the guide exposures but I can't figure out what to

do with it.

You can apply horizontal lies,vertical lines etc but can't get the data to

graph.

I have MS Works spreadsheet program but can't figure out how to "dump" the

tracklog into the spreadsheet.



Can anybody help?



Thanks



Jimmy



>From: Adam Stephens adamstephens@...>

>Reply-To: Losmandy_users@egroups.com

>To: Losmandy_users@egroups.com

>Subject: Re: [Losmandy_users] Another G11 PE analysis - Results seem good

>Date: Tue, 02 Jan 2001 06:02:44 +0000

>

>Marty

>

> >I have a few questions and comments.

> >

> >> The software captured a data point every 2 or 3 seconds.

> >

> >Is this about the rate at which you usually issue guiding corrections?

> >Strikes me as perhaps OK for emulsion, but a bit slow for CCD work.

>Would

> >you consider sampling at a faster rate of say every.5 second as a

>reasonable

> >data gathering technique.

>

>Just for clarity, I was not guiding at the time. The

>software was simply measuring the deviation of the star from

>the moment I told it to start. The 2 or 3 secs simply came

>from the download speed of the software. I suspect that if

>I tightened the box surrounding the guide star I would get a

>finer resolution. I will do this next time and report.

>Whether I can get down to 0.5 secs though I do not know.

>

>Generally with my 4 inch refractor I will not find a guide

>star bright enough at 0.5 secs guiding. I usually use 1 or

>2 secs. I find that when I have used 3+ secs the guiding is

>not very good. I would suspect that at very low intervals

>0.5- that the guider might be chasing seeing. For me 1 to 2

>secs is optimum, but I will go higher if needed.

>

> >

> >>

> >> My subjective views of the results are: -

> >>

> >> PE of approx +/- 7 arc seconds is pretty good

> >>

> >

> >Reasonably close to the smoothed curves I see. I am concerned about the

> >distance between my data points. Call it noise or what you like, but I

>see

> >points next to each other that range several arc apart. I see a dramatic

> >reduction in this noise when running a microstepped motor. That is

>counter

> >to Scott's estimation of the contribution from each piece in the chain.

> >There is still a significant amount noise present that I have yet to

>trace

> >the source of. Bearings, the coupling, and the gears themselves each

>will

> >have a component. Trying to assign an amount of noise to each piece will

> >take some further experimentation. I need an easy way to do this work

> >indoors.

>

>Ditto. Cannot think of one though 8-(

>

>

> >>

> >> In conclusion, I think my mount is best left well alone with

> >> no changes to bearings, worms, worm alignments or anything

> >> else. No need to temp fate is there? Unless someone can

> >> tell me otherwise of course.

> >>

> >

> >Probably best left alone. Some of us just have to measure things and

>tinker

> >with the pieces.

>

>I am desperately trying to stop myself doing this 8-)

>

>

> >My thoughts about measuring the seeing come from comparing the scatter on

> >the Dec axis to that of the Ra. The Dec scatter should be an accurate

> >measure of the seeing conditions. Subtract that range from the Ra and

>you

> >should be looking at the mechanical system noise and error contribution.

>

>Yes, good logic.

>

>I'm not a statistician, but I can work a spreadsheet, do you

>have a view as to how bet to quantify the scatter range on

>one axis and then subtract from the other axis?

>

>Adam

>

>

>To unsubscribe from this group, send an email to:

>Losmandy_users-unsubscribe@egroups.com

>

>

>



---------------

Get Your Private, Free E-mail from MSN Hotmail at www.hotmail.com



----------------------------

#1791 Jan 3, 2001

Hi Greg,



If you are just recording, it is easy to determine what the seeing is. The

Dec axis should be a good record of the centroid movement attributable to

the scintillation. During guiding, there is bound to be some coupling of

the Dec to the Ra corrections, but just turn off guiding and record data for

a bit. Paints a pretty clear picture.



I have been thinking long and hard about what the optimal update rate is for

a mechanical system such as a motor driven mount. Obviously you cannot do

what you can with tilt-tip mirror system such as an AO-7. There seems to be

two schools of thought about how the best guiding accuracy is attained. I

would like to explore ways to quantify this instead of instead of restating

the same old arguments.



-Marty



----- Original Message -----

From: "Greg Crawford" gc@...>

To: Losmandy_users@egroups.com>

Sent: Tuesday, January 02, 2001 12:01 AM

Subject: RE: [Losmandy_users] Another G11 PE analysis - Results seem good





> Marty wrote:

>

> > > The software captured a data point every 2 or 3 seconds.

> >

> > Is this about the rate at which you usually issue guiding corrections?

> > Strikes me as perhaps OK for emulsion, but a bit slow for CCD

> > work. Would you consider sampling at a faster rate of say every.5

second

> > as a reasonable data gathering technique.

>

> I have found that guiding a CCD at 2 second exposures is quite

satisfactory. I

> suspect that when you guide at .5 second intervals you suffer two

constraints.

> First, the shorter exposure restricts you to brighter guiding stars.

Second, a

> shorter exposure may mean that you are trying to track the scintillation

of the

> star, which on a longer exposure averages out.

>

> Greg Crawford

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com

>

>

>

>







----------------------------

#1822 Jan 3, 2001

James



If you have a new new mount you should not worry about lube

for at least a year.



There was an issue with the lube solidifying after about a

year. Losmandy say they have recently remedied this by

changing the lubricant. So, I would say that if your mount

is new, check it in about a year, hopefully you will have no

problems



If your new mount is second hand. Rush down to it now and

check if you have solid lubricant. Mine did!



It is an easy job to re-lube there are one or two

descriptions on the web try



members.aol.com/c8g11/g11clean.html



Also try searching the achieves of egroups. There has been

much discussion over the last few months on this subject.



BTW I think the consensus of this group and others is that

the G11 is a fine mount for the money. Most examples work

fine, a minority need to be tuned a little for best

performance. So do not read all the tales of woe here and

convince yourself that you have made a bad choice - you

haven't.



Adam



On Tue, 02 Jan 2001 11:40:03 -0600, you wrote:



>Steve Reilly wrote:

>

>> Adam,

>>

>> I agree. As posted before, I have many example of 30 minute or longer

>> self guided images on my web page that indicate that, other then the

>> re-lubing process on the bearings, I wouldn't change anything.

>

>I'm new to the G-11 and this group, so I apologize for the intrusion,

>but what is the relube process for the bearings. Would I find it in the

>archives and could you point me to them?

>

>thx

>

>--jl

>

>>

>>

>> Regards,

>>

>> Steve

>> www.cstone.net/~sreilly/

>>

>> Adam Stephens wrote:

>>

>> > On the WWW and newsgroups there is much anecdotal evidence

>> > and some empirical evidence of variable/poor periodic error

>> > performance of the G11 mount. Having bought 3-4 year old

>> > example, I decided to use the CCD guidance logging facility

>> > of Maxim DL to see what my PE looked like.

>> >

>> > Celestron Losmandy G11 (recently lubed)

>> > TV101 refractor

>> > Starlight Xpress MX5c colour camera

>> > Maxim DL CCD control software

>> >

>> > The log file was imported into Excel, converted from pixels

>> > of error to arc seconds of error, and results for a 4-minute

>> > worm rotation are shown graphically at

>> >

>> > www.strachan-stephens.freeserve.co.uk/PE.htm

>> >

>> > The software captured a data point every 2 or 3 seconds.

>> >

>> > My subjective views of the results are: -

>> >

>> > PE of approx +/- 7 arc seconds is pretty good

>> >

>> > Generally reasonably smooth curves, however the corner

>> > points are quite sharp and I wonder whether a guider would

>> > follow these well

>> >

>> > Not the same high amounts of noise in the system as some

>> > have found. What noise there is is usually of the order of

>> > 1 arc sec or less from data point to data point.

>> >

>> > Obvious evidence of polar axis misalignment causing the dec

>> > drift. This has the potential of being turned into a tool

>> > for very accurate polar alignment

>> >

>> > Some (purely visual) very slight evidence of cross-talk

>> > between the axes. The dec is almost looking like the

>> > derivative of the RA.

>> >

>> > In conclusion, I think my mount is best left well alone with

>> > no changes to bearings, worms, worm alignments or anything

>> > else. No need to temp fate is there? Unless someone can

>> > tell me otherwise of course.

>> >

>> > I may will do further work on:-

>> >

>> > Can a 4 minute snapshot like this give you sufficient

>> > information from the rates of change of both axes and a

>> > knowledge of where in the sky you are pointing to accurately

>> > define where the polar axis is pointing? Certainly the

>> > chart can be used for a fairly accurate conventional drift

>> > alignment.

>> >

>> > Is the point to point variation seen in the curves a measure

>> > of seeing in some way?

>> >

>> > Any and all comments appreciated

>> >

>> > Regards

>> >

>> > Adam Stephens

>> >

>> > To unsubscribe from this group, send an email to:

>> > Losmandy_users-unsubscribe@egroups.com

>>

>> To unsubscribe from this group, send an email to:

>> Losmandy_users-unsubscribe@egroups.com

>

>

>To unsubscribe from this group, send an email to:

>Losmandy_users-unsubscribe@egroups.com

>

>



----------------------------

#2281 Jan 23, 2001

Posted to

ccd-newastro@egroups.com

Losmandy_users@egroups.com

mx5c@egroups.com





Further to my analysis of a few weeks ago, I was getting

some nights where my G11 PE was good and some when the PE

was bad. So, I have been doing a bit of investigating to

see if I could figure out why.



This post and examples of the graphs I refer to are at:-

www.strachan-stephens.freeserve.co.uk/pe2.htm



Equipment - G11- Mx5c - Star2000 - Maxim DL



Using the guiding function of Maxim DL it is possible to

record the movements of a star in the guiding window. With

some simple use of MS Excel this can be converted into PE in

arc seconds, and a graph made illustrating the movements of

the star in both RA and DEC.



Here is my tentative evaluation of the behaviour of my G11:-



1..I have found that the PE of my (emphasis on my)

mount is very sensitively dependent on how tight the RA

clutch knob is tightened. Up to the point where the RA

clutch was tightened sufficiently to just feel the drag on

the scope, the PE was in the range of 25 to 27 arc seconds.

Not too good. However the slopes were quite smooth. A

quarter turn tighter on the clutch, and until the clutch was

as tight as I could get it, the PE was in the range or 12 to

13 arc seconds but overlayed on the 4 minute cycle (that was

expected) are 4 little cycles. The slopes of these

mini-cycles are similar to the major cycle, and the changes

of direction in at the peaks and valleys whilst quite

"sharp" say +/- 3 arc secs in 20 second period, are also

similar to the peaks of the major cycles.



I have previously noted that using long guidance intervals

with the Star2000 autoguider resulted in more badly guided

shots. If I could keep the guider interval down below about

2 seconds (preferably less than 1 second) the guiding was

very significantly better. I guess using short guidance

intervals allows the Star2000 system to guide out the

"sharp" PE's where long intervals simply could not react

fast enough. Though I have not done the experiment I think

that Star2000 with a short guide interval would cope equally

well with the high range of PE experienced with the clutch

loose or the low but variable PE with the clutch tight.



Whilst the shapes of the RA curves fell into 2 camps (i.e.

those with the clutch loose/up to 1/4 turn tight, and those

with the clutch more than a 1/4 turn tight), there were

sufficient variations within each group, particularly the

group with the clutch tight that training the PEC at one

value of clutch tightness might not be applicable at another

value. This might account for why there are so many reports

of the PEC training being next to useless.



2..When the clutch was looser than 1/4 turn tight,

there was significant periodic movement of about 5 arc secs

in the DEC axis. This movement had the same 4 minute period

as the RA axis. I have absolutely know idea why there

should be crosstalk from the RA to the DEC axes. When the

clutch was tighter than 1/4 turn, the periodic motion in DEC

disappeared. This is certainly important when using

Star2000 as the guider will only guide on one axis at a

time. If it is guiding out a DEC error, Star2000 might

allow the RA error to increase above where it would normally

be controlled out. I do not know if other autoguiders have

the same characteristic.



3..I also noted that tightening the clutch changed the

average slopes of the RA and DEC curves. This suggests to

me that tightening the clutch moves the polar axis slightly.

I would love to know why. Clearly something is moving,

perhaps it is something to do with loading the bearings?



4..Despite conventional (and logical) wisdom on the

subject, PE does not vary significantly with change in scope

balance from E heavy through to W heavy. Again I have no

immediate explanation for this.



5..My previous attempt to measure PE resulted in a nice

smooth 14 arc second error. See:-

www.strachan-stephens.freeserve.co.uk/pe.htm



Unfortunately I cannot reproduce this. This mount is very

sensitive.



6..With the set up explained above, I get a data point

recorded every 2 or 3 seconds. I cannot get finer

resolution than this (unless someone can tell me how to

reduce the size of the guider window in Maxim). The

variation from point to point looks like being an accurate

gauge of the seeing conditions. The average variation

certainly changed from one night to another and I think

(more experiments required) changed as the altitude of the

chosen guide star changed with time.



Hope this all adds to the knowledge base. Now I am going

imaging.





Regards



Adam Stephens

adamstephens@...







----------------------------

#2287 Jan 24, 2001

--- In Losmandy_users@egroups.com, Adam Stephens adamstephens@a...>

wrote: > Posted to

> ccd-newastro@egroups.com

> Losmandy_users@egroups.com

> mx5c@egroups.com

>

>

. I have absolutely know idea why there > should be crosstalk from the RA to the DEC axes. When the

> @a...

Hi Adam,

Thanks for taking the time to post your findings. You are most

likely experiencing "crosstalk" because your imager is not aligned

precisely with your OTA in RA and Dec (x & y). With this being the

case, when the autoguider makes an x correction there will be some

componet of that correction that is coupled into the y axis and this

will show up as an error in your data plots. Try alinging the imager

as carefuly as you can with the RA and Dec axis of ypur mount / OTA.



Let me know if this improves your results.



Jim



----------------------------

#2302 Jan 24, 2001

Jim



The guider is not switched on. I simply measure the

displacement of the star from its initial position. No

corrections are being made.



Adam

On Wed, 24 Jan 2001 11:03:39 -0000, you wrote:



>--- In Losmandy_users@egroups.com, Adam Stephens adamstephens@a...>

>wrote:

>> Posted to

>> ccd-newastro@egroups.com

>> Losmandy_users@egroups.com

>> mx5c@egroups.com

>>

>>

>. I have absolutely know idea why there

>> should be crosstalk from the RA to the DEC axes. When the

>> @a...

>Hi Adam,

>Thanks for taking the time to post your findings. You are most

>likely experiencing "crosstalk" because your imager is not aligned

>precisely with your OTA in RA and Dec (x & y). With this being the

>case, when the autoguider makes an x correction there will be some

>componet of that correction that is coupled into the y axis and this

>will show up as an error in your data plots. Try alinging the imager

>as carefuly as you can with the RA and Dec axis of ypur mount / OTA.

>

>Let me know if this improves your results.

>

>Jim

>

>

>To unsubscribe from this group, send an email to:

>Losmandy_users-unsubscribe@egroups.com

>

>



----------------------------

#2305 Jan 24, 2001

I guess that's my point...whyIf the guider guides ...go for it.

Six months aga,and for alsmost a year,I could guide better on my g-11 than

the st-4 could.I got Losmandy and SBIG involved and probably spent more on

phone calls from Canada than the st-4 cost.

Eventually it proved to be the mount (not the st-4 or the operator)

A big waste of time,effort and money.

Changed a few bearings,slacked off worm pressure,polished/lapped worm and

voila,can now hold a star at 1/2 pixel or better for 3 hours(with st-7e)

Round stars,no trailing and at -40C.

Personally,I don't know what the mount can do without guiding (except in dec

is can hold a star on polar alignment at less than 1/3 a star in east and

west for just about forever)



Now I just take pictures (of course,the weather hasn,t cooperated since I

got the mount fixed>



C'est la vie



Jimmy



>From: Adam Stephens adamstephens@...>

>Reply-To: Losmandy_users@egroups.com

>To: Losmandy_users@egroups.com

>Subject: Re: [Losmandy_users] Re: Losmandy G11 Periodic Error variability

>and sensitivity

>Date: Wed, 24 Jan 2001 19:39:31 +0000

>

>Jim

>

>The guider is not switched on. I simply measure the

>displacement of the star from its initial position. No

>corrections are being made.

>

>Adam

>

>On Wed, 24 Jan 2001 11:03:39 -0000, you wrote:

>

> >--- In Losmandy_users@egroups.com, Adam Stephens adamstephens@a...>

> >wrote:

> >> Posted to

> >> ccd-newastro@egroups.com

> >> Losmandy_users@egroups.com

> >> mx5c@egroups.com

> >>

> >>

> >. I have absolutely know idea why there

> >> should be crosstalk from the RA to the DEC axes. When the

> >> @a...

> >Hi Adam,

> >Thanks for taking the time to post your findings. You are most

> >likely experiencing "crosstalk" because your imager is not aligned

> >precisely with your OTA in RA and Dec (x & y). With this being the

> >case, when the autoguider makes an x correction there will be some

> >componet of that correction that is coupled into the y axis and this

> >will show up as an error in your data plots. Try alinging the imager

> >as carefuly as you can with the RA and Dec axis of ypur mount / OTA.

> >

> >Let me know if this improves your results.

> >

> >Jim

> >

> >

> >To unsubscribe from this group, send an email to:

> >Losmandy_users-unsubscribe@egroups.com

> >

> >

>

>

>To unsubscribe from this group, send an email to:

>Losmandy_users-unsubscribe@egroups.com

>

>

>



---------------

Get Your Private, Free E-mail from MSN Hotmail at www.hotmail.com







----------------------------

#2307 Jan 24, 2001

Jimmy



Sorry I should have read your post better. I did line up

the camera by eye so that it was at least reasonably well

aligned I would guess well within 5 degrees. I will take

more care next time to get it a as perfect as possible. I

guess the best way would be to turn off the drive a check a

star trail is horizontal.



Well done with your mount BTW sounds good now, but with too

much effort on your part. At the moment I have little

confidence that I can repeat these little experiments there

seems to be a great many variables. What was the big driver

in the improvement of your mount?



Adam





On Wed, 24 Jan 2001 20:16:35 -0000, you wrote:



>I guess that's my point...whyIf the guider guides ...go for it.

>Six months aga,and for alsmost a year,I could guide better on my g-11 than

>the st-4 could.I got Losmandy and SBIG involved and probably spent more on

>phone calls from Canada than the st-4 cost.

>Eventually it proved to be the mount (not the st-4 or the operator)

>A big waste of time,effort and money.

>Changed a few bearings,slacked off worm pressure,polished/lapped worm and

>voila,can now hold a star at 1/2 pixel or better for 3 hours(with st-7e)

>Round stars,no trailing and at -40C.

>Personally,I don't know what the mount can do without guiding (except in dec

>is can hold a star on polar alignment at less than 1/3 a star in east and

>west for just about forever)

>

>Now I just take pictures (of course,the weather hasn,t cooperated since I

>got the mount fixed>

>

>C'est la vie

>

>Jimmy

>

>

>>From: Adam Stephens adamstephens@...>

>>Reply-To: Losmandy_users@egroups.com

>>To: Losmandy_users@egroups.com

>>Subject: Re: [Losmandy_users] Re: Losmandy G11 Periodic Error variability

>>and sensitivity

>>Date: Wed, 24 Jan 2001 19:39:31 +0000

>>

>>Jim

>>

>>The guider is not switched on. I simply measure the

>>displacement of the star from its initial position. No

>>corrections are being made.

>>

>>Adam

>>

>>On Wed, 24 Jan 2001 11:03:39 -0000, you wrote:

>>

>> >--- In Losmandy_users@egroups.com, Adam Stephens adamstephens@a...>

>> >wrote:

>> >> Posted to

>> >> ccd-newastro@egroups.com

>> >> Losmandy_users@egroups.com

>> >> mx5c@egroups.com

>> >>

>> >>

>> >. I have absolutely know idea why there

>> >> should be crosstalk from the RA to the DEC axes. When the

>> >> @a...

>> >Hi Adam,

>> >Thanks for taking the time to post your findings. You are most

>> >likely experiencing "crosstalk" because your imager is not aligned

>> >precisely with your OTA in RA and Dec (x & y). With this being the

>> >case, when the autoguider makes an x correction there will be some

>> >componet of that correction that is coupled into the y axis and this

>> >will show up as an error in your data plots. Try alinging the imager

>> >as carefuly as you can with the RA and Dec axis of ypur mount / OTA.

>> >

>> >Let me know if this improves your results.

>> >

>> >Jim

>> >

>> >

>> >To unsubscribe from this group, send an email to:

>> >Losmandy_users-unsubscribe@egroups.com

>> >

>> >

>>

>>

>>To unsubscribe from this group, send an email to:

>>Losmandy_users-unsubscribe@egroups.com

>>

>>

>>

>

---------------

>Get Your Private, Free E-mail from MSN Hotmail at www.hotmail.com

>

>

>To unsubscribe from this group, send an email to:

>Losmandy_users-unsubscribe@egroups.com

>

>



----------------------------

#2308 Jan 24, 2001

Also, if the RA and DEC axes are not orthogonal there is a "cross-talk".



jbrinsfi@... wrote:

> --- In Losmandy_users@egroups.com, Adam Stephens adamstephens@a...>

> wrote:

> > Posted to

> > ccd-newastro@egroups.com

> > Losmandy_users@egroups.com

> > mx5c@egroups.com

> >

> >

> . I have absolutely know idea why there

> > should be crosstalk from the RA to the DEC axes. When the

> > @a...

> Hi Adam,

> Thanks for taking the time to post your findings. You are most

> likely experiencing "crosstalk" because your imager is not aligned

> precisely with your OTA in RA and Dec (x & y). With this being the

> case, when the autoguider makes an x correction there will be some

> componet of that correction that is coupled into the y axis and this

> will show up as an error in your data plots. Try alinging the imager

> as carefuly as you can with the RA and Dec axis of ypur mount / OTA.

>

> Let me know if this improves your results.

>

> Jim

>

>

> eGroups Sponsor

[Choose 3 DVDs for $0.49 each!]

Choose 3 DVDs for $0.49 each!

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com

>

>



--

Rob Watson

members.home.net/robonthemove/







----------------------------

#2314 Jan 24, 2001

5 degrees doesn't sound like much but just figure out how many pixels are

affected.When you are dealing in microns,I've found that 1 or 2 pixels off

is enough to generate a synergy in corrections betwen ra and dec.these

correct at different speeds and so you want to reduce the motion as much as

possible because the mount is sensitive to a degree of self induced

vibes.(see original sky/tel review)



The biggest change on mine was worm bearings that had flat spots and also

slacking off the pressure between gear and worm.



Jimmy

>From: Adam Stephens adamstephens@...>

>Reply-To: Losmandy_users@egroups.com

>To: Losmandy_users@egroups.com

>Subject: Re: [Losmandy_users] Re: Losmandy G11 Periodic Error variability

>and sensitivity

>Date: Wed, 24 Jan 2001 20:38:02 +0000

>

>Jimmy

>

>Sorry I should have read your post better. I did line up

>the camera by eye so that it was at least reasonably well

>aligned I would guess well within 5 degrees. I will take

>more care next time to get it a as perfect as possible. I

>guess the best way would be to turn off the drive a check a

>star trail is horizontal.

>

>Well done with your mount BTW sounds good now, but with too

>much effort on your part. At the moment I have little

>confidence that I can repeat these little experiments there

>seems to be a great many variables. What was the big driver

>in the improvement of your mount?

>

>Adam

>

>

>

>On Wed, 24 Jan 2001 20:16:35 -0000, you wrote:

>

> >I guess that's my point...whyIf the guider guides ...go for it.

> >Six months aga,and for alsmost a year,I could guide better on my g-11

>than

> >the st-4 could.I got Losmandy and SBIG involved and probably spent more

>on

> >phone calls from Canada than the st-4 cost.

> >Eventually it proved to be the mount (not the st-4 or the operator)

> >A big waste of time,effort and money.

> >Changed a few bearings,slacked off worm pressure,polished/lapped worm and

> >voila,can now hold a star at 1/2 pixel or better for 3 hours(with st-7e)

> >Round stars,no trailing and at -40C.

> >Personally,I don't know what the mount can do without guiding (except in

>dec

> >is can hold a star on polar alignment at less than 1/3 a star in east and

> >west for just about forever)

> >

> >Now I just take pictures (of course,the weather hasn,t cooperated since I

> >got the mount fixed>

> >

> >C'est la vie

> >

> >Jimmy

> >

> >

> >>From: Adam Stephens adamstephens@...>

> >>Reply-To: Losmandy_users@egroups.com

> >>To: Losmandy_users@egroups.com

> >>Subject: Re: [Losmandy_users] Re: Losmandy G11 Periodic Error

>variability

> >>and sensitivity

> >>Date: Wed, 24 Jan 2001 19:39:31 +0000

> >>

> >>Jim

> >>

> >>The guider is not switched on. I simply measure the

> >>displacement of the star from its initial position. No

> >>corrections are being made.

> >>

> >>Adam

> >>

> >>On Wed, 24 Jan 2001 11:03:39 -0000, you wrote:

> >>

> >> >--- In Losmandy_users@egroups.com, Adam Stephens adamstephens@a...>

> >> >wrote:

> >> >> Posted to

> >> >> ccd-newastro@egroups.com

> >> >> Losmandy_users@egroups.com

> >> >> mx5c@egroups.com

> >> >>

> >> >>

> >> >. I have absolutely know idea why there

> >> >> should be crosstalk from the RA to the DEC axes. When the

> >> >> @a...

> >> >Hi Adam,

> >> >Thanks for taking the time to post your findings. You are most

> >> >likely experiencing "crosstalk" because your imager is not aligned

> >> >precisely with your OTA in RA and Dec (x & y). With this being the

> >> >case, when the autoguider makes an x correction there will be some

> >> >componet of that correction that is coupled into the y axis and this

> >> >will show up as an error in your data plots. Try alinging the imager

> >> >as carefuly as you can with the RA and Dec axis of ypur mount / OTA.

> >> >

> >> >Let me know if this improves your results.

> >> >

> >> >Jim

> >> >

> >> >

> >> >To unsubscribe from this group, send an email to:

> >> >Losmandy_users-unsubscribe@egroups.com

> >> >

> >> >

> >>

> >>

> >>To unsubscribe from this group, send an email to:

> >>Losmandy_users-unsubscribe@egroups.com

> >>

> >>

> >>

> >

---------------

> >Get Your Private, Free E-mail from MSN Hotmail at www.hotmail.com

> >

> >

> >To unsubscribe from this group, send an email to:

> >Losmandy_users-unsubscribe@egroups.com

> >

> >

>

>

>To unsubscribe from this group, send an email to:

>Losmandy_users-unsubscribe@egroups.com

>

>

>



---------------

Get Your Private, Free E-mail from MSN Hotmail at www.hotmail.com







----------------------------

#7266 Dec 12, 2001

I am about to buy a G11 2nd hand to mount my Genesis SDF on. Primary

use would be astrophotography. However I am concerned about the

stories I have heard about the periodic error.



I would appricaite any info on this front as I am about to part with

a lot of cash!



Thanks all!



----------------------------

#7267 Dec 12, 2001

grass_snake wrote: > I am about to buy a G11 2nd hand to mount my Genesis SDF on. Primary

> use would be astrophotography. However I am concerned about the

> stories I have heard about the periodic error.

>

> I would appricaite any info on this front as I am about to part with

> a lot of cash!



I'm new to the list, but will chime in...

I bought a new G-11 three weeks ago, after using a 10" LX200 for almost 2 years. I made the decision to sell the SCT and get the Losmandy after realizing that my LX200 had spent the better part of the past year simply being a "mount" for my imaging uses (with a TV refractor piggy-backed on it). I wanted to get bigger payload capacity, more stability, and better tracking performance. Well, I got 2 out of 3...



Frankly, my new G-11 does not track as well as the LX200 did, even with PEC trained (and it's a shame you have to retrain it every time you turn the mount back on). I've measured the PE of the G-11 at approximately 13 arc-seconds pp, which isn't a bad total, but there are two points on the worm where it swings quickly and wildly to that extreme, making it difficult to guide out. The LX200 had about 20 arc-secs without PEC, but it was all pretty smooth and regular and easily taken care of by an autoguider. With the PEC on, I can get the Losmandy down to about 9 (best I've done in about 5 tries), the LX200 got down to 7. In calm wind conditions, autoguiding the LX200 was always easy, I'm still struggling with the G-11.



Now, I haven't done any adjustments to the worm tension, bearings, re-greasing, or any of the other fine suggestions that most owners give...at least not yet. Working carefully on the mount balance (slight bias to the East) and clutch tightness, I've been able to smooth out the wild swings a bit, and can often guide successfully now. I have no doubt that I'll be able to tinker with it a bit more and get it performing even better. And when you compare stability and load capacity, well the G-11 is a rock compared to the LX200 on a superwedge! I actually imaged NGC1977 last Friday night in wind gusts up to 30 MPH or so, and only had to throw out two frames out of more than 2 hours of exposures, that's how solid it is.



I have to admit that I do miss the LX200's dead-on GOTO...but I have DSCs for the G-11 and they get the job done. I think my biggest disappointment has been spending a fair chunk of cash and then having to do a bunch of tinkering and fine tuning myself to get the mount into the condition it should have been when it left the factory. I would have gladly spent another $500 or so to have the Losmandy guys do the extra bit to make it work better that I'm having to do now...right now I'd say I'm satisfied with qualifications, and when you look at the competition, there isn't a mount that will carry this weight with this precision available from any other manufacturer near the G-11's price.



Hope that long-winded diatribe helps!

Paul



CCD Galleries:

members.home.net/astronomyresource/mx7c/mx7c.htm

members.home.net/scopebuilding/hx916.htm



----------------------------

#7268 Dec 12, 2001

Dude,



Despite all that is said on this group about PE and the G-11,

the G-11 produces excellent results given its cost and the size

of its gears.



The G-11 is simply a great value and hence its popularity.

By a good value I mean good performance at a good price.



This really becomes apparent when you start looking at mounts

that are the next step-up from a G-11; e.g. MI250, HGM200,

AP900, etc. These mounts cost many thousands of dollars more

than the G-11 ($2,000 - $5,000 MORE than the G-11 depending

on which mount we are talking about). Of course they come

out of the box full goto (even voice activated in the case

of the AP900!), but what we are mostly interested in is the

PE and pointing accuracy of the mount as far as this discussion

goes. Don't forget too that some of these mounts have waiting

lists that are over a year long.



From my experience you can expect to have about 10-12 arc-seconds

of PE on a G-11 peak-to-peak. Get good at PEC training and you can

probably cut it in half or more (however, the use of PEC with

autoguiding seems to be a controversial subject).



Some G-11 owners seem to have mounts that are "sweet" and perform

very well right out of the box. Others have "fiddled" with their

mounts in various ways to improve performance. In any case the

G-11 is still IMHO the best value on the market today and for

pure visual work is an absolutely solid mount.



My advice would be to do either of the following:



1. Buy the G-11. See if it works for you. If not, then sell it.

Despite recent events (economy, Afghanistan, etc.) I believe

the used G-11 market is still quite active. You might be out

a few hundred bucks after all is said and done at the most.



2. Bite the bullet and shell out the dough for that AP900 and

be prepared to wait.



If you do get the G-11, be sure and spend enough time with the

mount to really give it a good run for its money before you

throw in the towel. There is a learning curve to come up on

any mount that takes quite a few sessions under dark skies to

get past.



Good Luck!







-----Original Message-----

From: grass_snake_man [mailto:grass_snake_man@...]

Sent: Wednesday, December 12, 2001 8:26 AM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] G11, PEC concerns!





I am about to buy a G11 2nd hand to mount my Genesis SDF on. Primary

use would be astrophotography. However I am concerned about the

stories I have heard about the periodic error.



I would appricaite any info on this front as I am about to part with

a lot of cash!



Thanks all!







To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/







----------------------------

#7269 Dec 12, 2001

Paul,



What do you think about polar alignment between the LX200 on the

superwedge and the G-11?



I used to be a fork-mount guy too. Had an LX200 on a Mettler wedge.

I always struggled with polar alignment on the wedge. If I ever

did get good alignment, it would not stay that way for long.



It's a snap with the G-11. And once done its rock solid.



This is at least one thing I was glad about after I made the change

from the LX to the G-11.



But I agree with you on the PE of the G-11 as compared to the LX200

in all respects. What I have been struggling with are the "wild"

swings you mentioned.



The difference in PE between the G-11 and the LX200 kind of makes

sense though. The LX200 uses servos. Some PE shots of the G-11

before and after the Gemini upgrade have shown an improvement

in PE on the G-11. See the files section of the group.



The LX200 only has a slightly larger RA gear than the G-11 if I'm not

mistaken. So, I do not think the gear size accounts for the LX200's

perceived "better" PE.



I have one of the "new" motors for the G-11, but trying to get the

weather, my family, and my job to all cooperate has kept me from

testing it out.



Besides. The G-11 just looks cool too don't you think?



-----Original Message-----

From: Paul LeFevre [mailto:lefevre@...]

Sent: Wednesday, December 12, 2001 8:50 AM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] G11, PEC concerns!





grass_snake wrote: > I am about to buy a G11 2nd hand to mount my Genesis SDF on. Primary

> use would be astrophotography. However I am concerned about the

> stories I have heard about the periodic error.

>

> I would appricaite any info on this front as I am about to part with

> a lot of cash!



I'm new to the list, but will chime in...

I bought a new G-11 three weeks ago, after using a 10" LX200 for almost 2

years. I made the decision to sell the SCT and get the Losmandy after

realizing that my LX200 had spent the better part of the past year simply

being a "mount" for my imaging uses (with a TV refractor piggy-backed on

it). I wanted to get bigger payload capacity, more stability, and better

tracking performance. Well, I got 2 out of 3...



Frankly, my new G-11 does not track as well as the LX200 did, even with PEC

trained (and it's a shame you have to retrain it every time you turn the

mount back on). I've measured the PE of the G-11 at approximately 13

arc-seconds pp, which isn't a bad total, but there are two points on the

worm where it swings quickly and wildly to that extreme, making it difficult

to guide out. The LX200 had about 20 arc-secs without PEC, but it was all

pretty smooth and regular and easily taken care of by an autoguider. With

the PEC on, I can get the Losmandy down to about 9 (best I've done in about

5 tries), the LX200 got down to 7. In calm wind conditions, autoguiding the

LX200 was always easy, I'm still struggling with the G-11.



Now, I haven't done any adjustments to the worm tension, bearings,

re-greasing, or any of the other fine suggestions that most owners give...at

least not yet. Working carefully on the mount balance (slight bias to the

East) and clutch tightness, I've been able to smooth out the wild swings a

bit, and can often guide successfully now. I have no doubt that I'll be

able to tinker with it a bit more and get it performing even better. And

when you compare stability and load capacity, well the G-11 is a rock

compared to the LX200 on a superwedge! I actually imaged NGC1977 last

Friday night in wind gusts up to 30 MPH or so, and only had to throw out two

frames out of more than 2 hours of exposures, that's how solid it is.



I have to admit that I do miss the LX200's dead-on GOTO...but I have DSCs

for the G-11 and they get the job done. I think my biggest disappointment

has been spending a fair chunk of cash and then having to do a bunch of

tinkering and fine tuning myself to get the mount into the condition it

should have been when it left the factory. I would have gladly spent

another $500 or so to have the Losmandy guys do the extra bit to make it

work better that I'm having to do now...right now I'd say I'm satisfied with

qualifications, and when you look at the competition, there isn't a mount

that will carry this weight with this precision available from any other

manufacturer near the G-11's price.



Hope that long-winded diatribe helps!

Paul



CCD Galleries:

members.home.net/astronomyresource/mx7c/mx7c.htm

members.home.net/scopebuilding/hx916.htm











To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/



----------------------------

#7271 Dec 12, 2001

Lacey James wrote: > What do you think about polar alignment between the LX200 on the

> superwedge and the G-11?

> I used to be a fork-mount guy too. Had an LX200 on a Mettler wedge.

> I always struggled with polar alignment on the wedge. If I ever

> did get good alignment, it would not stay that way for long.

> It's a snap with the G-11. And once done its rock solid.

> This is at least one thing I was glad about after I made the change

> from the LX to the G-11.



No argument there, polar aligning the G-11 is a snap (and I should have mentioned that!), with the polar alignment scope. I did the standard routine, carefully drift aligned one night, then aligned the polar scope to match. Now I can just plop the mount down, use the polar scope, and be close enough that DEC corrections are almost non-existant. I would typically spend 20-30 minutes drfit aligning the LX200 on the wedge every single outing.

> But I agree with you on the PE of the G-11 as compared to the LX200

> in all respects. What I have been struggling with are the "wild"

> swings you mentioned.

> The difference in PE between the G-11 and the LX200 kind of makes

> sense though. The LX200 uses servos. Some PE shots of the G-11

> before and after the Gemini upgrade have shown an improvement

> in PE on the G-11. See the files section of the group.

> The LX200 only has a slightly larger RA gear than the G-11 if I'm not

> mistaken. So, I do not think the gear size accounts for the LX200's

> perceived "better" PE.

> I have one of the "new" motors for the G-11, but trying to get the

> weather, my family, and my job to all cooperate has kept me from

> testing it out.

> Besides. The G-11 just looks cool too don't you think?



It does indeed look cool :) My new mount has the SAIA Swiss steppers, so I don't know if they're better than the older ones, just that the "wild swings" still happen with the SAIA versions. I honestly don't think the PE swings have much if anything to do with the motors (of course I could be wrong), it just seems to be all gear related. In a way that's very good news, as it means that gear adjustment, worm adjustment, and possibly lapping the gears could reduce my swings and eliminate the problem. As the rest of the mount's fit, finish, operation, stability, etc. are all top-notch, I have high hopes that I can solve my one little problem and be completely satisfied :)



Paul







----------------------------

#7272 Dec 12, 2001

Crap. I didn't want to hear that about the motors.



But I guess I shouldn't be too surprised.



I will still keep my fingers crossed and hope that

the new motor is better. I've always felt like my

steppers don't step "evenly" anyway. If nothing else

I will have a spare I suppose.



If that does not work I'm going to try and ruin my RA

gear and worm by lapping them. Another set will

only cost me a $100 or a little more anyway.



I'm off to McMaster Carr to order some lapping compound!



Thx!



-----Original Message-----

From: Paul LeFevre [mailto:lefevre@...]

Sent: Wednesday, December 12, 2001 9:35 AM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] G11, PEC concerns!





Lacey James wrote: > What do you think about polar alignment between the LX200 on the

> superwedge and the G-11?

> I used to be a fork-mount guy too. Had an LX200 on a Mettler wedge.

> I always struggled with polar alignment on the wedge. If I ever

> did get good alignment, it would not stay that way for long.

> It's a snap with the G-11. And once done its rock solid.

> This is at least one thing I was glad about after I made the change

> from the LX to the G-11.



No argument there, polar aligning the G-11 is a snap (and I should have

mentioned that!), with the polar alignment scope. I did the standard

routine, carefully drift aligned one night, then aligned the polar scope to

match. Now I can just plop the mount down, use the polar scope, and be

close enough that DEC corrections are almost non-existant. I would

typically spend 20-30 minutes drfit aligning the LX200 on the wedge every

single outing.

> But I agree with you on the PE of the G-11 as compared to the LX200

> in all respects. What I have been struggling with are the "wild"

> swings you mentioned.

> The difference in PE between the G-11 and the LX200 kind of makes

> sense though. The LX200 uses servos. Some PE shots of the G-11

> before and after the Gemini upgrade have shown an improvement

> in PE on the G-11. See the files section of the group.

> The LX200 only has a slightly larger RA gear than the G-11 if I'm not

> mistaken. So, I do not think the gear size accounts for the LX200's

> perceived "better" PE.

> I have one of the "new" motors for the G-11, but trying to get the

> weather, my family, and my job to all cooperate has kept me from

> testing it out.

> Besides. The G-11 just looks cool too don't you think?



It does indeed look cool :) My new mount has the SAIA Swiss steppers, so I

don't know if they're better than the older ones, just that the "wild

swings" still happen with the SAIA versions. I honestly don't think the PE

swings have much if anything to do with the motors (of course I could be

wrong), it just seems to be all gear related. In a way that's very good

news, as it means that gear adjustment, worm adjustment, and possibly

lapping the gears could reduce my swings and eliminate the problem. As the

rest of the mount's fit, finish, operation, stability, etc. are all

top-notch, I have high hopes that I can solve my one little problem and be

completely satisfied :)



Paul











To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/



----------------------------

#7277 Dec 12, 2001

I just ordered some of the 2 micron diamond lapping compound. This

should be interesting.



Allen



----------------------------

#7280 Dec 12, 2001

Allen wrote: > I just ordered some of the 2 micron diamond lapping compound. This

> should be interesting.



I'll be anxiously waiting to hear your results!



Paul



----------------------------

#7286 Dec 13, 2001

Thanks Guys! I am sold. I pick up my G11 on Saturday. Hopefully I

will be as happy as you guys seem to be, I like tinkering with stuff,

always more satisfying if you can improve on a product, if you see

what I mean!



I will be paying close attention to this site from now on!



Deren.



--- In Losmandy_users@y..., Lacey James-CJL023 james.lacey@m...>

wrote: > Paul,

>

> What do you think about polar alignment between the LX200 on the

> superwedge and the G-11?

>

> I used to be a fork-mount guy too. Had an LX200 on a Mettler wedge.

> I always struggled with polar alignment on the wedge. If I ever

> did get good alignment, it would not stay that way for long.

>

> It's a snap with the G-11. And once done its rock solid.

>

> This is at least one thing I was glad about after I made the change

> from the LX to the G-11.

>

> But I agree with you on the PE of the G-11 as compared to the LX200

> in all respects. What I have been struggling with are the "wild"

> swings you mentioned.

>

> The difference in PE between the G-11 and the LX200 kind of makes

> sense though. The LX200 uses servos. Some PE shots of the G-11

> before and after the Gemini upgrade have shown an improvement

> in PE on the G-11. See the files section of the group.

>

> The LX200 only has a slightly larger RA gear than the G-11 if I'm

not > mistaken. So, I do not think the gear size accounts for the LX200's

> perceived "better" PE.

>

> I have one of the "new" motors for the G-11, but trying to get the

> weather, my family, and my job to all cooperate has kept me from

> testing it out.

>

> Besides. The G-11 just looks cool too don't you think?

>

> -----Original Message-----

> From: Paul LeFevre [mailto:lefevre@m...]

> Sent: Wednesday, December 12, 2001 8:50 AM

> To: Losmandy_users@y...

> Subject: RE: [Losmandy_users] G11, PEC concerns!

>

>

> grass_snake wrote:

> > I am about to buy a G11 2nd hand to mount my Genesis SDF on.

Primary > > use would be astrophotography. However I am concerned about the

> > stories I have heard about the periodic error.

> >

> > I would appricaite any info on this front as I am about to part

with > > a lot of cash!

>

> I'm new to the list, but will chime in...

> I bought a new G-11 three weeks ago, after using a 10" LX200 for

almost 2 > years. I made the decision to sell the SCT and get the Losmandy

after > realizing that my LX200 had spent the better part of the past year

simply > being a "mount" for my imaging uses (with a TV refractor piggy-

backed on > it). I wanted to get bigger payload capacity, more stability, and

better > tracking performance. Well, I got 2 out of 3...

>

> Frankly, my new G-11 does not track as well as the LX200 did, even

with PEC > trained (and it's a shame you have to retrain it every time you

turn the > mount back on). I've measured the PE of the G-11 at approximately

13 > arc-seconds pp, which isn't a bad total, but there are two points

on the > worm where it swings quickly and wildly to that extreme, making it

difficult > to guide out. The LX200 had about 20 arc-secs without PEC, but it

was all > pretty smooth and regular and easily taken care of by an

autoguider. With > the PEC on, I can get the Losmandy down to about 9 (best I've done

in about > 5 tries), the LX200 got down to 7. In calm wind conditions,

autoguiding the > LX200 was always easy, I'm still struggling with the G-11.

>

> Now, I haven't done any adjustments to the worm tension, bearings,

> re-greasing, or any of the other fine suggestions that most owners

give...at > least not yet. Working carefully on the mount balance (slight bias

to the > East) and clutch tightness, I've been able to smooth out the wild

swings a > bit, and can often guide successfully now. I have no doubt that

I'll be > able to tinker with it a bit more and get it performing even

better. And > when you compare stability and load capacity, well the G-11 is a

rock > compared to the LX200 on a superwedge! I actually imaged NGC1977

last > Friday night in wind gusts up to 30 MPH or so, and only had to

throw out two > frames out of more than 2 hours of exposures, that's how solid it

is. >

> I have to admit that I do miss the LX200's dead-on GOTO...but I

have DSCs > for the G-11 and they get the job done. I think my biggest

disappointment > has been spending a fair chunk of cash and then having to do a

bunch of > tinkering and fine tuning myself to get the mount into the

condition it > should have been when it left the factory. I would have gladly

spent > another $500 or so to have the Losmandy guys do the extra bit to

make it > work better that I'm having to do now...right now I'd say I'm

satisfied with > qualifications, and when you look at the competition, there isn't a

mount > that will carry this weight with this precision available from any

other > manufacturer near the G-11's price.

>

> Hope that long-winded diatribe helps!

> Paul

>

> CCD Galleries:

> members.home.net/astronomyresource/mx7c/mx7c.htm

> members.home.net/scopebuilding/hx916.htm

>

>

>

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@e...

>

>

>

> Your use of Yahoo! Groups is subject to

docs.yahoo.com/info/terms/







----------------------------

#7406 Dec 24, 2001

I noted something recently that may be of interest. I have been using

the G11 for a couple years now. When first recieved I was using a

C11 on it and I measured only about 6" or so PE uncorrected.



Then recently have been working with a C8 and CCD, and have been

battling some tracking issues. Just track and accumulate as I have

not autoguider. I had even noted in here before problems with light

breezes. I recenlty added a guidescope which with all losmandy

mounting hardware such as addtional dovetail, dovetail adapters rings

and scope, 2" diag, ep and camera add a significant amount of weight

which required the 21 lb weight to be put back on.



When doing some guided photos, I noticed I hardly had to make any

corrections over 10 minutes. It was tracking like a dream, kind of

like the C11 did. This may be due to balance. I have noted with CCD

results that the mount tracks better perfectly balanced rather than

rule of thumb weighting to east. But with 11 lb weight and C8 alone,

balance is tough to judge as there is some inherant friction in mount

so you can slide weight back and forth a fair amount and it won't

move one way or another. But higher instrument load and 21lb weight,

there is little guess where balance is.



Does this make sense?, anybody seen similar results?



Kevin



----------------------------

#7407 Dec 24, 2001

Yes, I've noticed that balance is critical, though I haven't

noticed that it makes a difference with regards to loading

as I generally have more than 21 lbs of counterweight loaded.



I use an STV autoguider and have noticed that when I have

bad tracking performance in one axis, if I tweak the

counterweight a little, the tracking errors can be cut

in half or more (they should at least be the same in both

axes if it is due to seeing).



Dave Kodama

--- In Losmandy_users@y..., "bizman2001" _kevin1231@e...> wrote:

> I noted something recently that may be of interest. I have been

using

> the G11 for a couple years now. When first recieved I was using a

> C11 on it and I measured only about 6" or so PE uncorrected.

>

> Then recently have been working with a C8 and CCD, and have been

> battling some tracking issues. Just track and accumulate as I have

> not autoguider. I had even noted in here before problems with light

> breezes. I recenlty added a guidescope which with all losmandy

> mounting hardware such as addtional dovetail, dovetail adapters

rings

> and scope, 2" diag, ep and camera add a significant amount of

weight

> which required the 21 lb weight to be put back on.

>

> When doing some guided photos, I noticed I hardly had to make any

> corrections over 10 minutes. It was tracking like a dream, kind of

> like the C11 did. This may be due to balance. I have noted with

CCD

> results that the mount tracks better perfectly balanced rather than

> rule of thumb weighting to east. But with 11 lb weight and C8

alone,

> balance is tough to judge as there is some inherant friction in

mount

> so you can slide weight back and forth a fair amount and it won't

> move one way or another. But higher instrument load and 21lb

weight,

> there is little guess where balance is.

>

> Does this make sense?, anybody seen similar results?

>

> Kevin



----------------------------

#7427 Dec 25, 2001

I'm a newbie -- about a week -- owner of a G-11 and I'm still using my

C8 on the mount. I have noticed how hard it is to judge balance by

touch with a light light load, though. I use a cheap (about $6) spring

scale from Edmund Scientific

(www.ScientificsOnline.com/Products/DisplayProduct.cfm?producti

d=8190). It has a hook on one end and it's easy to hook on the scope

and measure the pull it takes to swing the OTA up and down in both RA

and DEC. Being a new owner, I'm still in the shimming for orthogonal

and worm gear adjustment stage, so I can't comment on tracking yet,

but I'm sure I'm get a better balance using the scale.



Robert Burns

--- In Losmandy_users@y..., "d_kodama" kodama@a...> wrote:

> Yes, I've noticed that balance is critical, though I haven't

> noticed that it makes a difference with regards to loading

> as I generally have more than 21 lbs of counterweight loaded.

>

> I use an STV autoguider and have noticed that when I have

> bad tracking performance in one axis, if I tweak the

> counterweight a little, the tracking errors can be cut

> in half or more (they should at least be the same in both

> axes if it is due to seeing).

>

> Dave Kodama

>

> --- In Losmandy_users@y..., "bizman2001" _kevin1231@e...> wrote:

> > I noted something recently that may be of interest. I have been

> using

> > the G11 for a couple years now. When first recieved I was using a

> > C11 on it and I measured only about 6" or so PE uncorrected.

> >

> > Then recently have been working with a C8 and CCD, and have been

> > battling some tracking issues. Just track and accumulate as I

have

> > not autoguider. I had even noted in here before problems with

light

> > breezes. I recenlty added a guidescope which with all losmandy

> > mounting hardware such as addtional dovetail, dovetail adapters

> rings

> > and scope, 2" diag, ep and camera add a significant amount of

> weight

> > which required the 21 lb weight to be put back on.

> >

> > When doing some guided photos, I noticed I hardly had to make any

> > corrections over 10 minutes. It was tracking like a dream, kind of

> > like the C11 did. This may be due to balance. I have noted with

> CCD

> > results that the mount tracks better perfectly balanced rather

than

> > rule of thumb weighting to east. But with 11 lb weight and C8

> alone,

> > balance is tough to judge as there is some inherant friction in

> mount

> > so you can slide weight back and forth a fair amount and it won't

> > move one way or another. But higher instrument load and 21lb

> weight,

> > there is little guess where balance is.

> >

> > Does this make sense?, anybody seen similar results?

> >

> > Kevin







----------------------------

#7438 Dec 26, 2001

Yea, what I've noticed is that it is much harder to judge the light

loads. What is important to note that is against conventional

thinking is NOT to load mount to east. I have found better tracking

when perfectly balanced. Don't know why. But when perfectly

balanced, I am getting a nice smooth 7" of error. Loaded to east,

12 or more. I just wish mount was so smooth, that even with light

load it would swing easily with just an ever so slight imbalance.



I am not sure, but I believe the inherant resistance leads to some

of the tracking accuracy issues.



Kevin

--- In Losmandy_users@y..., "rdburns2002" rd-burns@t...> wrote:

> I'm a newbie -- about a week -- owner of a G-11 and I'm still

using my

> C8 on the mount. I have noticed how hard it is to judge balance by

> touch with a light light load, though. I use a cheap (about $6)

spring

> scale from Edmund Scientific

> (www.ScientificsOnline.com/Products/DisplayProduct.cfm?

producti

> d=8190). It has a hook on one end and it's easy to hook on the

scope

> and measure the pull it takes to swing the OTA up and down in both

RA

> and DEC. Being a new owner, I'm still in the shimming for

orthogonal

> and worm gear adjustment stage, so I can't comment on tracking

yet,

> but I'm sure I'm get a better balance using the scale.

>

> Robert Burns

>

> --- In Losmandy_users@y..., "d_kodama" kodama@a...> wrote:

> > Yes, I've noticed that balance is critical, though I haven't

> > noticed that it makes a difference with regards to loading

> > as I generally have more than 21 lbs of counterweight loaded.

> >

> > I use an STV autoguider and have noticed that when I have

> > bad tracking performance in one axis, if I tweak the

> > counterweight a little, the tracking errors can be cut

> > in half or more (they should at least be the same in both

> > axes if it is due to seeing).

> >

> > Dave Kodama

> >

> > --- In Losmandy_users@y..., "bizman2001" _kevin1231@e...> wrote:

> > > I noted something recently that may be of interest. I have

been

> > using

> > > the G11 for a couple years now. When first recieved I was

using a

> > > C11 on it and I measured only about 6" or so PE uncorrected.

> > >

> > > Then recently have been working with a C8 and CCD, and have

been

> > > battling some tracking issues. Just track and accumulate as I

> have

> > > not autoguider. I had even noted in here before problems with

> light

> > > breezes. I recenlty added a guidescope which with all losmandy

> > > mounting hardware such as addtional dovetail, dovetail

adapters

> > rings

> > > and scope, 2" diag, ep and camera add a significant amount of

> > weight

> > > which required the 21 lb weight to be put back on.

> > >

> > > When doing some guided photos, I noticed I hardly had to make

any

> > > corrections over 10 minutes. It was tracking like a dream,

kind of

> > > like the C11 did. This may be due to balance. I have noted

with

> > CCD

> > > results that the mount tracks better perfectly balanced rather

> than

> > > rule of thumb weighting to east. But with 11 lb weight and C8

> > alone,

> > > balance is tough to judge as there is some inherant friction

in

> > mount

> > > so you can slide weight back and forth a fair amount and it

won't

> > > move one way or another. But higher instrument load and 21lb

> > weight,

> > > there is little guess where balance is.

> > >

> > > Does this make sense?, anybody seen similar results?

> > >

> > > Kevin



----------------------------

#7439 Dec 26, 2001

One interesting thing that I noticed is that my G-11 acts VERY different loaded verses unloaded. If I remove my RA motor and turn the worm by hand there is significant binding if the mount in unloaded. If I add the counterweights and OTA the worm turns very smoothly. So, it makes sense to me that there would be a point where a *lighter* load could actually result in poorer tracking regardless of correct balance.



Frank

www.my-spot.com ----- Original Message -----

From: bizman2001

To: Losmandy_users@yahoogroups.com

Sent: Monday, December 24, 2001 12:15 PM

Subject: [Losmandy_users] Improved G11 performance Seen





I noted something recently that may be of interest. I have been using

the G11 for a couple years now. When first recieved I was using a

C11 on it and I measured only about 6" or so PE uncorrected.



Then recently have been working with a C8 and CCD, and have been

battling some tracking issues. Just track and accumulate as I have

not autoguider. I had even noted in here before problems with light

breezes. I recenlty added a guidescope which with all losmandy

mounting hardware such as addtional dovetail, dovetail adapters rings

and scope, 2" diag, ep and camera add a significant amount of weight

which required the 21 lb weight to be put back on.



When doing some guided photos, I noticed I hardly had to make any

corrections over 10 minutes. It was tracking like a dream, kind of

like the C11 did. This may be due to balance. I have noted with CCD

results that the mount tracks better perfectly balanced rather than

rule of thumb weighting to east. But with 11 lb weight and C8 alone,

balance is tough to judge as there is some inherant friction in mount

so you can slide weight back and forth a fair amount and it won't

move one way or another. But higher instrument load and 21lb weight,

there is little guess where balance is.



Does this make sense?, anybody seen similar results?



Kevin





Yahoo! Groups Sponsor

ADVERTISEMENT









To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.







[Non-text portions of this message have been removed]







----------------------------

#7441 Dec 26, 2001

Frank,

Couldn't this binding be the result of not be able to balance the ra axis without the OTA and counterweights?



Rober



< lists@... 12/26 11:26a >>>

One interesting thing that I noticed is that my G-11 acts VERY different loaded verses unloaded. If I remove my RA motor and turn the worm by hand there is significant binding if the mount in unloaded. If I add the counterweights and OTA the worm turns very smoothly. So, it makes sense to me that there would be a point where a *lighter* load could actually result in poorer tracking regardless of correct balance.



Frank

www.my-spot.com ----- Original Message -----

From: bizman2001

To: Losmandy_users@yahoogroups.com

Sent: Monday, December 24, 2001 12:15 PM

Subject: [Losmandy_users] Improved G11 performance Seen





I noted something recently that may be of interest. I have been using

the G11 for a couple years now. When first recieved I was using a

C11 on it and I measured only about 6" or so PE uncorrected.



Then recently have been working with a C8 and CCD, and have been

battling some tracking issues. Just track and accumulate as I have

not autoguider. I had even noted in here before problems with light

breezes. I recenlty added a guidescope which with all losmandy

mounting hardware such as addtional dovetail, dovetail adapters rings

and scope, 2" diag, ep and camera add a significant amount of weight

which required the 21 lb weight to be put back on.



When doing some guided photos, I noticed I hardly had to make any

corrections over 10 minutes. It was tracking like a dream, kind of

like the C11 did. This may be due to balance. I have noted with CCD

results that the mount tracks better perfectly balanced rather than

rule of thumb weighting to east. But with 11 lb weight and C8 alone,

balance is tough to judge as there is some inherant friction in mount

so you can slide weight back and forth a fair amount and it won't

move one way or another. But higher instrument load and 21lb weight,

there is little guess where balance is.



Does this make sense?, anybody seen similar results?



Kevin





Yahoo! Groups Sponsor

ADVERTISEMENT









To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.







[Non-text portions of this message have been removed]







To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/



----------------------------

#7445 Dec 26, 2001

Maybe, but I think the all the weight compresses the thrust bearings under the worm wheel which "centers" the worm & wheel. If you have ever tried to take your G-11 apart, you should find that the worm wheel cannot easily be removed until the worm is at least loosened, the shape of the teeth on the wheel prevents the gear from moving up the RA axis. That means that the worm & wheel get "tighter" or "looser" as you change the position along the RA axis...



Frank

www.my-spot.com ----- Original Message -----

From: Robert Burns

To: Losmandy_users@yahoogroups.com

Sent: Wednesday, December 26, 2001 1:23 PM

Subject: Re: [Losmandy_users] Improved G11 performance Seen





Frank,

Couldn't this binding be the result of not be able to balance the ra axis without the OTA and counterweights?



Rober



< lists@... 12/26 11:26a >>>

One interesting thing that I noticed is that my G-11 acts VERY different loaded verses unloaded. If I remove my RA motor and turn the worm by hand there is significant binding if the mount in unloaded. If I add the counterweights and OTA the worm turns very smoothly. So, it makes sense to me that there would be a point where a *lighter* load could actually result in poorer tracking regardless of correct balance.



Frank

www.my-spot.com

----- Original Message -----

From: bizman2001

To: Losmandy_users@yahoogroups.com

Sent: Monday, December 24, 2001 12:15 PM

Subject: [Losmandy_users] Improved G11 performance Seen





I noted something recently that may be of interest. I have been using

the G11 for a couple years now. When first recieved I was using a

C11 on it and I measured only about 6" or so PE uncorrected.



Then recently have been working with a C8 and CCD, and have been

battling some tracking issues. Just track and accumulate as I have

not autoguider. I had even noted in here before problems with light

breezes. I recenlty added a guidescope which with all losmandy

mounting hardware such as addtional dovetail, dovetail adapters rings

and scope, 2" diag, ep and camera add a significant amount of weight

which required the 21 lb weight to be put back on.



When doing some guided photos, I noticed I hardly had to make any

corrections over 10 minutes. It was tracking like a dream, kind of

like the C11 did. This may be due to balance. I have noted with CCD

results that the mount tracks better perfectly balanced rather than

rule of thumb weighting to east. But with 11 lb weight and C8 alone,

balance is tough to judge as there is some inherant friction in mount

so you can slide weight back and forth a fair amount and it won't

move one way or another. But higher instrument load and 21lb weight,

there is little guess where balance is.



Does this make sense?, anybody seen similar results?



Kevin





Yahoo! Groups Sponsor

ADVERTISEMENT









To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.







[Non-text portions of this message have been removed]







To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/











Yahoo! Groups Sponsor

ADVERTISEMENT









To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.







[Non-text portions of this message have been removed]







----------------------------

#7990 Jan 17, 2002

Here's a blurb from the G11 manual:



"NOTE: The PEC does NOT have to be activated for the drive to work.

Once PEC is activated, however, you can only use .3x or .5x tracking

rate. You can not change to a faster rate until PEC is turned off."



I don't have an autoguider, and I'd like to make longer exposures so

can I set PEC and then turn PEC off as I center a subject? I'll be

glad to turn it back on when the object is centered. I have a sneaky

suspicion it won't work and that somebody on this group has tried.



Thanks for any advice you can give. (I know... buy an autoguider)



Shane LaPierre

www.geocities.com/stellar1972



----------------------------

#7991 Jan 17, 2002

Shane,



You're correct about that. What I do is I actually start my exposure during

initial PEC training.....saves me time. Just have to be extra vigilant and

have my eye glued on the guiding ep for the first 4 minutes. After that,

it's smooth sailing.



George



----------------------------

#7992 Jan 17, 2002

I was just at the Losmandy web site and notice something that I

had never realized before. Under the features of the Gemini unit is

listed "permanent periodic error correction". I think the pre-Gemini

units had PEC but it was not permanent. I didn't think the Gemini

units had permanent PEC either, but perhaps I'm wrong. Does anyone

have any additional info on the permanent part? Am I just way behind

the times?



Ron Saunders --- In Losmandy_users@y..., "stellar1972" shanelapierre@h...> wrote:

> Here's a blurb from the G11 manual:

>

> "NOTE: The PEC does NOT have to be activated for the drive to work.

> Once PEC is activated, however, you can only use .3x or .5x tracking

> rate. You can not change to a faster rate until PEC is turned off."

>

> I don't have an autoguider, and I'd like to make longer exposures so

> can I set PEC and then turn PEC off as I center a subject? I'll be

> glad to turn it back on when the object is centered. I have a

sneaky

> suspicion it won't work and that somebody on this group has tried.

>

> Thanks for any advice you can give. (I know... buy an autoguider)

>

> Shane LaPierre

> www.geocities.com/stellar1972



----------------------------

#7993 Jan 17, 2002

The older Losmandy digital drive system did indeed not have permanent PEC.

In fact it was ridiculously temporary, verging on unuseable. Unless you

liked re-training it every time you turn it on, which I believe most people

don't.



This wouldn't have been so bad if you still had all of the fast slew rates

available after PEC training, but typically you would not train Pec after

your target was centered. rather you would train PEC on a suitable star then

you would want to center your target, except you only had the two slowest

guide modes available. Turn PEC off to slew normally and training is lost!



The Gemini fills the gap now though. Although I don't have a Gemini I

believe it does have a permanent PEC. Once trained it is always available

even after powering down and up again.



Thanks,



Eddie Trimarchi

~~~~~~~~~~~~~~~

users.bigpond.net.au/eddiet



-----Original Message-----

From: saunders_ron [mailto:ron@...]

Sent: Friday, 18 January 2002 7:54 AM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: G11 PEC & tracking





I was just at the Losmandy web site and notice something that I

had never realized before. Under the features of the Gemini unit is

listed "permanent periodic error correction". I think the pre-Gemini

units had PEC but it was not permanent. I didn't think the Gemini

units had permanent PEC either, but perhaps I'm wrong. Does anyone

have any additional info on the permanent part? Am I just way behind

the times?



Ron Saunders --- In Losmandy_users@y..., "stellar1972" shanelapierre@h...> wrote:

> Here's a blurb from the G11 manual:

>

> "NOTE: The PEC does NOT have to be activated for the drive to work.

> Once PEC is activated, however, you can only use .3x or .5x tracking

> rate. You can not change to a faster rate until PEC is turned off."

>

> I don't have an autoguider, and I'd like to make longer exposures so

> can I set PEC and then turn PEC off as I center a subject? I'll be

> glad to turn it back on when the object is centered. I have a

sneaky

> suspicion it won't work and that somebody on this group has tried.

>

> Thanks for any advice you can give. (I know... buy an autoguider)

>

> Shane LaPierre

> www.geocities.com/stellar1972







To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/



----------------------------

#7994 Jan 17, 2002

Once PEC is turned off, it has to be retrained when turned back on.



Mike Leitch

galaxy@...

Astrophotography website

www.ncweb.com/~galaxy/home/astropho.htm ----- Original Message -----

From: stellar1972 shanelapierre@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, January 17, 2002 3:13 PM

Subject: [Losmandy_users] G11 PEC & tracking





> Here's a blurb from the G11 manual:

>

> "NOTE: The PEC does NOT have to be activated for the drive to work.

> Once PEC is activated, however, you can only use .3x or .5x tracking

> rate. You can not change to a faster rate until PEC is turned off."

>

> I don't have an autoguider, and I'd like to make longer exposures so

> can I set PEC and then turn PEC off as I center a subject? I'll be

> glad to turn it back on when the object is centered. I have a sneaky

> suspicion it won't work and that somebody on this group has tried.

>

> Thanks for any advice you can give. (I know... buy an autoguider)

>

> Shane LaPierre

> www.geocities.com/stellar1972

>

>

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com

>

>

>

> Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/

>

>







----------------------------

#8001 Jan 17, 2002

Hi Eddie,

Let me get this straight;

After training PEC on a standard G11, if I turn it off, (say, to slew

the scope), its memory is erased? I was under the impression this

only happened when the mount was powered down.

-Topher Allan --- In Losmandy_users@y..., "Eddie Trimarchi" eddiet@b...> wrote:

> The older Losmandy digital drive system did indeed not have

permanent PEC.

> In fact it was ridiculously temporary, verging on unuseable. Unless

you

> liked re-training it every time you turn it on, which I believe

most people

> don't.

>

> This wouldn't have been so bad if you still had all of the fast

slew rates

> available after PEC training, but typically you would not train Pec

after

> your target was centered. rather you would train PEC on a suitable

star then

> you would want to center your target, except you only had the two

slowest

> guide modes available. Turn PEC off to slew normally and training

is lost!

>

> The Gemini fills the gap now though. Although I don't have a Gemini

I

> believe it does have a permanent PEC. Once trained it is always

available

> even after powering down and up again.

>

> Thanks,

>

> Eddie Trimarchi

> ~~~~~~~~~~~~~~~

> users.bigpond.net.au/eddiet

>

> -----Original Message-----

> From: saunders_ron [mailto:ron@p...]

> Sent: Friday, 18 January 2002 7:54 AM

> To: Losmandy_users@y...

> Subject: [Losmandy_users] Re: G11 PEC & tracking

>

>

> I was just at the Losmandy web site and notice something that I

> had never realized before. Under the features of the Gemini unit is

> listed "permanent periodic error correction". I think the pre-

Gemini

> units had PEC but it was not permanent. I didn't think the Gemini

> units had permanent PEC either, but perhaps I'm wrong. Does anyone

> have any additional info on the permanent part? Am I just way

behind

> the times?

>

> Ron Saunders

> --- In Losmandy_users@y..., "stellar1972" shanelapierre@h...>

wrote:

> > Here's a blurb from the G11 manual:

> >

> > "NOTE: The PEC does NOT have to be activated for the drive to

work.

> > Once PEC is activated, however, you can only use .3x or .5x

tracking

> > rate. You can not change to a faster rate until PEC is turned

off."

> >

> > I don't have an autoguider, and I'd like to make longer exposures

so

> > can I set PEC and then turn PEC off as I center a subject? I'll

be

> > glad to turn it back on when the object is centered. I have a

> sneaky

> > suspicion it won't work and that somebody on this group has tried.

> >

> > Thanks for any advice you can give. (I know... buy an autoguider)

> >

> > Shane LaPierre

> > www.geocities.com/stellar1972

>

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@e...

>

>

>

> Your use of Yahoo! Groups is subject to

docs.yahoo.com/info/terms/



----------------------------

#8002 Jan 17, 2002

I believe you have it straight. Pec needs retraining after it (PEC, not the

drive controller) is turned off. Pretty useful don't you think?



Thanks,



Eddie Trimarchi

~~~~~~~~~~~~~~~

users.bigpond.net.au/eddiet



-----Original Message-----

From: tmallan [mailto:tmallan@...]

Sent: Friday, 18 January 2002 12:04 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: G11 PEC & tracking





Hi Eddie,

Let me get this straight;

After training PEC on a standard G11, if I turn it off, (say, to slew

the scope), its memory is erased? I was under the impression this

only happened when the mount was powered down.

-Topher Allan --- In Losmandy_users@y..., "Eddie Trimarchi" eddiet@b...> wrote:

> The older Losmandy digital drive system did indeed not have

permanent PEC.

> In fact it was ridiculously temporary, verging on unuseable. Unless

you

> liked re-training it every time you turn it on, which I believe

most people

> don't.

>

> This wouldn't have been so bad if you still had all of the fast

slew rates

> available after PEC training, but typically you would not train Pec

after

> your target was centered. rather you would train PEC on a suitable

star then

> you would want to center your target, except you only had the two

slowest

> guide modes available. Turn PEC off to slew normally and training

is lost!

>

> The Gemini fills the gap now though. Although I don't have a Gemini

I

> believe it does have a permanent PEC. Once trained it is always

available

> even after powering down and up again.

>

> Thanks,

>

> Eddie Trimarchi

> ~~~~~~~~~~~~~~~

> users.bigpond.net.au/eddiet

>

> -----Original Message-----

> From: saunders_ron [mailto:ron@p...]

> Sent: Friday, 18 January 2002 7:54 AM

> To: Losmandy_users@y...

> Subject: [Losmandy_users] Re: G11 PEC & tracking

>

>

> I was just at the Losmandy web site and notice something that I

> had never realized before. Under the features of the Gemini unit is

> listed "permanent periodic error correction". I think the pre-

Gemini

> units had PEC but it was not permanent. I didn't think the Gemini

> units had permanent PEC either, but perhaps I'm wrong. Does anyone

> have any additional info on the permanent part? Am I just way

behind

> the times?

>

> Ron Saunders

> --- In Losmandy_users@y..., "stellar1972" shanelapierre@h...>

wrote:

> > Here's a blurb from the G11 manual:

> >

> > "NOTE: The PEC does NOT have to be activated for the drive to

work.

> > Once PEC is activated, however, you can only use .3x or .5x

tracking

> > rate. You can not change to a faster rate until PEC is turned

off."

> >

> > I don't have an autoguider, and I'd like to make longer exposures

so

> > can I set PEC and then turn PEC off as I center a subject? I'll

be

> > glad to turn it back on when the object is centered. I have a

> sneaky

> > suspicion it won't work and that somebody on this group has tried.

> >

> > Thanks for any advice you can give. (I know... buy an autoguider)

> >

> > Shane LaPierre

> > www.geocities.com/stellar1972

>

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@e...

>

>

>

> Your use of Yahoo! Groups is subject to

docs.yahoo.com/info/terms/







To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/







----------------------------

#8008 Jan 18, 2002

Hi guys,

--- In Losmandy_users@y..., "Eddie Trimarchi" eddiet@b...> wrote:



"This wouldn't have been so bad if you still had all of the fast slew

rates available after PEC training, but typically you would not train

Pec after your target was centered. rather you would train PEC on a

suitable star then you would want to center your target, except you

only had the two slowest guide modes available. Turn PEC off to slew

normally and training is lost!"



Exactly, a real pain! . moreover with a GM8 training PEC means 8

minutes of boring careful guiding, not only 4 . but, quoting from

GM8 User's Manual:

" To move the telescope at the 16x speed WITHOUT changing the guide

setting, press the button that corresponds to the direction you want

to move the telescope. While holding the button down, press the

opposite directional button. For example, if you want to move the

telescope west, hold the west button down and then press the east

button. Conversely, if you want to move the telescopes east, hold the

east button down and then press the west button. Also, after two

seconds of the 16x rate, it will switch to 32x. This fast-set

function also works in declination."



Could this method be used to slew to the target while in "PEC on"

mode? Yes, I know, it could be a little too fast . I've never

tried .

someone has?



Thanks,



Marco



----------------------------

#8010 Jan 18, 2002

In a message dated 1/17/2002 9:09:39 PM Eastern Standard Time,

tmallan@... writes:

> After training PEC on a standard G11, if I turn it off, (say, to slew

> the scope), its memory is erased? I was under the impression this

> only happened when the mount was powered down.



Yes, whenever you TURN IT OFF (or power down) you lose the PEC.

Kinda a pain, but that's the way it is........



The PEC on my G 11 does seem to help some, so when I do the

long exposure photography, I will definitely use it...



Allan Mayer



----------------------------

#8023 Jan 18, 2002

Dear Members,



Unless I am completely out-to-lunch w.r.t. to how PEC

works, you do not want to EVER slew your scope at a

fast rate after PEC training. Otherwise the PEC training

is no longer good anyway.



PEC training "teaches" your drive controller the

characteristics of your worm gear w.r.t. to its

rotational position. The starting rotational position is

where ever you begin training. From that point forward

you "teach" your drive controller what the PE of

your mount is w.r.t. to the starting rotational position.



If you slew your scope at a fast rate, then where

the worm gear's rotational position stops will not

likely be where the drive controller "thinks" it is.

As a result the drive controller will not make good

corrections.



That's why fast slewing is disabled after PEC training

and also why I have never understood the usefullness

of "persistent" PEC training.



About the best suggestion I have heard for PEC training

is to train during the first four minutes of your

exposure if you are guiding manually or to let your

autoguider train the PEC if you have one.



Maybe this explains why some people have seen PEC

make their PE worse? I have been able to reduce my

PE by as much as 50% in some cases after PEC training.



Regards,



----------------------------

#8025 Jan 18, 2002

Dear Members,



Maybe a better way to explain this is as follows.



When you PEC train the drive controller simply records

the magnitude of the corrections that you make in RA

and when you made them.



After PEC training the drive controller simply plays

back what it recorded.



If you slew the scope fast, then the drive controller

will be playing back what it recorded at the wrong

time.



Regards,

--- In Losmandy_users@y..., "cjl023" james.lacey@m...> wrote:

> Dear Members,

>

> Unless I am completely out-to-lunch w.r.t. to how PEC

> works, you do not want to EVER slew your scope at a

> fast rate after PEC training. Otherwise the PEC training

> is no longer good anyway.

>

> PEC training "teaches" your drive controller the

> characteristics of your worm gear w.r.t. to its

> rotational position. The starting rotational position is

> where ever you begin training. From that point forward

> you "teach" your drive controller what the PE of

> your mount is w.r.t. to the starting rotational position.

>

> If you slew your scope at a fast rate, then where

> the worm gear's rotational position stops will not

> likely be where the drive controller "thinks" it is.

> As a result the drive controller will not make good

> corrections.

>

> That's why fast slewing is disabled after PEC training

> and also why I have never understood the usefullness

> of "persistent" PEC training.

>

> About the best suggestion I have heard for PEC training

> is to train during the first four minutes of your

> exposure if you are guiding manually or to let your

> autoguider train the PEC if you have one.

>

> Maybe this explains why some people have seen PEC

> make their PE worse? I have been able to reduce my

> PE by as much as 50% in some cases after PEC training.

>

> Regards,







----------------------------

#8027 Jan 18, 2002

James,

You might be right about how the PEC implementation in the digital drive

system works I really don't know, but every other system I have seen does

*not* stop you from high speed slewing once PEC has been trained. They must

somehow keep track of the worm and relative PEC playback position regardless

of whether slewing has taken place or not.

>Unless I am completely out-to-lunch w.r.t. to how PEC

>works, you do not want to EVER slew your scope at a

>fast rate after PEC training. Otherwise the PEC training

>is no longer good anyway.



Only in the simplest of PEC implementations. High speed slewing after PEC

training does exist and it's not difficult to imagine how this would be

done. Current PEC playback position, PEC resolution, motor step size and

slew rates are all known quantities. About the only thing I can see that

would mess this calculation up would be the coupling of the motor-to-worm.

Not knowning the PEC data resolution offhand, I am assuming that a

significant coupling glitch would be required to throw them out of sync.

>About the best suggestion I have heard for PEC training

>is to train during the first four minutes of your

>exposure if you are guiding manually or to let your

>autoguider train the PEC if you have one.



Actually, since I started autoguiding, I don't bother training PEC anymore.

The autoguider takes care of the corrections so PEC is pretty-much

redundant.

>Maybe this explains why some people have seen PEC

>make their PE worse? I have been able to reduce my

>PE by as much as 50% in some cases after PEC training.



Back when I was using the Sky Sensor 2000 and GPDX, I used single PEC

trainings for months (literally) and acheived 2.5" tracking accuracy for

unguided imaging the whole time. Permanent PEC (when it works) is a great

thing for unguided imaging and to simplify manual guiding, but not real

useful when autoguiding.



Thanks,



Eddie Trimarchi

~~~~~~~~~~~~~~~

users.bigpond.net.au/eddiet



-----Original Message-----

From: cjl023 [mailto:james.lacey@...]

Sent: Saturday, 19 January 2002 10:04 AM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: G11 PEC & tracking





Dear Members,



Unless I am completely out-to-lunch w.r.t. to how PEC

works, you do not want to EVER slew your scope at a

fast rate after PEC training. Otherwise the PEC training

is no longer good anyway.



PEC training "teaches" your drive controller the

characteristics of your worm gear w.r.t. to its

rotational position. The starting rotational position is

where ever you begin training. From that point forward

you "teach" your drive controller what the PE of

your mount is w.r.t. to the starting rotational position.



If you slew your scope at a fast rate, then where

the worm gear's rotational position stops will not

likely be where the drive controller "thinks" it is.

As a result the drive controller will not make good

corrections.



That's why fast slewing is disabled after PEC training

and also why I have never understood the usefullness

of "persistent" PEC training.



About the best suggestion I have heard for PEC training

is to train during the first four minutes of your

exposure if you are guiding manually or to let your

autoguider train the PEC if you have one.



Maybe this explains why some people have seen PEC

make their PE worse? I have been able to reduce my

PE by as much as 50% in some cases after PEC training.



Regards,









To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/



----------------------------

#8035 Jan 19, 2002

Mr. Trimarchi,



I agree with you. It seems that a sufficently sophisticated

drive controller would be able to keep up with how much

the worm has been rotated at fast slew rates, and then

adjust corrections accordingly.



We've seen though that the G-11 controller cannot even

handle simultaneous corrections to RA and DEC. Probably

there is not much hope for a better PEC function either.



Regards,



--- In Losmandy_users@y..., "Eddie Trimarchi" eddiet@b...> wrote:

> James,

> You might be right about how the PEC implementation in the digital

drive

> system works I really don't know, but every other system I have seen

does

> *not* stop you from high speed slewing once PEC has been trained.

They must

> somehow keep track of the worm and relative PEC playback position

regardless

> of whether slewing has taken place or not.

>

> >Unless I am completely out-to-lunch w.r.t. to how PEC

> >works, you do not want to EVER slew your scope at a

> >fast rate after PEC training. Otherwise the PEC training

> >is no longer good anyway.

>

> Only in the simplest of PEC implementations. High speed slewing

after PEC

> training does exist and it's not difficult to imagine how this would

be

> done. Current PEC playback position, PEC resolution, motor step size

and

> slew rates are all known quantities. About the only thing I can see

that

> would mess this calculation up would be the coupling of the

motor-to-worm.

> Not knowning the PEC data resolution offhand, I am assuming that a

> significant coupling glitch would be required to throw them out of

sync.

>

> >About the best suggestion I have heard for PEC training

> >is to train during the first four minutes of your

> >exposure if you are guiding manually or to let your

> >autoguider train the PEC if you have one.

>

> Actually, since I started autoguiding, I don't bother training PEC

anymore.

> The autoguider takes care of the corrections so PEC is pretty-much

> redundant.

>

> >Maybe this explains why some people have seen PEC

> >make their PE worse? I have been able to reduce my

> >PE by as much as 50% in some cases after PEC training.

>

> Back when I was using the Sky Sensor 2000 and GPDX, I used single

PEC

> trainings for months (literally) and acheived 2.5" tracking accuracy

for

> unguided imaging the whole time. Permanent PEC (when it works) is a

great

> thing for unguided imaging and to simplify manual guiding, but not

real

> useful when autoguiding.

>

> Thanks,

>

> Eddie Trimarchi

> ~~~~~~~~~~~~~~~

> users.bigpond.net.au/eddiet

>

> -----Original Message-----

> From: cjl023 [mailto:james.lacey@m...]

> Sent: Saturday, 19 January 2002 10:04 AM

> To: Losmandy_users@y...

> Subject: [Losmandy_users] Re: G11 PEC & tracking

>

>

> Dear Members,

>

> Unless I am completely out-to-lunch w.r.t. to how PEC

> works, you do not want to EVER slew your scope at a

> fast rate after PEC training. Otherwise the PEC training

> is no longer good anyway.

>

> PEC training "teaches" your drive controller the

> characteristics of your worm gear w.r.t. to its

> rotational position. The starting rotational position is

> where ever you begin training. From that point forward

> you "teach" your drive controller what the PE of

> your mount is w.r.t. to the starting rotational position.

>

> If you slew your scope at a fast rate, then where

> the worm gear's rotational position stops will not

> likely be where the drive controller "thinks" it is.

> As a result the drive controller will not make good

> corrections.

>

> That's why fast slewing is disabled after PEC training

> and also why I have never understood the usefullness

> of "persistent" PEC training.

>

> About the best suggestion I have heard for PEC training

> is to train during the first four minutes of your

> exposure if you are guiding manually or to let your

> autoguider train the PEC if you have one.

>

> Maybe this explains why some people have seen PEC

> make their PE worse? I have been able to reduce my

> PE by as much as 50% in some cases after PEC training.

>

> Regards,

>

>

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@e...

>

>

>

> Your use of Yahoo! Groups is subject to

docs.yahoo.com/info/terms/







----------------------------

#8038 Jan 19, 2002

--- In Losmandy_users@y..., "cjl023" james.lacey@m...> wrote: > Dear Members,

>

> Unless I am completely out-to-lunch w.r.t. to how PEC

> works, you do not want to EVER slew your scope at a

> fast rate after PEC training. Otherwise the PEC training

> is no longer good anyway.

>

> PEC training "teaches" your drive controller the

> characteristics of your worm gear w.r.t. to its

> rotational position. The starting rotational position is

> where ever you begin training. From that point forward

> you "teach" your drive controller what the PE of

> your mount is w.r.t. to the starting rotational position.

Whoa.

Even if you slew quickly, the controller (unless GoTo, is going to

fail as well), 'knows' where the output gear is, and where the

encoded motor drive is. Since the encoded motor, drives the worm, it

also knows where the worm itself is. PEC, falls into a series of

parts. The first (and largest), relates to where on the worm rotation

you are. Then you have smaller errors for the rotations of all teh

earlier gears, and other errors for the rotation of the output gear

itself. It is the worm's periodic error that is being corrected for,

and the position of this shaft in it's rotation is 'known', relative

to the original starting position, so long as the scope knows where

it is pointed...

> If you slew your scope at a fast rate, then where

> the worm gear's rotational position stops will not

> likely be where the drive controller "thinks" it is.

> As a result the drive controller will not make good

> corrections.

The worm'd position _is_ known. There will be error, because you are

now at a different part of the output gear, but the worm's error can

still be corrected for.

> That's why fast slewing is disabled after PEC training

> and also why I have never understood the usefullness

> of "persistent" PEC training.

On scopes like the LX200, there is a shaft position sensor, that

allows the same 'starting' position to be repeatably found. Given

this, the same PEC function can then be applied.

> About the best suggestion I have heard for PEC training

> is to train during the first four minutes of your

> exposure if you are guiding manually or to let your

> autoguider train the PEC if you have one.

>

> Maybe this explains why some people have seen PEC

> make their PE worse? I have been able to reduce my

> PE by as much as 50% in some cases after PEC training.

More probably, they are tending to pick up atmospheric noise as much

as 'periodic' error.



Best Wishes



----------------------------

#8078 Jan 21, 2002

James wrote: > That's why fast slewing is disabled after PEC training

> and also why I have never understood the usefullness

> of "persistent" PEC training.



Persistent PEC is usually only available in scopes that have encoders integrated with the motors/gears. This allows the PEC to be linked to a specific worm gear position, and be completely repeatable even after slewing, turning the scope off, etc. Since the non-GOTO G-11 PEC is simply time based (one worm cycle), it can't do that, as any repositioning of the mount with regard to the worm's position renders the PEC meaningless.



Persistent PEC is VERY nice. On my LX200, I could train it once using an autoguider, and never have to deal with it again. A good training would get the PE on the scope down from the 17 arc-secs or so it had "out of the box" to about 9 arc-secs, and it was nice, smooth, auto-guidable PE that was left...I used the same training session on the persistent PEC on the LX200 for over a year :)



Paul



----------------------------

#8081 Jan 21, 2002

I can see now why persistent PEC would be useful.



I never used it on my old LX200. Was not into imaging

as much as I am now.



I tried using the PEC on the G-11 last night while just

playing around with different techniques.



I was able to reduce the PE by quite a bit, but not being able

to slew at 16X made it a major pain to then try and center

an object (wasn't taking photos - just playing around).



The .3X and .5X are simply to slow to center with and moving

the scope only a few arc-minutes by hand is very difficult.



I tried manually guiding and trained the PEC on my guide star

for four minutes before beginning to "image" (not really -

like I said just playing around) and that seemed to work

reasonably well. I didn't get a chance to try and let my

autoguider "train" the PEC. Maybe 2night.



Regards,



-----Original Message-----

From: Paul LeFevre [mailto:lefevre@...]

Sent: Monday, January 21, 2002 10:20 AM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: G11 PEC & tracking





James wrote: > That's why fast slewing is disabled after PEC training

> and also why I have never understood the usefullness

> of "persistent" PEC training.



Persistent PEC is usually only available in scopes that have encoders

integrated with the motors/gears. This allows the PEC to be linked to a

specific worm gear position, and be completely repeatable even after

slewing, turning the scope off, etc. Since the non-GOTO G-11 PEC is simply

time based (one worm cycle), it can't do that, as any repositioning of the

mount with regard to the worm's position renders the PEC meaningless.



Persistent PEC is VERY nice. On my LX200, I could train it once using an

autoguider, and never have to deal with it again. A good training would get

the PE on the scope down from the 17 arc-secs or so it had "out of the box"

to about 9 arc-secs, and it was nice, smooth, auto-guidable PE that was

left...I used the same training session on the persistent PEC on the LX200

for over a year :)



Paul









To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/







----------------------------

#9933 Apr 25, 2002

I have been trying to gather data on my G11's PE.

I recorded the star coordinate output from my STV

every 2 seconds. The curious thing though, is that

I ended up with a cycle of 110 entries? 220 seconds?



Is this possibly a correct result?

I had always read the cycle was 4 minutes?



I was measuring bottom to bottom of a particulary

nasty dropp off. With an hours worth of data, the

dropoff occured at an average of 110 data points.



thanks, jim



----------------------------

#15233 May 12, 2003

Okay, I've measured the PE on my G11. You can see a graph of it here:



celestialwonders.com/FrankBG11PE.jpg



The data was collected over a period of about 14 minutes. The

average peak to peak PE is about 9.3" The unguided images I posted

last week had me thinking this would be somewhat less. I think I

have this resolved but I sure would like someone to confirm my math.

Some things to consider: I was imaging with the f/3.3 focal reducer

which would yeild about 2.8 arcsecs per pixel on my setup so PE error

would be about 3.3 pixels. Also I was imaging at high dec (M51 is +47

degress) so am I right that RA drift due to PE would be less than on

the celestial equator (which is where I took the measurement)? Any

math wiz out there can tell me the way to calculate this for a given

dec?



It's hard to argue with results, but with a PE of 9 arcsecs it just

seems like I should be seeing some drift...but I'm glad I didn't :)

I just feel like I'm missing something...



Frank

celestialwonders.com



----------------------------

#15238 May 12, 2003

Since the hand paddle becomes progressively more useless in RA as you

get to the pole, I would have to think that periodic error would

become less noticeable.



There is a trigonometric conversion of RA degrees to dec degrees

(which are standard degrees of arc) that my friend Pete posted to the

ARgo Navis group but I'm afraid I haven't memorized it.



By the way, imaging friends: NGC 2300 and NGC 2276 are a very nice

pair of galaxies, only five degrees from the N pole, and if any of

you photographs them I'd love to see the result. I have observed

visually but the only pics I've seen are off the DSS. NGC 2276 is a

nice spiral with a detached arm that should make for good detail.

Part of the imaging challenge isthat it is near a mag 7 star.



regards,

Greg Nowell







--- In Losmandy_users@yahoogroups.com, "Frank Barrett"

frankb02@b...> wrote: > Okay, I've measured the PE on my G11. You can see a graph of it

here: >

> celestialwonders.com/FrankBG11PE.jpg

>

> The data was collected over a period of about 14 minutes. The

> average peak to peak PE is about 9.3" The unguided images I posted

> last week had me thinking this would be somewhat less. I think I

> have this resolved but I sure would like someone to confirm my

math. > Some things to consider: I was imaging with the f/3.3 focal reducer

> which would yeild about 2.8 arcsecs per pixel on my setup so PE

error > would be about 3.3 pixels. Also I was imaging at high dec (M51 is

+47 > degress) so am I right that RA drift due to PE would be less than

on > the celestial equator (which is where I took the measurement)? Any

> math wiz out there can tell me the way to calculate this for a

given > dec?

>

> It's hard to argue with results, but with a PE of 9 arcsecs it just

> seems like I should be seeing some drift...but I'm glad I

didn't :) > I just feel like I'm missing something...

>

> Frank

> celestialwonders.com



----------------------------

#15239 May 12, 2003

----- Original Message -----

From: "gnowellsct"





> By the way, imaging friends: NGC 2300 and NGC 2276 are a very nice

> pair of galaxies, only five degrees from the N pole, and if any of

> you photographs them I'd love to see the result. I have observed

> visually but the only pics I've seen are off the DSS. NGC 2276 is a

> nice spiral with a detached arm that should make for good detail.

> Part of the imaging challenge isthat it is near a mag 7 star.



Greg,



This from the Arp page at

www.angelfire.com/id/jsredshift/peculwin.htm



"25 and 114 - NGCs 2276 and 2300 - 2276 m11.4 sb 13.2 2.6'x2.3' Sab/p - 2300

m11 sb 13.2 3.2'x2.8' SO-a 7h32m +85.43'. NGC 2276 is all of Arp 25 and

included in Arp 114 with NGC 2300. Arp Classification - Arp 25 - Spiral

galaxy with one heavy arm - Arp 114 - E-like galaxy close to and perturbing

spiral. With these two you get two Arps for the price of one. The

challenging part of this is that there is a mag 7.8 star only 1.7' W of NGC

2276. This makes 2276 hard to see at moderate powers. In the 16" at 233x it

was only visible using averted vision as a dim 2' diameter object with an

off-centered nucleus. It did not really start to shine until the

magnification was cranked up to 423x in the 20" and the star was moved out

of the field. Then the filamentary structure of its arms became obvious,

with a single arm on the S side of the galaxy standing out due to its

isolation. The north side of the core is a tangled thicket of several arms

and arm segments. NGC 2300 is located 6.5' ESE of 2276. It appeared pretty

much the same in both scopes, a round 2' diameter galaxy with a bright

non-stellar core. "



A two arc-minute object is going to be pretty small on a normal ccd chip

g>. I did find one photo: www.deep-sky.co.uk/galaxies/arp/arp114.jpg

that was taken through a 16" scope.



Jim Girard







----------------------------

#15241 May 12, 2003

By the way, imaging friends: NGC 2300 and NGC 2276 are a very nice

> pair of galaxies, only five degrees from the N pole, and if any of

> you photographs them I'd love to see the result. I have observed

> visually but the only pics I've seen are off the DSS. NGC 2276 is

a > nice spiral with a detached arm that should make for good detail.

> Part of the imaging challenge isthat it is near a mag 7 star.

>

> regards,

> Greg Nowell



If you don't mind a monochrome image, I'm game...and your in

luck...it's looking like clear skies tonight and I'm eager to try

something new. Thanks for the suggested target. Also this area

looks sufficiently far enough away from the 11 day gibbous moon.

I haven't tried imaging in this area of the sky due mostly to trees

(I have a small "hole" that I can use to polar align w/the PAS), so

I may have to find a new site. Being so close to the pole, one

should be able to go for long integrations unguided! I'm tempted to

try this at f/10 and see how it goes. According to Cartes du Ciel I

should be able to get both galaxies on the chip.



Can I share appropriate blame with you when I drag my sorry

unproductive butt into work late tommorrow g>?



Frank

celestialwonders.com



----------------------------

#15242 May 12, 2003

I'll be pleased to see it. The Dss pics are black on white

background. Not the most pleasing. Maybe you'll get inspired to do

a color version, or inspire someone else, too. This is great, thank

you. greg nowell



--- In Losmandy_users@yahoogroups.com, "Frank Barrett"

frankb02@b...> wrote: > > By the way, imaging friends: NGC 2300 and NGC 2276 are a very

nice > > pair of galaxies, only five degrees from the N pole, and if any

of > > you photographs them I'd love to see the result. I have observed

> > visually but the only pics I've seen are off the DSS. NGC 2276 is

> a

> > nice spiral with a detached arm that should make for good detail.

> > Part of the imaging challenge isthat it is near a mag 7 star.

> >

> > regards,

> > Greg Nowell

>

> If you don't mind a monochrome image, I'm game...and your in

> luck...it's looking like clear skies tonight and I'm eager to try

> something new. Thanks for the suggested target. Also this area

> looks sufficiently far enough away from the 11 day gibbous moon.

> I haven't tried imaging in this area of the sky due mostly to trees

> (I have a small "hole" that I can use to polar align w/the PAS), so

> I may have to find a new site. Being so close to the pole, one

> should be able to go for long integrations unguided! I'm tempted

to > try this at f/10 and see how it goes. According to Cartes du Ciel

I > should be able to get both galaxies on the chip.

>

> Can I share appropriate blame with you when I drag my sorry

> unproductive butt into work late tommorrow g>?

>

> Frank

> celestialwonders.com



----------------------------

#15244 May 12, 2003

Well I don't know about htese guys who claim it's a hard object. It

was very easy in the C14, on two separate nights. Put it this way

I've looked at harder. I didn't feel that the mag 7.8

star "interfered" either. Made for rather a pretty combination.



One of my club members, one of the guys that I respect, also found it

fairly easy to see. So I'd like to claim special talents. And lord

knows the seein sux in our area. I don't know, there are a number of

repectable people that claim it is difficult. To me 2276 is pretty

obvious. regards, Greg Nowell







--- In Losmandy_users@yahoogroups.com, "Jim Girard" argojg@c...>

wrote: >

> ----- Original Message -----

> From: "gnowellsct"

>

>

> > By the way, imaging friends: NGC 2300 and NGC 2276 are a very nice

> > pair of galaxies, only five degrees from the N pole, and if any of

> > you photographs them I'd love to see the result. I have observed

> > visually but the only pics I've seen are off the DSS. NGC 2276 is

a > > nice spiral with a detached arm that should make for good detail.

> > Part of the imaging challenge isthat it is near a mag 7 star.

>

> Greg,

>

> This from the Arp page at

> www.angelfire.com/id/jsredshift/peculwin.htm

>

> "25 and 114 - NGCs 2276 and 2300 - 2276 m11.4 sb 13.2 2.6'x2.3'

Sab/p - 2300 > m11 sb 13.2 3.2'x2.8' SO-a 7h32m +85.43'. NGC 2276 is all of Arp 25

and > included in Arp 114 with NGC 2300. Arp Classification - Arp 25 -

Spiral > galaxy with one heavy arm - Arp 114 - E-like galaxy close to and

perturbing > spiral. With these two you get two Arps for the price of one. The

> challenging part of this is that there is a mag 7.8 star only 1.7'

W of NGC > 2276. This makes 2276 hard to see at moderate powers. In the 16" at

233x it > was only visible using averted vision as a dim 2' diameter object

with an > off-centered nucleus. It did not really start to shine until the

> magnification was cranked up to 423x in the 20" and the star was

moved out > of the field. Then the filamentary structure of its arms became

obvious, > with a single arm on the S side of the galaxy standing out due to

its > isolation. The north side of the core is a tangled thicket of

several arms > and arm segments. NGC 2300 is located 6.5' ESE of 2276. It appeared

pretty > much the same in both scopes, a round 2' diameter galaxy with a

bright > non-stellar core. "

>

> A two arc-minute object is going to be pretty small on a normal ccd

chip > g>. I did find one photo: www.deep-

sky.co.uk/galaxies/arp/arp114.jpg > that was taken through a 16" scope.

>

> Jim Girard







----------------------------

#15250 May 13, 2003

--- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@h...>

wrote: > Well I don't know about htese guys who claim it's a hard object.

It > was very easy in the C14, on two separate nights. Put it this way

> I've looked at harder. I didn't feel that the mag 7.8

> star "interfered" either. Made for rather a pretty combination.

>

> One of my club members, one of the guys that I respect, also found

it > fairly easy to see. So I'd like to claim special talents. And

lord > knows the seein sux in our area. I don't know, there are a number

of > repectable people that claim it is difficult. To me 2276 is

pretty > obvious. regards, Greg Nowell

>

My brother-in-law's son said he wants a scope big enough to see the

moon debris from all our landings there. I told him to get an even

bigger scope - I can see Richard Nixon's signature! g>

Art



----------------------------

#15261 May 13, 2003

I'll be pleased to see it. The Dss pics are black on white

> background. Not the most pleasing. Maybe you'll get inspired to

do > a color version, or inspire someone else, too. This is great,

thank > you. greg nowell



Inspiration is _not_ the problem, $$$ for the color filter wheel is

:(



Here ya go...Seeing wasn't the greatest and the image is a bit on

the soft side. This was 120 minutes of integration, 24 stacked 5

minute unguided exposures. C8 on a G11. I may give this a go again

on a night with better seeing.



celestialwonders.com/NGC2276.jpg



Frank

celestialwonders.com



----------------------------

#16930 Sep 4, 2003

Those are interesting graphs showing tracking error. I have a new

G-11 and will be developing the same data soon. My sense is that my

mount does not have huge errors, but that they are not smooth 4-minute

sine curves. I may have to do some worm adjusting. That's ok, I

never feel like a new toy is really mine until I've had it apart a bit.



Interesting that your PE graphs (if I am reading the x-axis scale

correctly as in seconds) do not seem to have a strong 4-minute period

to them. Not sure what that would mean.



Paul Schulte



----------------------------

#16941 Sep 5, 2003

Hi Joe,

> Try taking 0.5 sec images to build your chart then send it to

> Scott Losmandy

> so you can discuss it with him on the phone. The cause might pop

> out and be

> something simple he is familar with...joe :)



thanks for the advice, it's cloudy here, next clear night i give it a go!



Erik.



----------------------------

#16942 Sep 5, 2003

----- Original Message -----

From: "gnowellsct"

Subject: [Losmandy_users] Re: G11 periodic error with high precisionworm





> I don't do imaging, and havn't replaced the bearings myself, but I

> can tell you that bearing replacement has been a frequent topic of

> disucssion on this group (I'm referring to the bearings associated

> with the worm, the third bearing in RA and Dec axes is a different

> topic). Try the 2000-2001 years.



One of the several things that I upgraded on my older Celestron/G-11, after

the Gemini conversion, was the worm bearings in both RA and Dec. The

originals were pretty rough, and I ended up replacing them with Abec 7

stainless steel double shielded bearings. I got mine from Miniature

Precision Components in Santa Clara (www.mpcomponents.com) Part number was

the E1-9. I did notice a difference after replacing them, although I never

quantified it. Just to the touch, the new bearings were much smoother than

the original (1997 vintage) ones. Coupled with the new 'precision' worm, it

made a world of difference in the smoothness of the periodic error. Error

still existed, but I no longer had the issue of sharp spikes in tracking. It

was easy for the self-guiding camera (ST-8) to guide out. I don't know what

the current mounts are using for worm bearings, though. Scott may have

upgraded these as well.



I also added the third bearing to both axes referred to, but honestly

couldn't say whether or not they made much of a difference.



Jim Girard



----------------------------

#17036 Sep 9, 2003

----- Original Message -----

From: "sandmanchang"

Subject: Re: G11 periodic error with high precisionworm





> could you give me the source and part number of the third bearing

> that you installed?

>

> thanks,

>

> sandy



Sandy,



I tried sending this to you directly, but mail kept bouncing, so...



Check out www.astronerd.net/astronomy/g11Bearings/g11Bearings.html

for info on the part numbers for the third bearings (from McMaster Carr).

There's also info about replacing the worm bearings although I got the Abec

7's from MPC.



Jim Girard



----------------------------

#22034 Aug 20, 2004

I currently have a permanent pier setup on the deck in my backyard

where I use my Meade 2120 for observing. The telescope and fork mount

are brought outside each night that I observe, and then taken back

inside after each session. I am considering the purchase of the G11

to be able to better pursue digital astrophotography.



I was wondering what the experience of the group is with the G11 (or

G8) mount as far as permanent pier installations, especially in the

deep, humid south where I live. Is it safe to leave G11 mount

outdoors, suitably protected, or do most users bring it in after

every observing session?



If left outside, is suitable protecton considered a closed roof

observatory, or will something such as a desert storm cover provide

enough protection?



I guess I ask because with a precision mount such as the G11, it

would seem that leaving it setup after it was properly polar aligned

would be preferable to putting it on the pier and taking it off each

night. Or is it possible to do this and maintain a good polar

alignment each night?



Forgive me for my ignorance, but this would be my first venture into

a truly electronically controlled scope, and for the money paid I

would certainly want to care for it properly.



Thanks for your help,



Claude







----------------------------

#22041 Aug 21, 2004

Claude,



I've had my mount in a dome without temperature/humidity control this

Summer...in Florida. No ill effects noticed...in fact, it just survived

Hurricane Charley.



Every time we get rain some moisture collects on the floor of the dome, so

I have the scope/mount covered with an inexpensive tarp from Home Depot to

prevent it from having water fall directly on it and getting inside

something. I just draped it over the scope/mount to cover the OTA and

electronics...it is not gathered and tied at the bottom, allowing it to

breath. I typically take my refractor with me, so I can use it between

visits to the dome, but have left my SCT on the mount...after Charley, I've

now decided it would make more sense to take the SCT off the mount and put

it back in its case...more setup time to use my scope, but much safer during

hurricane season.



If you have an observatory, you'll be fine leaving everything set up.



If you don't, I would take the electronics off, taking them inside with

you, and cover the mount with a Desert Storm cover (you might have to

replace the cover annually, give-or-take, depending on how severe the

weather is in your area...still a lot cheaper than erecting an observatory).



If your pier is well constructed, polar alignment should hold between

sessions.



Forrest Egan

fegan@...

www.digitalastro.com





-----Original Message-----

From: cetialpha4 [mailto:cetialpha4@...]

Sent: Saturday, August 21, 2004 12:41 AM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] G11 Permanent Pier Mounting





I currently have a permanent pier setup on the deck in my backyard

where I use my Meade 2120 for observing. The telescope and fork mount

are brought outside each night that I observe, and then taken back

inside after each session. I am considering the purchase of the G11

to be able to better pursue digital astrophotography.



I was wondering what the experience of the group is with the G11 (or

G8) mount as far as permanent pier installations, especially in the

deep, humid south where I live. Is it safe to leave G11 mount

outdoors, suitably protected, or do most users bring it in after

every observing session?



If left outside, is suitable protecton considered a closed roof

observatory, or will something such as a desert storm cover provide

enough protection?



I guess I ask because with a precision mount such as the G11, it

would seem that leaving it setup after it was properly polar aligned

would be preferable to putting it on the pier and taking it off each

night. Or is it possible to do this and maintain a good polar

alignment each night?



Forgive me for my ignorance, but this would be my first venture into

a truly electronically controlled scope, and for the money paid I

would certainly want to care for it properly.



Thanks for your help,



Claude



----------------------------

#22044 Aug 21, 2004

Claude,



I have my G11/Gemini setup outside on a permanent pier. It's been on

it for the last three years, covered by an equivalent of a desert

storm cover. I do take the electronics inside most of the time,

unless I expect the weather to cooperate for a few nights in a row

(can't remember the last time this has happened ;-(



I'm located in the North East US and the weather here is extremely

humid in the summer, and pretty cold (as low as 0F) in the winter.



I've seen no ill effects on the mount. It is made of non-corrosive

materials, and appears to resist moisture well. Insects are another

matter, though :)



I do regrease the mount about once a year, and grease all threads,

screws, etc. that are exposed.



Regards,



-Paul



--- In Losmandy_users@yahoogroups.com, "cetialpha4" cetialpha4@y...>

wrote: > I currently have a permanent pier setup on the deck in my backyard

> where I use my Meade 2120 for observing. The telescope and fork

mount > are brought outside each night that I observe, and then taken back

> inside after each session. I am considering the purchase of the G11

> to be able to better pursue digital astrophotography.

>

> I was wondering what the experience of the group is with the G11

(or > G8) mount as far as permanent pier installations, especially in the

> deep, humid south where I live. Is it safe to leave G11 mount

> outdoors, suitably protected, or do most users bring it in after

> every observing session?

>

> If left outside, is suitable protecton considered a closed roof

> observatory, or will something such as a desert storm cover provide

> enough protection?

>

> I guess I ask because with a precision mount such as the G11, it

> would seem that leaving it setup after it was properly polar

aligned > would be preferable to putting it on the pier and taking it off

each > night. Or is it possible to do this and maintain a good polar

> alignment each night?

>

> Forgive me for my ignorance, but this would be my first venture

into > a truly electronically controlled scope, and for the money paid I

> would certainly want to care for it properly.

>

> Thanks for your help,

>

> Claude







----------------------------

#22045 Aug 21, 2004

Paul,



I'm guessing you take the optics in though, right? How does your alignment and pointing do--or do you re-build your model each time?



Take care,

Bob ----- Original Message -----

From: Paul K

To: Losmandy_users@yahoogroups.com

Sent: Saturday, August 21, 2004 11:41 AM

Subject: [Losmandy_users] Re: G11 Permanent Pier Mounting





Claude,



I have my G11/Gemini setup outside on a permanent pier. It's been on

it for the last three years, covered by an equivalent of a desert

storm cover. I do take the electronics inside most of the time,

unless I expect the weather to cooperate for a few nights in a row

(can't remember the last time this has happened ;-(



I'm located in the North East US and the weather here is extremely

humid in the summer, and pretty cold (as low as 0F) in the winter.



I've seen no ill effects on the mount. It is made of non-corrosive

materials, and appears to resist moisture well. Insects are another

matter, though :)



I do regrease the mount about once a year, and grease all threads,

screws, etc. that are exposed.



Regards,



-Paul



--- In Losmandy_users@yahoogroups.com, "cetialpha4" cetialpha4@y...>

wrote:

> I currently have a permanent pier setup on the deck in my backyard

> where I use my Meade 2120 for observing. The telescope and fork

mount

> are brought outside each night that I observe, and then taken back

> inside after each session. I am considering the purchase of the G11

> to be able to better pursue digital astrophotography.

>

> I was wondering what the experience of the group is with the G11

(or

> G8) mount as far as permanent pier installations, especially in the

> deep, humid south where I live. Is it safe to leave G11 mount

> outdoors, suitably protected, or do most users bring it in after

> every observing session?

>

> If left outside, is suitable protecton considered a closed roof

> observatory, or will something such as a desert storm cover provide

> enough protection?

>

> I guess I ask because with a precision mount such as the G11, it

> would seem that leaving it setup after it was properly polar

aligned

> would be preferable to putting it on the pier and taking it off

each

> night. Or is it possible to do this and maintain a good polar

> alignment each night?

>

> Forgive me for my ignorance, but this would be my first venture

into

> a truly electronically controlled scope, and for the money paid I

> would certainly want to care for it properly.

>

> Thanks for your help,

>

> Claude











Yahoo! Groups Links













[Non-text portions of this message have been removed]



----------------------------

#22048 Aug 21, 2004

Claude,



I have been using a G11 on a permanent pier for about a year now. I'm

located in Maine and we too have our share of humid weather. My G11

is housed in a roll-off roof observatory for protection, which also

allows the scope to be left in place.



Except for the occasional spider web the G11 shows no signs of wear or

weathering from the humidity or winter cold. It's operation has been

flawless even at 20 below zero in january.



I would expect that a weather-tight cover would work well to protect

your mount. And especially to allow you to keep your pointing model

and park position intact from session to session.



These two Gemini features work remarkably well in a permanent setup

with a good polar alignment and a dozen or more objects in the

pointing model. I am able to simply power on the mount after days of

inactivity and slew to any object without even doing a one star

alignment. This also makes finding planets during the day a snap.



Having the G11 permanently set up makes my startup time about 4

minutes: open roof, power up equipment, insert eyepiece or camera,

remove lens cover and begin.



If you're into imaging, you already know how particular you have to be

with setup and alignment, and how long it takes each night to get it

there. Keeping the G11 in place lets you spend *way* less time

setting up and way more time enjoying the sky.



If you can manage to find a way to keep your G11 in place permanently,

I highly recommend it!



Regards,

Wayne Krauth



ps. Here is a picture of my 6" AP and Pronto on the G11

www.maineskies.org/in-operation.jpg





--- In Losmandy_users@yahoogroups.com, "cetialpha4" cetialpha4@y...>

wrote: > I currently have a permanent pier setup on the deck in my backyard

> where I use my Meade 2120 for observing. The telescope and fork mount

> are brought outside each night that I observe, and then taken back

> inside after each session. I am considering the purchase of the G11

> to be able to better pursue digital astrophotography.

>

> I was wondering what the experience of the group is with the G11 (or

> G8) mount as far as permanent pier installations, especially in the

> deep, humid south where I live. Is it safe to leave G11 mount

> outdoors, suitably protected, or do most users bring it in after

> every observing session?

>

> If left outside, is suitable protecton considered a closed roof

> observatory, or will something such as a desert storm cover provide

> enough protection?

>

> I guess I ask because with a precision mount such as the G11, it

> would seem that leaving it setup after it was properly polar aligned

> would be preferable to putting it on the pier and taking it off each

> night. Or is it possible to do this and maintain a good polar

> alignment each night?

>

> Forgive me for my ignorance, but this would be my first venture into

> a truly electronically controlled scope, and for the money paid I

> would certainly want to care for it properly.

>

> Thanks for your help,

>

> Claude







----------------------------

#22054 Aug 21, 2004

Hi Bob,



Yes, I take the optics inside every time. I rebuild the model about

once very 2-3 months, which is also when I redo the polar alignment.

It seems to work well for the times in between.



Regards,



-Paul





--- In Losmandy_users@yahoogroups.com, "Bob Benamati"

bobbenamati@c...> wrote: > Paul,

>

> I'm guessing you take the optics in though, right? How does your

alignment and pointing do--or do you re-build your model each time? >

> Take care,

> Bob

> ----- Original Message -----

> From: Paul K

> To: Losmandy_users@yahoogroups.com

> Sent: Saturday, August 21, 2004 11:41 AM

> Subject: [Losmandy_users] Re: G11 Permanent Pier Mounting

>

>

> Claude,

>

> I have my G11/Gemini setup outside on a permanent pier. It's been

on > it for the last three years, covered by an equivalent of a desert

> storm cover. I do take the electronics inside most of the time,

> unless I expect the weather to cooperate for a few nights in a

row > (can't remember the last time this has happened ;-(

>

> I'm located in the North East US and the weather here is

extremely > humid in the summer, and pretty cold (as low as 0F) in the winter.

>

> I've seen no ill effects on the mount. It is made of non-

corrosive > materials, and appears to resist moisture well. Insects are

another > matter, though :)

>

> I do regrease the mount about once a year, and grease all

threads, > screws, etc. that are exposed.

>

> Regards,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "cetialpha4"

cetialpha4@y...> > wrote:

> > I currently have a permanent pier setup on the deck in my

backyard > > where I use my Meade 2120 for observing. The telescope and fork

> mount

> > are brought outside each night that I observe, and then taken

back > > inside after each session. I am considering the purchase of the

G11 > > to be able to better pursue digital astrophotography.

> >

> > I was wondering what the experience of the group is with the

G11 > (or

> > G8) mount as far as permanent pier installations, especially in

the > > deep, humid south where I live. Is it safe to leave G11 mount

> > outdoors, suitably protected, or do most users bring it in

after > > every observing session?

> >

> > If left outside, is suitable protecton considered a closed roof

> > observatory, or will something such as a desert storm cover

provide > > enough protection?

> >

> > I guess I ask because with a precision mount such as the G11,

it > > would seem that leaving it setup after it was properly polar

> aligned

> > would be preferable to putting it on the pier and taking it off

> each

> > night. Or is it possible to do this and maintain a good polar

> > alignment each night?

> >

> > Forgive me for my ignorance, but this would be my first venture

> into

> > a truly electronically controlled scope, and for the money paid

I > > would certainly want to care for it properly.

> >

> > Thanks for your help,

> >

> > Claude

>

>

>

>

>

> Yahoo! Groups Links

>

>

>

>

>

>

> [Non-text portions of this message have been removed]



----------------------------

#22056 Aug 21, 2004

Interesting! I'm planning on building a shed observatory once my pier comes in, and would feel much better if I'd take the FSQ or C11 in the house rather than to risk it in the weather..... You may have convinced me that I'd be better off doing just that!



Thanks,

Bob ----- Original Message -----

From: Paul K

To: Losmandy_users@yahoogroups.com

Sent: Saturday, August 21, 2004 8:25 PM

Subject: [Losmandy_users] Re: G11 Permanent Pier Mounting





Hi Bob,



Yes, I take the optics inside every time. I rebuild the model about

once very 2-3 months, which is also when I redo the polar alignment.

It seems to work well for the times in between.



Regards,



-Paul





--- In Losmandy_users@yahoogroups.com, "Bob Benamati"

bobbenamati@c...> wrote:

> Paul,

>

> I'm guessing you take the optics in though, right? How does your

alignment and pointing do--or do you re-build your model each time?

>

> Take care,

> Bob

> ----- Original Message -----

> From: Paul K

> To: Losmandy_users@yahoogroups.com

> Sent: Saturday, August 21, 2004 11:41 AM

> Subject: [Losmandy_users] Re: G11 Permanent Pier Mounting

>

>

> Claude,

>

> I have my G11/Gemini setup outside on a permanent pier. It's been

on

> it for the last three years, covered by an equivalent of a desert

> storm cover. I do take the electronics inside most of the time,

> unless I expect the weather to cooperate for a few nights in a

row

> (can't remember the last time this has happened ;-(

>

> I'm located in the North East US and the weather here is

extremely

> humid in the summer, and pretty cold (as low as 0F) in the winter.

>

> I've seen no ill effects on the mount. It is made of non-

corrosive

> materials, and appears to resist moisture well. Insects are

another

> matter, though :)

>

> I do regrease the mount about once a year, and grease all

threads,

> screws, etc. that are exposed.

>

> Regards,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "cetialpha4"

cetialpha4@y...>

> wrote:

> > I currently have a permanent pier setup on the deck in my

backyard

> > where I use my Meade 2120 for observing. The telescope and fork

> mount

> > are brought outside each night that I observe, and then taken

back

> > inside after each session. I am considering the purchase of the

G11

> > to be able to better pursue digital astrophotography.

> >

> > I was wondering what the experience of the group is with the

G11

> (or

> > G8) mount as far as permanent pier installations, especially in

the

> > deep, humid south where I live. Is it safe to leave G11 mount

> > outdoors, suitably protected, or do most users bring it in

after

> > every observing session?

> >

> > If left outside, is suitable protecton considered a closed roof

> > observatory, or will something such as a desert storm cover

provide

> > enough protection?

> >

> > I guess I ask because with a precision mount such as the G11,

it

> > would seem that leaving it setup after it was properly polar

> aligned

> > would be preferable to putting it on the pier and taking it off

> each

> > night. Or is it possible to do this and maintain a good polar

> > alignment each night?

> >

> > Forgive me for my ignorance, but this would be my first venture

> into

> > a truly electronically controlled scope, and for the money paid

I

> > would certainly want to care for it properly.

> >

> > Thanks for your help,

> >

> > Claude

>

>

>

>

>

> Yahoo! Groups Links

>

>

>

>

>

>

> [Non-text portions of this message have been removed]











Yahoo! Groups Links













[Non-text portions of this message have been removed]







----------------------------

#26450 Jul 21, 2005

Hi All



I have recently bought a new G11 with Gemini. Although the stand is

wonderful for visual use, I have been very dissappointed with the

PE. The amplitude is quite reasonable, but the curve is anything but

smooth. I have uploaded the PE to the files section (G11 PE help

needed.xls)



The telescope was carefuly balanced with a slight bias to the east. I

have adjusted the gearbox and left worm block positions to try and

minimise the offset between the worm shaft and the gearbox shaft. The

right worm block has been adjusted to allow some backlash. It

is now possible to rotate the worm without the hinges of the Oldham

coupler moving up and down (it was over 0.5mm out both horizontaly

and verticaly). This has improved the PE but as you can see it still

has a large random element to it and this makes it too rough.



I assume that the worm is always at a tangent to the main wheel -

adjusting the angle of the worm would just move the contact point

left or right along the worm.



Of course the worm might not be in the plane of the wheel - anyone

know how I could check for this?



Any ideas on what the problem might be?



Thanks

John Murphy



----------------------------

#26451 Jul 21, 2005

Hi John,



For best performance in a G11, the motor shaft, oldham coupler and

the worm should be in as straight a line as possible. Furthermore,

because the worm is decoupled from the motor, it is important to

have the worm blocks equidistant from the gear cover. This helps

make the worm as parallel to the motor shaft as possible.



To accomplish this, use automotive feeler gauges to measure the

distance between the worm blocks and the gear cover. These should be

very nearly the same.



Another important adjustment is the worm float between the two worm

posts. It is important to not have any slop there: the worm should

not be able to move laterally at all. When making this adjustment,

don't apply too much pressure -- finger-tight is good.



Also, make sure the two worm blocks are as parallel to each other as

possible. I've had, on occasion, adjusted them so that the left one

was slightly tilted relative to the right. Needless to say that

increased PE significantly.



Finally, take a look to make sure there's enough grease. If the worm

(or parts of the worm) look like they have no grease on them, you

may have it adjusted too tight, or may just need to regrease.



Regards,



-Paul



--- In Losmandy_users@yahoogroups.com, "John Murphy"

john_and_hong@y...> wrote: > Hi All

>

> I have recently bought a new G11 with Gemini. Although the stand

is > wonderful for visual use, I have been very dissappointed with the

> PE. The amplitude is quite reasonable, but the curve is anything

but > smooth. I have uploaded the PE to the files section (G11 PE help

> needed.xls)

>

> The telescope was carefuly balanced with a slight bias to the

east. I > have adjusted the gearbox and left worm block positions to try and

> minimise the offset between the worm shaft and the gearbox shaft.

The > right worm block has been adjusted to allow some backlash. It

> is now possible to rotate the worm without the hinges of the

Oldham > coupler moving up and down (it was over 0.5mm out both horizontaly

> and verticaly). This has improved the PE but as you can see it

still > has a large random element to it and this makes it too rough.

>

> I assume that the worm is always at a tangent to the main wheel -

> adjusting the angle of the worm would just move the contact point

> left or right along the worm.

>

> Of course the worm might not be in the plane of the wheel - anyone

> know how I could check for this?

>

> Any ideas on what the problem might be?

>

> Thanks

> John Murphy



----------------------------

#26457 Jul 21, 2005

I am in the same boat, so you are not alone. I will be doing the same

things you are. I have contacted scott and swapped the worms, and

adjusted them as well. no dice.

I will adjust the worm to be parellel to the motor shaft next ( with

feelers ) I dont care about +4 - 3 PE only the secondary waveforms tha

cause trouble at long focal lengths or with fainter guide stars.



--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@h...> wrote:

> Hi John,

>

> For best performance in a G11, the motor shaft, oldham coupler and

> the worm should be in as straight a line as possible. Furthermore,

> because the worm is decoupled from the motor, it is important to

> have the worm blocks equidistant from the gear cover. This helps

> make the worm as parallel to the motor shaft as possible.

>

> To accomplish this, use automotive feeler gauges to measure the

> distance between the worm blocks and the gear cover. These should be

> very nearly the same.

>

> Another important adjustment is the worm float between the two worm

> posts. It is important to not have any slop there: the worm should

> not be able to move laterally at all. When making this adjustment,

> don't apply too much pressure -- finger-tight is good.

>

> Also, make sure the two worm blocks are as parallel to each other as

> possible. I've had, on occasion, adjusted them so that the left one

> was slightly tilted relative to the right. Needless to say that

> increased PE significantly.

>

> Finally, take a look to make sure there's enough grease. If the worm

> (or parts of the worm) look like they have no grease on them, you

> may have it adjusted too tight, or may just need to regrease.

>

> Regards,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "John Murphy"

> john_and_hong@y...> wrote:

> > Hi All

> >

> > I have recently bought a new G11 with Gemini. Although the stand

> is

> > wonderful for visual use, I have been very dissappointed with the

> > PE. The amplitude is quite reasonable, but the curve is anything

> but

> > smooth. I have uploaded the PE to the files section (G11 PE help

> > needed.xls)

> >

> > The telescope was carefuly balanced with a slight bias to the

> east. I

> > have adjusted the gearbox and left worm block positions to try and

> > minimise the offset between the worm shaft and the gearbox shaft.

> The

> > right worm block has been adjusted to allow some backlash. It

> > is now possible to rotate the worm without the hinges of the

> Oldham

> > coupler moving up and down (it was over 0.5mm out both horizontaly

> > and verticaly). This has improved the PE but as you can see it

> still

> > has a large random element to it and this makes it too rough.

> >

> > I assume that the worm is always at a tangent to the main wheel -

> > adjusting the angle of the worm would just move the contact point

> > left or right along the worm.

> >

> > Of course the worm might not be in the plane of the wheel - anyone

> > know how I could check for this?

> >

> > Any ideas on what the problem might be?

> >

> > Thanks

> > John Murphy







----------------------------

#26458 Jul 22, 2005

Hi,

I was on the same boat some years ago... but now I'm on the earth ;-)



Ok, I know tweaking the G11 for maximum performance in ccd-field isn't

a joke, but the written procedure is right. I must say that could be

also useful trying to rotate manually the worm with no motor

installed, in order to check for optimum worm / gear performance.

Using an high quality litium grease will help during cold winter's night.

I've also swapped the AR/DEC worms, but the most important thingh is

parallelism and coupling with the gears. Don't be discouraged,

everything will work just fine... Only a bit of time and patience is

required!



Good luck.

Stefano Vezzosi

--- In Losmandy_users@yahoogroups.com, "glacy31" glacy31@y...> wrote:

> I am in the same boat, so you are not alone. I will be doing the same

> things you are. I have contacted scott and swapped the worms, and

> adjusted them as well. no dice.

> I will adjust the worm to be parellel to the motor shaft next ( with

> feelers ) I dont care about +4 - 3 PE only the secondary waveforms tha

> cause trouble at long focal lengths or with fainter guide stars.

>

>

> --- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@h...> wrote:

> > Hi John,

> >

> > For best performance in a G11, the motor shaft, oldham coupler and

> > the worm should be in as straight a line as possible. Furthermore,

> > because the worm is decoupled from the motor, it is important to

> > have the worm blocks equidistant from the gear cover. This helps

> > make the worm as parallel to the motor shaft as possible.

> >

> > To accomplish this, use automotive feeler gauges to measure the

> > distance between the worm blocks and the gear cover. These should be

> > very nearly the same.

> >

> > Another important adjustment is the worm float between the two worm

> > posts. It is important to not have any slop there: the worm should

> > not be able to move laterally at all. When making this adjustment,

> > don't apply too much pressure -- finger-tight is good.

> >

> > Also, make sure the two worm blocks are as parallel to each other as

> > possible. I've had, on occasion, adjusted them so that the left one

> > was slightly tilted relative to the right. Needless to say that

> > increased PE significantly.

> >

> > Finally, take a look to make sure there's enough grease. If the worm

> > (or parts of the worm) look like they have no grease on them, you

> > may have it adjusted too tight, or may just need to regrease.

> >

> > Regards,

> >

> > -Paul

> >

> > --- In Losmandy_users@yahoogroups.com, "John Murphy"

> > john_and_hong@y...> wrote:

> > > Hi All

> > >

> > > I have recently bought a new G11 with Gemini. Although the stand

> > is

> > > wonderful for visual use, I have been very dissappointed with the

> > > PE. The amplitude is quite reasonable, but the curve is anything

> > but

> > > smooth. I have uploaded the PE to the files section (G11 PE help

> > > needed.xls)

> > >

> > > The telescope was carefuly balanced with a slight bias to the

> > east. I

> > > have adjusted the gearbox and left worm block positions to try and

> > > minimise the offset between the worm shaft and the gearbox shaft.

> > The

> > > right worm block has been adjusted to allow some backlash. It

> > > is now possible to rotate the worm without the hinges of the

> > Oldham

> > > coupler moving up and down (it was over 0.5mm out both horizontaly

> > > and verticaly). This has improved the PE but as you can see it

> > still

> > > has a large random element to it and this makes it too rough.

> > >

> > > I assume that the worm is always at a tangent to the main wheel -

> > > adjusting the angle of the worm would just move the contact point

> > > left or right along the worm.

> > >

> > > Of course the worm might not be in the plane of the wheel - anyone

> > > know how I could check for this?

> > >

> > > Any ideas on what the problem might be?

> > >

> > > Thanks

> > > John Murphy



----------------------------

#26468 Jul 22, 2005

Hello, I'm joining the club. Was rather dissapointed with the out of

the box performance of my 2 week old G11. The machining of the parts

is a thing of beauty but the worm adjustment/gearbox alignment needs

work. I'm trying to get up the courage to open up the right hole to

allow adjustment. I will follow this thread to see how it works out.

Just put the thing back together and am thinking I should have lubed

the Oldham Coupler as with the best shaft alignment I could get it is

going to be working quite a bit.

Bill



--- In Losmandy_users@yahoogroups.com, "John Murphy"

john_and_hong@y...> wrote: > Hi All

>

> I have recently bought a new G11 with Gemini. Although the stand is

> wonderful for visual use, I have been very dissappointed with the

> PE. The amplitude is quite reasonable, but the curve is anything

but > smooth. I have uploaded the PE to the files section (G11 PE help

> needed.xls)

>

> The telescope was carefuly balanced with a slight bias to the east.

I > have adjusted the gearbox and left worm block positions to try and

> minimise the offset between the worm shaft and the gearbox shaft.

The > right worm block has been adjusted to allow some backlash. It

> is now possible to rotate the worm without the hinges of the Oldham

> coupler moving up and down (it was over 0.5mm out both horizontaly

> and verticaly). This has improved the PE but as you can see it

still > has a large random element to it and this makes it too rough.

>

> I assume that the worm is always at a tangent to the main wheel -

> adjusting the angle of the worm would just move the contact point

> left or right along the worm.

>

> Of course the worm might not be in the plane of the wheel - anyone

> know how I could check for this?

>

> Any ideas on what the problem might be?

>

> Thanks

> John Murphy







----------------------------

#26469 Jul 22, 2005

Hi Bill,



Before you open up any bore of the Base plate first check the aligment

of the worm to the gear axle. That should be the only reason to make a

bore wider than they are originally.



In any case the right bore (standing in front of the mount, motors to

the left) is already bigger then the left bore and is big enough alredy

to allow any adjustment. It even allows you to press the worm so far in

that you can not move the worm anymore ! so be careful about the right

bore.



So if you have to open up any bore it would be the left one, that is

the one which houses the block through which the worm goes through.



The danger exists that if you open up too much the left bore you will

need far more adjustment time because then you will deal with one more

variable.



Moving the left block will mean to readjust the right block and so on :-

))



regards Rainer





--- In Losmandy_users@yahoogroups.com, "billkny" billkny@y...> wrote:

> Hello, I'm joining the club. Was rather dissapointed with the out of

> the box performance of my 2 week old G11. The machining of the parts

> is a thing of beauty but the worm adjustment/gearbox alignment needs

> work. I'm trying to get up the courage to open up the right hole to

> allow adjustment. I will follow this thread to see how it works out.

> Just put the thing back together and am thinking I should have lubed

> the Oldham Coupler as with the best shaft alignment I could get it is

> going to be working quite a bit.

> Bill



----------------------------

#26470 Jul 23, 2005

Thanks for the reply, I was identifying the holes as standing at

the back of the mount, the hole I was refering to was the one nearest

the motor. When I adjust the RIGHT block (away from motor) so the

worm turns freely but has minimal endplay and as close to the driven

gear as possible without binding the Oldham coupler is visibly out of

line. I have been thinking about removing some material from the lug

on the worm block where it fits into the hole in the mount as that

would seem less permanent than enlarging the hole (I assume you can

buy a replacement worm block if necessary). The PEC does a pretty

good job of taking the error out of the system as it is but it would

seem much better to taks as much error out of the system as possible

and leave the PEC to compensate only for error in the worm it's self

Bill

--- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...> wrote:

> Hi Bill,

>

> Before you open up any bore of the Base plate first check the

aligment

> of the worm to the gear axle. That should be the only reason to

make a

> bore wider than they are originally.

>

> In any case the right bore (standing in front of the mount, motors

to

> the left) is already bigger then the left bore and is big enough

alredy

> to allow any adjustment. It even allows you to press the worm so

far in

> that you can not move the worm anymore ! so be careful about the

right

> bore.

>

> So if you have to open up any bore it would be the left one, that

is

> the one which houses the block through which the worm goes through.

>

> The danger exists that if you open up too much the left bore you

will

> need far more adjustment time because then you will deal with one

more

> variable.

>

> Moving the left block will mean to readjust the right block and so

on :-

> ))

>

> regards Rainer

>

>

>

> --- In Losmandy_users@yahoogroups.com, "billkny" billkny@y...>

wrote:

> > Hello, I'm joining the club. Was rather dissapointed with the

out of

> > the box performance of my 2 week old G11. The machining of the

parts

> > is a thing of beauty but the worm adjustment/gearbox alignment

needs

> > work. I'm trying to get up the courage to open up the right hole

to

> > allow adjustment. I will follow this thread to see how it works

out.

> > Just put the thing back together and am thinking I should have

lubed

> > the Oldham Coupler as with the best shaft alignment I could get

it is

> > going to be working quite a bit.

> > Bill



----------------------------

#26471 Jul 23, 2005

HI



i actually did quite a bit of study on this problem of pe...i was

trying to improve the pe on my Ci700 mount...which i managed to get

quite and improvement...what i found is that most of the pe are not

in the worm at all...think about it..the worm is under pressure that

forces against the bearing that is pretty much locked...the contact

of the worm to the gearing is pretty much in a fixed positon all the

time...whereas the spur gears are not like this...most of this

erratic error is in the spur gears. i tested this by running

different arrangements of spur gears and belts and pulleys.....i just

got my g11.and tested the pe...at first i was getting results pretty

much like you experienced...i took off the motor and readjusted it

mounting....basically about 1/10 a degree on the spur gears can cause

an arc second of error...so...getting the spur gear in the precise

position is important...after the adjustments my error was reduced to

about plus or minus 3 arc seconds...a big improvement...also..it was

very smooth...



another big factor is how the pe is measured..i have to set up each

night by drift aligning using a camera...so i get to see the pe each

night i setup the scope...seeing conditions have a huge factor on the

pe....in poor seeing conditions...the pe star can move up

to...gulp..max i've seen is 12 arc seconds.(100+ degree heat day).and

stay there for about 3 to 4 seconds...so..on a normal seeing day of 3

to 4 arc seconds...you can expect some large jumps...it's best to run

this pe test near 2 or 3 am when conditions have calmed down the

most...



jamie



--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@h...>

wrote: > Hi John,

>

> For best performance in a G11, the motor shaft, oldham coupler and

> the worm should be in as straight a line as possible. Furthermore,

> because the worm is decoupled from the motor, it is important to

> have the worm blocks equidistant from the gear cover. This helps

> make the worm as parallel to the motor shaft as possible.

>

> To accomplish this, use automotive feeler gauges to measure the

> distance between the worm blocks and the gear cover. These should

be > very nearly the same.

>

> Another important adjustment is the worm float between the two worm

> posts. It is important to not have any slop there: the worm should

> not be able to move laterally at all. When making this adjustment,

> don't apply too much pressure -- finger-tight is good.

>

> Also, make sure the two worm blocks are as parallel to each other

as > possible. I've had, on occasion, adjusted them so that the left one

> was slightly tilted relative to the right. Needless to say that

> increased PE significantly.

>

> Finally, take a look to make sure there's enough grease. If the

worm > (or parts of the worm) look like they have no grease on them, you

> may have it adjusted too tight, or may just need to regrease.

>

> Regards,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "John Murphy"

> john_and_hong@y...> wrote:

> > Hi All

> >

> > I have recently bought a new G11 with Gemini. Although the stand

> is

> > wonderful for visual use, I have been very dissappointed with the

> > PE. The amplitude is quite reasonable, but the curve is anything

> but

> > smooth. I have uploaded the PE to the files section (G11 PE help

> > needed.xls)

> >

> > The telescope was carefuly balanced with a slight bias to the

> east. I

> > have adjusted the gearbox and left worm block positions to try

and > > minimise the offset between the worm shaft and the gearbox shaft.

> The

> > right worm block has been adjusted to allow some backlash. It

> > is now possible to rotate the worm without the hinges of the

> Oldham

> > coupler moving up and down (it was over 0.5mm out both

horizontaly > > and verticaly). This has improved the PE but as you can see it

> still

> > has a large random element to it and this makes it too rough.

> >

> > I assume that the worm is always at a tangent to the main wheel -

> > adjusting the angle of the worm would just move the contact point

> > left or right along the worm.

> >

> > Of course the worm might not be in the plane of the wheel -

anyone > > know how I could check for this?

> >

> > Any ideas on what the problem might be?

> >

> > Thanks

> > John Murphy







----------------------------

#27618 Oct 29, 2005

Hi,



What is the average periodic error of the G11 ?

Thanks,

Andre



----------------------------

#27621 Oct 29, 2005

Hi,



I would say they are in a range of +-3" to +-7" arcseconds, so averages

out to +-5"



regards Rainer







--- In Losmandy_users@yahoogroups.com, Andr. Moutinho moutinho@b...>

wrote: >

> Hi,

>

> What is the average periodic error of the G11 ?

> Thanks,

> Andre

>



----------------------------

#28892 Feb 20 8:32 PM

HI Guys,



Just new to the group.



I am fairly new to astronomy and Astrophotography but I have built

myself an observatory here In Brisbane Australia, which houses my

C11 and ED 80 ontop of the losmandy G11 with gemini.



The problem I am having is my pec is horrible and no matter how much

I train it does nothing....my polar align is good and I just

recently adjusted the worm to get rid of the bad backlash I had on

the Dec axis...never had any on the RA axis.



So at the moment I have no backlash..NO motor stalls or over heating

problems..very good accuarcy but terrible pec...that bad that a 20

second exposure is useless.



If you can send me to some links or give us some advice is much

appreciated...



BTW the G11 is new...only around 6 months old puchased new with

gemini.



You can check out the set up here and some images.



www.users.on.net/~striker/



Tony



----------------------------

#28894 Feb 20 11:39 PM

Tony,







How much does your instrument package weigh? I use a TOA-130, small guide

scope, and STV and I think I am probably at my limit. The TOA alone weighs

10Kg. I once tried the TOA + TV-85 on a saddle plate plus STV and Canon

20Da at the same time. I estimate it all weighed about 37 pounds plus or

minus and need about 35 pounds of counter weights to come to balance. I

notice the scope would easily oscillate if bumped or the wind blew. The

tracking was horrible. I could probably tweak the balance and turn down the

tracking aggressiveness and get by but I think that is the mount's upper

limit.







I noticed you are using about 40 pounds of counter weight to balance your

rig. If you are then you are probably carrying more weight than I was. If

so, consider a smaller (light weight) guide scope and try again.



Good luck.







Kyle







_____



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

On Behalf Of strikernew

Sent: Monday, February 20, 2006 8:32 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] G11 Pec issue







HI Guys,



Just new to the group.



I am fairly new to astronomy and Astrophotography but I have built

myself an observatory here In Brisbane Australia, which houses my

C11 and ED 80 ontop of the losmandy G11 with gemini.



The problem I am having is my pec is horrible and no matter how much

I train it does nothing....my polar align is good and I just

recently adjusted the worm to get rid of the bad backlash I had on

the Dec axis...never had any on the RA axis.



So at the moment I have no backlash..NO motor stalls or over heating

problems..very good accuarcy but terrible pec...that bad that a 20

second exposure is useless.



If you can send me to some links or give us some advice is much

appreciated...



BTW the G11 is new...only around 6 months old puchased new with

gemini.



You can check out the set up here and some images.



www.users.on.net/~striker/



Tony













SPONSORED LINKS





Astronomy

groups.yahoo.com/gads?t=ms&k=Astronomy+magazine&w1=Astronomy+magazin

e&w2=Astronomy+telescope&w3=Tube+assembly&c=3&s=68&.sig=AMOQDCoQ_-vb38KIwH_-

yQ> magazine



Astronomy

groups.yahoo.com/gads?t=ms&k=Astronomy+telescope&w1=Astronomy+magazi

ne&w2=Astronomy+telescope&w3=Tube+assembly&c=3&s=68&.sig=Z73_2h7Cf70g1rCESP9

Fuw> telescope



Tube

groups.yahoo.com/gads?t=ms&k=Tube+assembly&w1=Astronomy+magazine&w2=

Astronomy+telescope&w3=Tube+assembly&c=3&s=68&.sig=p4GTdx3ixuYCYIgJnChXiA>

assembly







_____



YAHOO! GROUPS LINKS







*. Visit your group "Losmandy_users

groups.yahoo.com/group/Losmandy_users> " on the web.



*. To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@yahoogroups.com

mailto:Losmandy_users-unsubscribe@yahoogroups.com?subject=Unsubscribe>



*. Your use of Yahoo! Groups is subject to the Yahoo!

docs.yahoo.com/info/terms/> Terms of Service.







_____







[Non-text portions of this message have been removed]







----------------------------

#28895 Feb 21 2:28 AM

Hi Tony,



Gooday from NSW!



There are possibly two sources of your terrible PEC. The first is an

over-adjustment for backlash which may result in binding of the RA gear. It is

not really necessary to eliminate backlash in the RA gear as the motor generally

goes in one direction. A little backlash is good in so far as it helps to

prevent binding of the gears. Binding of the gears will result in an irregular

jerky motion, rather than the smooth and regular curve of periodic error.



The second most probable cause of bad PEC is a fault in Level 3 firmware that

appears to add RA drift to PEC. This has been corrected in Level 4, which is

almost due for release, and will be available at the small cost of upgrading

your EPROM chip.



You don't say whether you are using a CCD for astrophotography, but if so, you

can use its software to measure periodic error and plot it as a curve. This will

help members of the group diagnose your problem, as once they can see the nature

of your periodic error they can usually suggest the cause.



- Greg







-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com] On

Behalf Of strikernew

Sent: Tuesday, 21 February 2006 3:32 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] G11 Pec issue



HI Guys,



Just new to the group.



I am fairly new to astronomy and Astrophotography but I have built

myself an observatory here In Brisbane Australia, which houses my

C11 and ED 80 ontop of the losmandy G11 with gemini.



The problem I am having is my pec is horrible and no matter how much

I train it does nothing....my polar align is good and I just

recently adjusted the worm to get rid of the bad backlash I had on

the Dec axis...never had any on the RA axis.



So at the moment I have no backlash..NO motor stalls or over heating

problems..very good accuarcy but terrible pec...that bad that a 20

second exposure is useless.



If you can send me to some links or give us some advice is much

appreciated...



BTW the G11 is new...only around 6 months old puchased new with

gemini.



You can check out the set up here and some images.



www.users.on.net/~striker/



Tony













Yahoo! Groups Links



----------------------------

#28896 Feb 21 2:32 AM

Thanks Kyle,



I have ordered a Lumicon Off axis guider to try guiding throught

the SCT...I may take of the guide scope all together and see how

that goes.









--- In Losmandy_users@yahoogroups.com, "Kyle Coker" kcoker@...>

wrote: >

> Tony,

>

>

>

> How much does your instrument package weigh? I use a TOA-130,

small guide > scope, and STV and I think I am probably at my limit. The TOA

alone weighs > 10Kg. I once tried the TOA + TV-85 on a saddle plate plus STV and

Canon > 20Da at the same time. I estimate it all weighed about 37 pounds

plus or > minus and need about 35 pounds of counter weights to come to

balance. I > notice the scope would easily oscillate if bumped or the wind

blew. The > tracking was horrible. I could probably tweak the balance and

turn down the > tracking aggressiveness and get by but I think that is the mount's

upper > limit.

>

>

>

> I noticed you are using about 40 pounds of counter weight to

balance your > rig. If you are then you are probably carrying more weight than I

was. If > so, consider a smaller (light weight) guide scope and try again.

>

> Good luck.

>

>

>

> Kyle

>

>

>

> _____

>

> From: Losmandy_users@yahoogroups.com

[mailto:Losmandy_users@yahoogroups.com] > On Behalf Of strikernew

> Sent: Monday, February 20, 2006 8:32 PM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] G11 Pec issue

>

>

>

> HI Guys,

>

> Just new to the group.

>

> I am fairly new to astronomy and Astrophotography but I have built

> myself an observatory here In Brisbane Australia, which houses my

> C11 and ED 80 ontop of the losmandy G11 with gemini.

>

> The problem I am having is my pec is horrible and no matter how

much > I train it does nothing....my polar align is good and I just

> recently adjusted the worm to get rid of the bad backlash I had on

> the Dec axis...never had any on the RA axis.

>

> So at the moment I have no backlash..NO motor stalls or over

heating > problems..very good accuarcy but terrible pec...that bad that a 20

> second exposure is useless.

>

> If you can send me to some links or give us some advice is much

> appreciated...

>

> BTW the G11 is new...only around 6 months old puchased new with

> gemini.

>

> You can check out the set up here and some images.

>

> www.users.on.net/~striker/

>

> Tony

>

>

>

>

>

>

> SPONSORED LINKS

>

>

> Astronomy

> groups.yahoo.com/gads?

t=ms&k=Astronomy+magazine&w1=Astronomy+magazin > e&w2=Astronomy+telescope&w3=Tube+assembly&c=3&s=68&.sig=AMOQDCoQ_-

vb38KIwH_- > yQ> magazine

>

> Astronomy

> groups.yahoo.com/gads?

t=ms&k=Astronomy+telescope&w1=Astronomy+magazi >

ne&w2=Astronomy+telescope&w3=Tube+assembly&c=3&s=68&.sig=Z73_2h7Cf70g

1rCESP9 > Fuw> telescope

>

> Tube

> groups.yahoo.com/gads?

t=ms&k=Tube+assembly&w1=Astronomy+magazine&w2= >

Astronomy+telescope&w3=Tube+assembly&c=3&s=68&.sig=p4GTdx3ixuYCYIgJnC

hXiA> > assembly

>

>

>

> _____

>

> YAHOO! GROUPS LINKS

>

>

>

> *. Visit your group "Losmandy_users

> groups.yahoo.com/group/Losmandy_users> " on the web.

>

> *. To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@yahoogroups.com

> mailto:Losmandy_users-unsubscribe@yahoogroups.com?

subject=Unsubscribe> >

> *. Your use of Yahoo! Groups is subject to the Yahoo!

> docs.yahoo.com/info/terms/> Terms of Service.

>

>

>

> _____

>

>

>

> [Non-text portions of this message have been removed]

>







----------------------------

#28897 Feb 21 4:49 AM

strikernew wrote:

>

>I am fairly new to astronomy and Astrophotography but I have built

>myself an observatory here In Brisbane Australia, which houses my

>C11 and ED 80 ontop of the losmandy G11 with gemini.

>

>



Hi Tony,



Congrats on the nice set-up.

>The problem I am having is my pec is horrible and no matter how much

>I train it does nothing....my polar align is good and I just

>recently adjusted the worm to get rid of the bad backlash I had on

>the Dec axis...never had any on the RA axis.

>

>



Does your G-11 have the new worm in RA ? (If it was new it probably does)



I would not attempt to measure the PE with the SCT because of issues

associated with that design.

If you image through the refractor what do you find ?

>So at the moment I have no backlash..

>



Then you have the worms adjusted too tight. Backlash is inevitable. The

best you can do is to minimise it.

>NO motor stalls or over heating

>problems..very good accuarcy but terrible pec...that bad that a 20

>second exposure is useless.

>

>

You are talking about unguided exposures ? Are you aware that there is a

problem with PEC and the L3 ROM ? Turn off PEC and recheck.

>If you can send me to some links or give us some advice is much

>appreciated...

>

>BTW the G11 is new...only around 6 months old puchased new with

>gemini.

>

>

I have an almost identical setup, perhaps a bit more weight because of

the bigger refractor (guidescope) and can easily image 30 seconds

unguided and 60 seconds most of the time. But .... the G-11 is not

advertised as being capable of doing unguided exposures. It is

advertised as being guided. So you need to look at your tracking errors

and then determine if they are such that they can be guided out ? This

is a subtle nuance that's easy to miss.



PE is the periodic error of the mount. PEC is the built in Correction

capability of the Gemini to control that PE which exists in RA.



Also make sure that the mount is heavier to the East. ie: OTA's on the

West of the mount there should be a slight tendancy for the mount to

move to the East with the clutches loosened. Perfect balance can present

problems. You always want the RA gear engaged on the same side of the

tooth and moving "uphill" when running.



Regards



Bill

>

>

>





--



William R. Mattil.:.www.celestial-images.com



----------------------------

#28899 Feb 21 5:45 AM

You can check out the set up here and some images.

>www.users.on.net/~striker/



Tony,



Very interesting pier! Can you tell us more about it?



- Greg



----------------------------

#28906 Feb 21 6:23 PM

Yeah no problem Greg,



It's something that we put a lot of work into as it is the basis of

a solid foundation for the G11....



Fistly the pier sits on a seperate concrete slab to the shed itself

with a slab size 1 cubic meter it does bell out a little on the

bottom as well.



The pier is made out of Stainless steel.....I was lucky to have my

father in law who is a boilermaker with stainless build it for me

for free....this job in itself would cost over $2000 AUD to make.



The approximate weight of the pier empty was 80KG's but I have also

filled it up with river sand so I would hate to move it now....it's

also bolted down to the concrete via 4 stainless steel bolts also

lodged into the concrete.



I have uploaded some more pics of the top 2 adjustable plates when I

first sat my EQ6 mount on top.



www.users.on.net/~striker/



They too are solid stainless steel plates....very very heavy.



The preference to do it in stainless steel was not my decision but

when he said he could it in stainless I said go for it...lol



You have to love Mates rates...hahaha









--- In Losmandy_users@yahoogroups.com, "Greg Crawford" gc@...>

wrote: >

> >You can check out the set up here and some images.

> >www.users.on.net/~striker/

>

> Tony,

>

> Very interesting pier! Can you tell us more about it?

>

> - Greg

>



----------------------------

#28907 Feb 21 6:33 PM

--- In Losmandy_users@yahoogroups.com, "William R. Mattil"

wrmattil@...> wrote: >

> strikernew wrote:

>

> >

> >I am fairly new to astronomy and Astrophotography but I have

built > >myself an observatory here In Brisbane Australia, which houses my

> >C11 and ED 80 ontop of the losmandy G11 with gemini.

> >

> >

>

> Hi Tony,

>

> Congrats on the nice set-up.

>

> >The problem I am having is my pec is horrible and no matter how

much > >I train it does nothing....my polar align is good and I just

> >recently adjusted the worm to get rid of the bad backlash I had

on > >the Dec axis...never had any on the RA axis.

> >

> >

>

> Does your G-11 have the new worm in RA ? (If it was new it

probably does) >

> I would not attempt to measure the PE with the SCT because of

issues > associated with that design.

> If you image through the refractor what do you find ?

>

> >So at the moment I have no backlash..

> >

>

> Then you have the worms adjusted too tight. Backlash is

inevitable. The > best you can do is to minimise it.

>

> >NO motor stalls or over heating

> >problems..very good accuarcy but terrible pec...that bad that a

20 > >second exposure is useless.

> >

> >

> You are talking about unguided exposures ? Are you aware that

there is a > problem with PEC and the L3 ROM ? Turn off PEC and recheck.

>

> >If you can send me to some links or give us some advice is much

> >appreciated...

> >

> >BTW the G11 is new...only around 6 months old puchased new with

> >gemini.

> >

> >

> I have an almost identical setup, perhaps a bit more weight

because of > the bigger refractor (guidescope) and can easily image 30 seconds

> unguided and 60 seconds most of the time. But .... the G-11 is not

> advertised as being capable of doing unguided exposures. It is

> advertised as being guided. So you need to look at your tracking

errors > and then determine if they are such that they can be guided out ?

This > is a subtle nuance that's easy to miss.

>

> PE is the periodic error of the mount. PEC is the built in

Correction > capability of the Gemini to control that PE which exists in RA.

>

> Also make sure that the mount is heavier to the East. ie: OTA's on

the > West of the mount there should be a slight tendancy for the mount

to > move to the East with the clutches loosened. Perfect balance can

present > problems. You always want the RA gear engaged on the same side of

the > tooth and moving "uphill" when running.

>

> Regards

>

> Bill

>

> >

> >

> >

>

>

> --

>

> William R. Mattil.:.www.celestial-images.com



Thanks guys and Bill,



I have few more things to try tonight....I was going to give it a go

without the guidescope to reduce weight but I will try a few other

options first.....



When I take a 30 second exposure it comes out looking like 2 star

with star trail between them...like when we were young and were

playing join the dots....hehehe



The problem is recent....I have managed to take a 7 minute unguided

image of the tarantula with no star trail at FL2800mm....but at the

moment I cant image anything....I must have got lucky with that

image and it is close to polar south.



I will keep trying but very frustrated at the moment. >







----------------------------

#31493 Nov 19, 2006

Hello,



Yesterday, I tried to make a PE curve with my G11 using a ED80 at

400mm focal lenght and the tracking ccd of my ST7e ccd camera and the

software CCDsoftv5.



You can find the files here:



tech.groups.yahoo.com/group/Losmandy_users/files/Sjoerd%20Dufoer/



You may also have a look at the corrections that were needed by the

autoguider.



It seems that my new G11 have a large periodic error of almost 20

arcsec. The curve also don't looks that smooth. It can be that there

are errors because I used a very small focal lenght for generating

this curve. 1 pixel on the tracking CCD (tp211) was 7 arcsec. The

curve looks pretty periodic but not ver smooth !



My question is: Can I use this mount for autoguiding with larger focal

lenghts? I want to use focal lenghts of 1600mm and even higher !



Regards,

Sjoerd Dufoer



----------------------------

#31496 Nov 19, 2006

Yes it's very possible but it will take a few upgrades and adjustments. Read the archives for details.



Here are a few autoguided images at just over 1600mm Using my G-11 mount and a C-11 scope. The galaxy is a series of 20 minute exposures and the nebula are a series of 45 minute exposures.....



The first is the spiral galaxy, NGC-6946.

publicmissiles.com/franku/10-16-06_NGC_6946-Processed.jpg



Next is the famous Pac Man Nebula, IC-1590.

publicmissiles.com/franku/IC_1590_SigmaProcessed.jpg



And last but not least, The Pelican Nebula.

publicmissiles.com/franku/Pelican_InProcess.jpg





---Frank Rocketman Uroda



----- Original Message -----

From: sdufoer

To: Losmandy_users@yahoogroups.com

Sent: Sunday, November 19, 2006 10:48 AM

Subject: [Losmandy_users] G11 Periodic error





Hello,



Yesterday, I tried to make a PE curve with my G11 using a ED80 at

400mm focal lenght and the tracking ccd of my ST7e ccd camera and the

software CCDsoftv5.



You can find the files here:



tech.groups.yahoo.com/group/Losmandy_users/files/Sjoerd%20Dufoer/



You may also have a look at the corrections that were needed by the

autoguider.



It seems that my new G11 have a large periodic error of almost 20

arcsec. The curve also don't looks that smooth. It can be that there

are errors because I used a very small focal lenght for generating

this curve. 1 pixel on the tracking CCD (tp211) was 7 arcsec. The

curve looks pretty periodic but not ver smooth !



My question is: Can I use this mount for autoguiding with larger focal

lenghts? I want to use focal lenghts of 1600mm and even higher !



Regards,

Sjoerd Dufoer











[Non-text portions of this message have been removed]



----------------------------

#31497 Nov 19, 2006

Oh yeah. Now I see the Pelican. It's "sideways." This is a rather

tough object to get (full scale) in a C11...



regards

Greg N



--- In Losmandy_users@yahoogroups.com, "Photon Collector"

photoncollector@...> wrote: >

> Yes it's very possible but it will take a few upgrades and

adjustments. Read the archives for details. >

> Here are a few autoguided images at just over 1600mm Using my G-11

mount and a C-11 scope. The galaxy is a series of 20 minute exposures

and the nebula are a series of 45 minute exposures..... >



----------------------------

#31499 Nov 19, 2006

No, it's the Pelican... Actually, it a small part of it at this FOV.



---Frank Rocketman Uroda



----- Original Message -----

From: gnowellsct

To: Losmandy_users@yahoogroups.com

Sent: Sunday, November 19, 2006 9:12 PM

Subject: [Losmandy_users] Re: G11 Periodic error





That's REAL nice work Frank. Your Pelican Nebula to me looks like the

Elephant's trunk (IC 1396). Possibly I am confused. Indeed quite

possibly.



regards Greg N



--- In Losmandy_users@yahoogroups.com, "Photon Collector"

photoncollector@...> wrote:

>

> Yes it's very possible but it will take a few upgrades and

adjustments. Read the archives for details.

>

> Here are a few autoguided images at just over 1600mm Using my G-11

mount and a C-11 scope. The galaxy is a series of 20 minute exposures

and the nebula are a series of 45 minute exposures.....

>

> The first is the spiral galaxy, NGC-6946.

> publicmissiles.com/franku/10-16-06_NGC_6946-Processed.jpg

>

> Next is the famous Pac Man Nebula, IC-1590.

> publicmissiles.com/franku/IC_1590_SigmaProcessed.jpg

>

> And last but not least, The Pelican Nebula.

> publicmissiles.com/franku/Pelican_InProcess.jpg

>

>

> ---Frank Rocketman Uroda

>

>











[Non-text portions of this message have been removed]



----------------------------

#31500 Nov 19, 2006

Thanks!

Tuning the mount was a huge step forward. The second most important thing was to get collimation as good as I can. Third was to track down and eliminate a serious noise problem I was having. Forth was to focus often (every frame or two).

Now all I need is clear skies!



---Frank Rocketman Uroda



----- Original Message -----

From: gnowellsct

To: Losmandy_users@yahoogroups.com

Sent: Sunday, November 19, 2006 9:12 PM

Subject: [Losmandy_users] Re: G11 Periodic error





That's REAL nice work Frank. Your Pelican Nebula to me looks like the

Elephant's trunk (IC 1396). Possibly I am confused. Indeed quite

possibly.



regards Greg N



--- In Losmandy_users@yahoogroups.com, "Photon Collector"

photoncollector@...> wrote:

>

> Yes it's very possible but it will take a few upgrades and

adjustments. Read the archives for details.

>

> Here are a few autoguided images at just over 1600mm Using my G-11

mount and a C-11 scope. The galaxy is a series of 20 minute exposures

and the nebula are a series of 45 minute exposures.....

>

> The first is the spiral galaxy, NGC-6946.

> publicmissiles.com/franku/10-16-06_NGC_6946-Processed.jpg

>

> Next is the famous Pac Man Nebula, IC-1590.

> publicmissiles.com/franku/IC_1590_SigmaProcessed.jpg

>

> And last but not least, The Pelican Nebula.

> publicmissiles.com/franku/Pelican_InProcess.jpg

>

>

> ---Frank Rocketman Uroda

>

>











[Non-text portions of this message have been removed]







----------------------------

#31501 Nov 19, 2006

No, it's the Pelican... Actually, it a small part of it at this FOV.



Nice shot, Frank.



I imaged the same thing last year, and colored it in Photoshop to look

like a violent volcano. :) Take a look on my Nebulae page, or directly

here:

home.earthlink.net/~astro_dodd/astro-photo-nebulae-05.html>



Mike



--



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com



----------------------------

#31505 Nov 20, 2006

Hello frank,



Can you tell me in short what I need to do? Is there any danger that

I screw up the mount? I already tried a regrease of my EQ6, and that

failed (mount broken).



Regards,

Sjoerd Dufoer



--- In Losmandy_users@yahoogroups.com, "Photon Collector"

photoncollector@...> wrote: >

> Yes it's very possible but it will take a few upgrades and

adjustments. Read the archives for details. >

> Here are a few autoguided images at just over 1600mm Using my G-11

mount and a C-11 scope. The galaxy is a series of 20 minute exposures

and the nebula are a series of 45 minute exposures..... >

> The first is the spiral galaxy, NGC-6946.

> publicmissiles.com/franku/10-16-06_NGC_6946-Processed.jpg

>

> Next is the famous Pac Man Nebula, IC-1590.

> publicmissiles.com/franku/IC_1590_SigmaProcessed.jpg

>

> And last but not least, The Pelican Nebula.

> publicmissiles.com/franku/Pelican_InProcess.jpg

>

>

> ---Frank Rocketman Uroda

>

>

> ----- Original Message -----

> From: sdufoer

> To: Losmandy_users@yahoogroups.com

> Sent: Sunday, November 19, 2006 10:48 AM

> Subject: [Losmandy_users] G11 Periodic error

>

>

> Hello,

>

> Yesterday, I tried to make a PE curve with my G11 using a ED80 at

> 400mm focal lenght and the tracking ccd of my ST7e ccd camera and the

> software CCDsoftv5.

>

> You can find the files here:

>

>

tech.groups.yahoo.com/group/Losmandy_users/files/Sjoerd%20Dufoer/ >

> You may also have a look at the corrections that were needed by the

> autoguider.

>

> It seems that my new G11 have a large periodic error of almost 20

> arcsec. The curve also don't looks that smooth. It can be that there

> are errors because I used a very small focal lenght for generating

> this curve. 1 pixel on the tracking CCD (tp211) was 7 arcsec. The

> curve looks pretty periodic but not ver smooth !

>

> My question is: Can I use this mount for autoguiding with larger focal

> lenghts? I want to use focal lenghts of 1600mm and even higher !

>

> Regards,

> Sjoerd Dufoer

>

>

>

>

>

> [Non-text portions of this message have been removed]

>



----------------------------

#31615 Dec 1, 2006

Hello,



For the G11 PE problem I posted a week ago. I have run a pempro

analysis on my G11. The PE of CCDsoft and the PE that pempro has

generated are very different. Do someone knows why?



You can find the pempro results of my losmandy G11 here:

ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/7501039891



regards,

Sjoerd Dufoer



----------------------------

#31616 Dec 1, 2006

Hi Sjoerd,



I think most of the difference is that the CCDSoft graph is compressed in the

time axis compared to the PEMPro graph, thus making the peaks look sharper in

the CCDSoft graph.



-Ray

> -----Original Message-----

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com] On Behalf Of sdufoer

> Sent: Friday, December 01, 2006 7:47 AM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] G11 periodic error problem

>

> Hello,

>

> For the G11 PE problem I posted a week ago. I have run a pempro

> analysis on my G11. The PE of CCDsoft and the PE that pempro has

> generated are very different. Do someone knows why?

>

> You can find the pempro results of my losmandy G11 here:

> ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/75010

> 39891

> ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/7501039891>

>

> regards,

> Sjoerd Dufoer

>

>

>

>

>



----------------------------

#31619 Dec 2, 2006

Hello ray,



For now, my goal is to find out how it comes that the error histogram

in RA is so wide. On DEC I have a small error histogram curve, but

also with a lot of peaks in it. I started suspecting that they put no

high precision gears in it. I contacted scott to ask him if my G11 is

one with high precision gears.



Nevertheless, I want to purchase a pempro licence to program the g11

now it seems that this is possible, but I want to find the source of

the problem first. The further I can tweak this how better.



regards,

Sjoerd

--- In Losmandy_users@yahoogroups.com, "Ray Gralak" rgr@...> wrote:

>

> Hi Sjoerd,

>

> I think most of the difference is that the CCDSoft graph is

compressed in the

> time axis compared to the PEMPro graph, thus making the peaks look

sharper in

> the CCDSoft graph.

>

> -Ray

>

> > -----Original Message-----

> > From: Losmandy_users@yahoogroups.com

> > [mailto:Losmandy_users@yahoogroups.com] On Behalf Of sdufoer

> > Sent: Friday, December 01, 2006 7:47 AM

> > To: Losmandy_users@yahoogroups.com

> > Subject: [Losmandy_users] G11 periodic error problem

> >

> > Hello,

> >

> > For the G11 PE problem I posted a week ago. I have run a pempro

> > analysis on my G11. The PE of CCDsoft and the PE that pempro has

> > generated are very different. Do someone knows why?

> >

> > You can find the pempro results of my losmandy G11 here:

> > ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/75010

> > 39891

> > ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/7501039891>

> >

> > regards,

> > Sjoerd Dufoer

> >

> >

> >

> >

> >

>







----------------------------

#31626 Dec 2, 2006

Hi Sjoerd,



I believe the pempro can only program g11 gemini version.



Greetings from Brazil,



Andre Moutinho

> Hello ray,

>

> For now, my goal is to find out how it comes that the error histogram

> in RA is so wide. On DEC I have a small error histogram curve, but

> also with a lot of peaks in it. I started suspecting that they put no

> high precision gears in it. I contacted scott to ask him if my G11 is

> one with high precision gears.

>

> Nevertheless, I want to purchase a pempro licence to program the g11

> now it seems that this is possible, but I want to find the source of

> the problem first. The further I can tweak this how better.

>

> regards,

> Sjoerd

>

> --- In Losmandy_users@yahoogroups.com, "Ray Gralak" wrote:

> >

> > Hi Sjoerd,

> >

> > I think most of the difference is that the CCDSoft graph is

> compressed in the

> > time axis compared to the PEMPro graph, thus making the peaks look

> sharper in

> > the CCDSoft graph.

> >

> > -Ray

> >

> > > -----Original Message-----

> > > From: Losmandy_users@yahoogroups.com

> > > [mailto:Losmandy_users@yahoogroups.com] On Behalf Of sdufoer

> > > Sent: Friday, December 01, 2006 7:47 AM

> > > To: Losmandy_users@yahoogroups.com

> > > Subject: [Losmandy_users] G11 periodic error problem

> > >

> > > Hello,

> > >

> > > For the G11 PE problem I posted a week ago. I have run a pempro

> > > analysis on my G11. The PE of CCDsoft and the PE that pempro has

> > > generated are very different. Do someone knows why?

> > >

> > > You can find the pempro results of my losmandy G11 here:

> > > ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/75010

> > > 39891

> > >

> > >

> > > regards,

> > > Sjoerd Dufoer

> > >

> > >

> > >

> > >

> > >

> >

>

>

>

Visite minha astropage:

moutinho.astrodatabase.net





[Non-text portions of this message have been removed]



----------------------------

#31635 Dec 1, 2006

Look at your last graph. There is a peak around 3.1. This is the

"76 seconds error" (240 seconds divided by 3.1 is approximately

equal to 76 seconds). My mount also suffers from this problem

and, since I had the ST-7, I bought an AO-7 unit. It is an

expensive cure, but it has really helped solving the problem.



My OTA is an 8-inch Newton f/5. Most of the times I can find

a guiding star bright enough to guide with 1 sec exposures

(without rotating the camera), and very often I can take shorter

exposures for the guiding chip. Then the guiding is quite good.



I would really like to have my mount fixed, but I am afraid that

if I start trying to tune it, I will spend endless hours in

the job, and I am afraid it might end up in a worse condition

that it is now!



Anyway, the AO-7 is not the perfect cure: since the guiding

chip is behind the filter, using a narrow band filter will

force you to use long integration times for the guiding.





--- In Losmandy_users@yahoogroups.com, "sdufoer" sdufoer@...> wrote:

>

> Hello,

>

> For the G11 PE problem I posted a week ago. I have run a pempro

> analysis on my G11. The PE of CCDsoft and the PE that pempro has

> generated are very different. Do someone knows why?

>

> You can find the pempro results of my losmandy G11 here:

> ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/7501039891

>

> regards,

> Sjoerd Dufoer

>



----------------------------

#31637 Dec 3, 2006

Hello,



Tomas, you image at f=1000mm. This is fairly low. It's a bit

outrageous that you have to buy a AO-7 unit to let your G11 work. If

I buy extra pieces here and there, I could almost have invested in a

ap600... It's also a lot of extra weight. My opinion is that a mount

has to work if you buy it. I am very interested in your PE graph.

Can you send it to me?



Andre, Ray Gralak from CDDware told me that I can program the G11

mount with the PEC function of the standard G11. I was also

supprised, but I think I have to try it.



And here is some other news: yesterday, I opened the worm box and I

saw that the worm was not exactly perpendicular on the gear. I

loosened the worm and fastened it again with a bit less pressure on

the right side as you can see on this picture:

www.astronomie.be/sdufoer/g11/3.jpg



And wonder o wonder, after a day with a lot of rain, it cleared out.

I set everything up (in a hurry), and made a new pe-graph with the

"modification". This is the PE that I received (ed80, G11 and ccdsoft):

www.astronomie.be/sdufoer/g11/PE_modified_02122006.jpg

The errors on the DEC axis you can find here:

www.astronomie.be/sdufoer/g11/DEC_modified_02122006.jpg



What I see here is that my PE of +-10 arcsec has gone down to +- 5

arcsec, BUT I have more of the rapid and steep peaks. He makes jumps

of 10 arcsec in a few seconds... :-s



Then I tried to do autoguiding, and these are some graphs that I made:

www.astronomie.be/sdufoer/g11/error1.jpg

www.astronomie.be/sdufoer/g11/error2.jpg

www.astronomie.be/sdufoer/g11/error3.jpg

And after that it became cloudy.



So, has anyone a clue about what's going on here? There is a

component that I have to replace, but what one is it?

-The worm?

-The engine?

-The drive system?

-The gear?



Regards,

Sjoerd Dufoer





--- In Losmandy_users@yahoogroups.com, "tlgomez2000"

tomas.l.gomez@...> wrote: >

> Look at your last graph. There is a peak around 3.1. This is the

> "76 seconds error" (240 seconds divided by 3.1 is approximately

> equal to 76 seconds). My mount also suffers from this problem

> and, since I had the ST-7, I bought an AO-7 unit. It is an

> expensive cure, but it has really helped solving the problem.

>

> My OTA is an 8-inch Newton f/5. Most of the times I can find

> a guiding star bright enough to guide with 1 sec exposures

> (without rotating the camera), and very often I can take shorter

> exposures for the guiding chip. Then the guiding is quite good.

>

> I would really like to have my mount fixed, but I am afraid that

> if I start trying to tune it, I will spend endless hours in

> the job, and I am afraid it might end up in a worse condition

> that it is now!

>

> Anyway, the AO-7 is not the perfect cure: since the guiding

> chip is behind the filter, using a narrow band filter will

> force you to use long integration times for the guiding.

>

>

>

> --- In Losmandy_users@yahoogroups.com, "sdufoer" sdufoer@> wrote:

> >

> > Hello,

> >

> > For the G11 PE problem I posted a week ago. I have run a pempro

> > analysis on my G11. The PE of CCDsoft and the PE that pempro has

> > generated are very different. Do someone knows why?

> >

> > You can find the pempro results of my losmandy G11 here:

> > ccdware.infopop.cc/eve/forums/a/tpc/f/401101098/m/7501039891

> >

> > regards,

> > Sjoerd Dufoer

> >

>







----------------------------

#31644 Dec 3, 2006

Eric,



Yes, maybe you are right, but I think you have to understand our

disappointment. When I told the people that I bought a G11, everybody

said that it was the best of the best. Yes, maybe for visual

observing, but for CCD astrophotography it's not very accurate out of

the box. Maybe my mount can be cured. I'm working on different

solutions right now, but I have bought the G11 because of it's

reputation. Last year, I screwed my EQ6 up because I had probs with

it. The last thing I wanted was a recurrence of that story.



I bought a mount because I trusted that it would work. I don't care

that the PE curve is a nice sinus of +-20 arcsec. If it's smooth it's

ok for me. My idea of the hobby is to be buzy with the heaven. Not

the mount. I already spend a lot of clear nights with just the mount.

In belgium there are not so many clear nights. So it takes a lot of

time until you can actually use the mount after all that trail and

erroring.



Soit, I guess you're right. If you want quality without gambling you

have to go with the bigger guys. I accepted my situation. I learned

something and that is that the G11 is a do it yourself mount and has a

lot of quality differences.



BTW: thanks for your site and the tips. I already had a look and it

seemed very usuable to me. My plan is now to search for a good new

worm and install it. I also think that programming the pec with

pempro can help something.



regards,

Sjoerd

--- In Losmandy_users@yahoogroups.com, "Eric Benson" ebenson@...> wrote:

>

> Oh boy, here we go again....two more not especially satisfied G11

> users.

>

> Sjoerd, Tomas,

>

> Your mounts can be cured, but it will take some time and effort on

> your part. (OK it could be a lot of time and effort but this is a

> hobby, it's supposed to be fun ;) otherwise ponny up for some more

> expensive alternatives: MI250, AP900, AP1200, Paramount... The AO-7

> is a good "cheap" band-aid solution (ask LX200 users!!!) but for some

> it has to many constraints (e.g. need dual chip SBIG camera, long

> image train, behind filters as mentioned etc.)

>

> Look in the files section for a document by Astrokattner about the

> 76sec problem.

> See this page on my website for a run down of what modifications did

> what for my G11:

> www.freewebs.com/ebenson/G11tracking.htm

>

> It really helps if you scale your graphs for some of us (me at least)

> to help diagnose your mount. Make the vertical axis in arcsec and the

> horizontal in seconds or minutes, but not much longer than 2 worms

> cycles. You can stack the data vertically if you have alot of cycles,

> see this chart for example:

> www.freewebs.com/ebenson/G11%20Tracking/PemPro-2006-04-09-

> 015834.png

> I probably should put instructions on how to do this in Excel on my

> website.

>

> The most likely culprits in the G11 drive system are:

> (BTW I dont think that Losmandy can/is willing to fix all these

> problems at this time. IMO they should have an optional part, more

> expensive would be OK, that would solve this stuff for good, anyways

> back to reality...)

>

> #1 worm bearing blocks pinching ball bearings (the bearing pocket

> goes out of round when tightened)

> #2 rough ball bearings (replace with higher quality bearings)

> #3 bearing block misalignment (causing pinching)

> #4 motor-worm alignement (sometimes called Oldham coupler alignment)

> #5 high-precision worm not being up to snuff (I had to buy a new one!)

>

> The Oldham coupler gets a bad wrap since it is "blamed" for being

> misaligned. The coupler is not aligned, it just happens to sit in

> between two parts that need to be aligned, it provides for some

> flexibility when the gear box shaft and worm are not coaxial. The

> gear box shaft can be aligned a little bit in the vertical (wrt the

> mounting plate), almost none in the horizontal. The worm can be

> aligned none in the vertical and a bit in the horizontal but at the

> cost of not choosing the gear mesh you might want.

>

> Once you "fix" these problems you can look at replacing the Oldham

> coupler with a Helical coupler, some have had success, I havent

> myself so far but I am hoping to try it again some time soon. But

> again, I dont recommend you mess with replacing the coupler until you

> get everything else solved, the other issues are much more important

> tracking errorwise, IMHO.

>

> The mount can be made to perform (see some of my images at

> 0.63"/pixel), although it seems it needs readjustment every once in a

> while. Recently I had lousy tracking and the cause was DEC worm block

> misalignment plus so-so polar alignment. I would have hated to see

> the tracking if it would have been the RA blocks out of whack!!! BTW

> I dont know how they got that way, they were well aligned at the

> start of the summer and I never touched them, I wonder if the

> alignment can migrate with temperature cycling or is it continuous

> use?

>

> Eric Benson

> www.freewebs.com/ebenson

>







----------------------------

#31648 Dec 4, 2006

I don't know why they would say that. The G11 is best thought of as

the low end of the high end. If you're still messing around with

Chinese imports it could be viewed as best of the best.



There's really nothing quite like it in its load class and price.



regards Greg N

--- In Losmandy_users@yahoogroups.com, "sdufoer" sdufoer@...> wrote:

>

> Eric,

>

> Yes, maybe you are right, but I think you have to understand our

> disappointment. When I told the people that I bought a G11, everybody

> said that it was the best of the best.



----------------------------

#33346 Jun 25, 2007

See message 31208. for details of Dove Web's mods. Charles



----------------------------

#33349 Jun 26, 2007

From what I have seen and read, both GM8 and G11 use the same worm,

the same worm blocks, the same coupler and the same servos.

If the PE is essentially coming from the the worm, why is there such a

difference (as reported by this group) between both mounts (.4-5 for

the G11 and .12-15 for the GM8)?

What else is contributing?



Olivier



----------------------------

#33351 Jun 26, 2007

Hi Olivier,



I do not know. The only thing I know is that the G11 has a 360 teeth

gear and the GM-8 has a 180 teeth gear adn as you say the same worm,

the same ball bearings and the same blocks for the ball bearings.



Maybe the slower speed of the worm in the GM-8 ? It takes 8 minutes in

the GM-8 top make 1 revolution and the G11 it takes 4 minutes for 1

worm revolution.



saludos Rainer



>

> From what I have seen and read, both GM8 and G11 use the same worm,

> the same worm blocks, the same coupler and the same servos.

> If the PE is essentially coming from the the worm, why is there such a

> difference (as reported by this group) between both mounts (.4-5 for

> the G11 and .12-15 for the GM8)?

> What else is contributing?

>

> Olivier

>



----------------------------

#33353 Jun 26, 2007

Olivier,



The GM8 and G11 worms are no where close to the same...The GM8 has

2.812", 180 tooth where the the G11 has a 5.625"", 360 tooth.



In theory (everything being the same except gear dia.) the PE will

double as the gear dia is halfed. Its easy to see why there is such a

difference in PE from a 2.8" gear vs. a 5.6".



Here's an excellent discription (by Chris Heapy, a Master Machinist)

of

the tollerances required to manufacture a +/- 5 arc sec gear realative

to gear diamiter.



kansai.anesth.or.jp/gijutu/kousaku/easyweb.easynet.co.uk/chrish

/eqnotes.htm#wga



Scott O.

Las Vegas, NV.

> From what I have seen and read, both GM8 and G11 use the same worm,

> the same worm blocks, the same coupler and the same servos.

> If the PE is essentially coming from the the worm, why is there

such a > difference (as reported by this group) between both mounts (.4-5 for

> the G11 and .12-15 for the GM8)?

> What else is contributing?

>

> Olivier

>



----------------------------

#33354 Jun 26, 2007

Could the problem be that people are not distinguishing between the worm and the

wheel? The worm drives the wheel. The wheel may be out-of-round by tiny amounts;

in which case the speed of the worm can compensate through PEC. Is the wheel

size in a G11 different from a G8?







Greg C.







[Non-text portions of this message have been removed]



----------------------------

#33356 Jun 26, 2007

Hi Scott O.,



The worms for the GM-8 and the G11 ARE the SAME.



I have running 2 RS-Wormblocks which I made for my GM-8 on a CG11

that is about 11 years old.



The modul of the GM-8 and G11 gear e.g. the big gear with 180 or 360

teeth is 0.4 as far as I have been able to interpolate.



Modul 0.4 multiplied by 360 teeth gives a diameter of about 144mm ~

5.669" or 5.625" as it is specified on the Losmandy site.



The GM-8 is specified with a diameter of 2.812" having 180 teeth that

gives also roughly a modul of 0.4 e.g. 180 multiplied by 0.4 = 72mm ~

2.834"



saludos Rainer



>

> Olivier,

>

> The GM8 and G11 worms are no where close to the same...The GM8 has

> 2.812", 180 tooth where the the G11 has a 5.625"", 360 tooth.

>

> In theory (everything being the same except gear dia.) the PE will

> double as the gear dia is halfed. Its easy to see why there is such

a > difference in PE from a 2.8" gear vs. a 5.6".

>

> Here's an excellent discription (by Chris Heapy, a Master

Machinist) > of

> the tollerances required to manufacture a +/- 5 arc sec gear

realative > to gear diamiter.

>

>

kansai.anesth.or.jp/gijutu/kousaku/easyweb.easynet.co.uk/chrish > /eqnotes.htm#wga

>

> Scott O.

> Las Vegas, NV.

>



----------------------------

#33357 Jun 26, 2007

Hi Rainer,



Forgive me...You are correct that the WORM(s) are the same.



He asked why there's such a difference in PE and it is directly

linked to the worm gear dia. which is what I was trying to point out.



I guess I should have said WORM GEAR and not WORM:-)



This whole conversation makes me want to find the WORM in the bottom

of a bottle of Tequila:-)





Scott O.

Las Vegas, NV.

> Hi Scott O.,

>

> The worms for the GM-8 and the G11 ARE the SAME.

>

> I have running 2 RS-Wormblocks which I made for my GM-8 on a CG11

> that is about 11 years old.

>

> The modul of the GM-8 and G11 gear e.g. the big gear with 180 or

360 > teeth is 0.4 as far as I have been able to interpolate.

>

> Modul 0.4 multiplied by 360 teeth gives a diameter of about 144mm ~

> 5.669" or 5.625" as it is specified on the Losmandy site.

>

> The GM-8 is specified with a diameter of 2.812" having 180 teeth

that > gives also roughly a modul of 0.4 e.g. 180 multiplied by 0.4 = 72mm

~ > 2.834"

>

> saludos Rainer







----------------------------

#33358 Jun 26, 2007

Hi Scott,



Forgiven :-), but you just made another mistake :-)



There is NO WORM at the bottom of a TEQUILA bottle !



The WORM is at the bottom of a MEZCAL bottle !



TEQUILA and MEZCAL are absolutely 2 different alcoholic beverages.



TEQUILA 100% AGAVE is made of the agave plant called AGAVE WEBER AZUL

and the MEZCAL is made from avariety of agave plants more commonly

named Maguey.



The taste is also very different.



Here you can see report of how MEZCAL is produced



www.rsfotografia.com/2English/MenuEnglish.html



CHEERS :-)



saludos Rainer





>

> Hi Rainer,

>

> Forgive me...You are correct that the WORM(s) are the same.

>

> He asked why there's such a difference in PE and it is directly

> linked to the worm gear dia. which is what I was trying to point

out. >

> I guess I should have said WORM GEAR and not WORM:-)

>

> This whole conversation makes me want to find the WORM in the

bottom > of a bottle of Tequila:-)

>

>

> Scott O.

> Las Vegas, NV.

>

> > Hi Scott O.,

> >

> > The worms for the GM-8 and the G11 ARE the SAME.

> >

> > I have running 2 RS-Wormblocks which I made for my GM-8 on a CG11

> > that is about 11 years old.

> >

> > The modul of the GM-8 and G11 gear e.g. the big gear with 180 or

> 360

> > teeth is 0.4 as far as I have been able to interpolate.

> >

> > Modul 0.4 multiplied by 360 teeth gives a diameter of about 144mm

~ > > 5.669" or 5.625" as it is specified on the Losmandy site.

> >

> > The GM-8 is specified with a diameter of 2.812" having 180 teeth

> that

> > gives also roughly a modul of 0.4 e.g. 180 multiplied by 0.4 =

72mm > ~

> > 2.834"

> >

> > saludos Rainer

>



----------------------------

#33359 Jun 26, 2007

Rainer,



Damn, I'm just gonna quit for the week! Its been 16 years since I had

a drink so My memory of those days is foggy...



I'm gonna make the rest of my mistakes in private:-) Signing off...



Scott O.

>

> Hi Scott,

>

> Forgiven :-), but you just made another mistake :-)

>

> There is NO WORM at the bottom of a TEQUILA bottle !

>

> The WORM is at the bottom of a MEZCAL bottle !

>

> TEQUILA and MEZCAL are absolutely 2 different alcoholic beverages.

>

> TEQUILA 100% AGAVE is made of the agave plant called AGAVE WEBER

AZUL > and the MEZCAL is made from avariety of agave plants more commonly

> named Maguey.

>

> The taste is also very different.

>

> Here you can see report of how MEZCAL is produced

>

> www.rsfotografia.com/2English/MenuEnglish.html

>

> CHEERS :-)

>

> saludos Rainer

>

>

>

> >

> > Hi Rainer,

> >

> > Forgive me...You are correct that the WORM(s) are the same.

> >

> > He asked why there's such a difference in PE and it is directly

> > linked to the worm gear dia. which is what I was trying to point

> out.

> >

> > I guess I should have said WORM GEAR and not WORM:-)

> >

> > This whole conversation makes me want to find the WORM in the

> bottom

> > of a bottle of Tequila:-)

> >

> >

> > Scott O.

> > Las Vegas, NV.

> >

> > > Hi Scott O.,

> > >

> > > The worms for the GM-8 and the G11 ARE the SAME.

> > >

> > > I have running 2 RS-Wormblocks which I made for my GM-8 on a

CG11 > > > that is about 11 years old.

> > >

> > > The modul of the GM-8 and G11 gear e.g. the big gear with 180

or > > 360

> > > teeth is 0.4 as far as I have been able to interpolate.

> > >

> > > Modul 0.4 multiplied by 360 teeth gives a diameter of about

144mm > ~

> > > 5.669" or 5.625" as it is specified on the Losmandy site.

> > >

> > > The GM-8 is specified with a diameter of 2.812" having 180

teeth > > that

> > > gives also roughly a modul of 0.4 e.g. 180 multiplied by 0.4 =

> 72mm

> > ~

> > > 2.834"

> > >

> > > saludos Rainer

> >

>



----------------------------

#33360 Jun 26, 2007

Scott,

Yes both gears are different in diameter and number of teeth.

However we are talking about a PERIODIC ERROR that is measured with

respect to the WORM revolution. When using Pempro to graph the PE over

several period, the curves, once compensated for drift, do align more

or less and show a periodicity in behavior.

I fail to see why the gear would have a periodic impact since it will

take nearly 24 hours for one full gear revolution.

Therefore, while irregularities in the gear will contribute to an

a-periodic error, the gear itself should not contribute to the

periodic part of the error. And from there, I am still wondering where

the difference between the two mounts comes from?



Olivier





--- In Losmandy_users@yahoogroups.com, "soates4616" soates4616@...>

wrote: >

> Hi Rainer,

>

> Forgive me...You are correct that the WORM(s) are the same.

>

> He asked why there's such a difference in PE and it is directly

> linked to the worm gear dia. which is what I was trying to point out.

>

> I guess I should have said WORM GEAR and not WORM:-)

>

> This whole conversation makes me want to find the WORM in the bottom

> of a bottle of Tequila:-)

>

>

> Scott O.

> Las Vegas, NV.

>

> > Hi Scott O.,

> >

> > The worms for the GM-8 and the G11 ARE the SAME.

> >

> > I have running 2 RS-Wormblocks which I made for my GM-8 on a CG11

> > that is about 11 years old.

> >

> > The modul of the GM-8 and G11 gear e.g. the big gear with 180 or

> 360

> > teeth is 0.4 as far as I have been able to interpolate.

> >

> > Modul 0.4 multiplied by 360 teeth gives a diameter of about 144mm ~

> > 5.669" or 5.625" as it is specified on the Losmandy site.

> >

> > The GM-8 is specified with a diameter of 2.812" having 180 teeth

> that

> > gives also roughly a modul of 0.4 e.g. 180 multiplied by 0.4 = 72mm

> ~

> > 2.834"

> >

> > saludos Rainer

>







----------------------------

#33364 Jun 26, 2007

Thinking back on what Scott said, it makes sense. With the same worm

and the same gear tooth pitch, a gear with 2X the diameter will show

half the angular delta caused by an irregular worm than a 1X diameter

gear. And this explains why the GM8 should have nominally twice the PE

of the G11.

This is helpful in setting the correct expectations of any wormblock

improvement for the GM8: unless one happens to have a very very good

worm, a GM8 PE will not likely be better than .6-7 arc sec . This also

does not mean it cannot be guided out, it will just be a little bit

harder than with a G11.

Olivier



--- In Losmandy_users@yahoogroups.com, "olivierfp" oprache@...> wrote:

>

> Scott,

> Yes both gears are different in diameter and number of teeth.

> However we are talking about a PERIODIC ERROR that is measured with

> respect to the WORM revolution. When using Pempro to graph the PE over

> several period, the curves, once compensated for drift, do align more

> or less and show a periodicity in behavior.

> I fail to see why the gear would have a periodic impact since it will

> take nearly 24 hours for one full gear revolution.

> Therefore, while irregularities in the gear will contribute to an

> a-periodic error, the gear itself should not contribute to the

> periodic part of the error. And from there, I am still wondering where

> the difference between the two mounts comes from?

>

> Olivier

>

>

> --- In Losmandy_users@yahoogroups.com, "soates4616" soates4616@>

> wrote:

> >

> > Hi Rainer,

> >

> > Forgive me...You are correct that the WORM(s) are the same.

> >

> > He asked why there's such a difference in PE and it is directly

> > linked to the worm gear dia. which is what I was trying to point out.

> >

> > I guess I should have said WORM GEAR and not WORM:-)

> >

> > This whole conversation makes me want to find the WORM in the bottom

> > of a bottle of Tequila:-)

> >

> >

> > Scott O.

> > Las Vegas, NV.

> >

> > > Hi Scott O.,

> > >

> > > The worms for the GM-8 and the G11 ARE the SAME.

> > >

> > > I have running 2 RS-Wormblocks which I made for my GM-8 on a CG11

> > > that is about 11 years old.

> > >

> > > The modul of the GM-8 and G11 gear e.g. the big gear with 180 or

> > 360

> > > teeth is 0.4 as far as I have been able to interpolate.

> > >

> > > Modul 0.4 multiplied by 360 teeth gives a diameter of about 144mm ~

> > > 5.669" or 5.625" as it is specified on the Losmandy site.

> > >

> > > The GM-8 is specified with a diameter of 2.812" having 180 teeth

> > that

> > > gives also roughly a modul of 0.4 e.g. 180 multiplied by 0.4 = 72mm

> > ~

> > > 2.834"

> > >

> > > saludos Rainer

> >

>



----------------------------

#33366 Jun 26, 2007

Just for the sake of this argument ( the guide part ) I've just exposed 16 minutes on a GM8 carrying an FLT-110 (TEC LENS), a Skywatcher 80ED (same as Orion 80ED) 2 DUP's, 1 ATIK 16HR,1Atik 16IC, 1 Robofocus, 1 FLI CFW-8 plus filters and 2 WO 2" extenders. If needed I can send a link to the original image. The PE of the mount is 8 arc sec and I expect it to get a bit better ater some real fine tuning.







Regards,







Canela



---------------



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com] On Behalf Of olivierfp

Sent: ter.a-feira, 26 de Junho de 2007 21:39

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: G8 & G11 PE source explained







Thinking back on what Scott said, it makes sense. With the same worm

and the same gear tooth pitch, a gear with 2X the diameter will show

half the angular delta caused by an irregular worm than a 1X diameter

gear. And this explains why the GM8 should have nominally twice the PE

of the G11.

This is helpful in setting the correct expectations of any wormblock

improvement for the GM8: unless one happens to have a very very good

worm, a GM8 PE will not likely be better than .6-7 arc sec . This also

does not mean it cannot be guided out, it will just be a little bit

harder than with a G11.

Olivier

--- In Losmandy_users@yahoogroups.com mailto:Losmandy_users%40yahoogroups.com> , "olivierfp" oprache@...> wrote:

>

> Scott,

> Yes both gears are different in diameter and number of teeth.

> However we are talking about a PERIODIC ERROR that is measured with

> respect to the WORM revolution. When using Pempro to graph the PE over

> several period, the curves, once compensated for drift, do align more

> or less and show a periodicity in behavior.

> I fail to see why the gear would have a periodic impact since it will

> take nearly 24 hours for one full gear revolution.

> Therefore, while irregularities in the gear will contribute to an

> a-periodic error, the gear itself should not contribute to the

> periodic part of the error. And from there, I am still wondering where

> the difference between the two mounts comes from?

>

> Olivier

>

>

> --- In Losmandy_users@yahoogroups.com mailto:Losmandy_users%40yahoogroups.com> , "soates4616" soates4616@>

> wrote:

> >

> > Hi Rainer,

> >

> > Forgive me...You are correct that the WORM(s) are the same.

> >

> > He asked why there's such a difference in PE and it is directly

> > linked to the worm gear dia. which is what I was trying to point out.

> >

> > I guess I should have said WORM GEAR and not WORM:-)

> >

> > This whole conversation makes me want to find the WORM in the bottom

> > of a bottle of Tequila:-)

> >

> >

> > Scott O.

> > Las Vegas, NV.

> >

> > > Hi Scott O.,

> > >

> > > The worms for the GM-8 and the G11 ARE the SAME.

> > >

> > > I have running 2 RS-Wormblocks which I made for my GM-8 on a CG11

> > > that is about 11 years old.

> > >

> > > The modul of the GM-8 and G11 gear e.g. the big gear with 180 or

> > 360

> > > teeth is 0.4 as far as I have been able to interpolate.

> > >

> > > Modul 0.4 multiplied by 360 teeth gives a diameter of about 144mm ~

> > > 5.669" or 5.625" as it is specified on the Losmandy site.

> > >

> > > The GM-8 is specified with a diameter of 2.812" having 180 teeth

> > that

> > > gives also roughly a modul of 0.4 e.g. 180 multiplied by 0.4 = 72mm

> > ~

> > > 2.834"

> > >

> > > saludos Rainer

> >

>











[Non-text portions of this message have been removed]







----------------------------

#33369 Jun 26, 2007

Jose,

This is a nice number: is it before or after PEC?

I got .8 arc-sec after PEC but noticed the next day that the motor and

worm axes were offset. Since then, no luck getting out between the

waxing moon, the short nights and having to work the next morning).

Obviously I still have some tweaking to do with a semi one-piece worm

holder I got last Friday. More on this later.

Olivier



--- In Losmandy_users@yahoogroups.com, "jose canela" jcanela@...> wrote:

>

> Just for the sake of this argument ( the guide part ) I've just

exposed 16 minutes on a GM8 carrying an FLT-110 (TEC LENS), a

Skywatcher 80ED (same as Orion 80ED) 2 DUP's, 1 ATIK 16HR,1Atik 16IC,

1 Robofocus, 1 FLI CFW-8 plus filters and 2 WO 2" extenders. If needed

I can send a link to the original image. The PE of the mount is 8 arc

sec and I expect it to get a bit better ater some real fine tuning.

>

>

>

> Regards,

>

>

>

> Canela

>

>



----------------------------

#33376 Jun 27, 2007

I always take PE errors without PEC. If PEC is introduced then the PE will not be "natural" and therefore it becomes some sort of "guided" PE.







I don't even use PEC. I'd rather spend some time messing with the mount mechanically in order to make it better by nature than correcting errors with PEC... besides you'll need to guide anyway so if the PE is low enough guiding will take care of the rest.







Regards,







Jos. Canela



---------------



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com] On Behalf Of olivierfp

Sent: quarta-feira, 27 de Junho de 2007 1:35

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: G8 & G11 PE source explained







Jose,

This is a nice number: is it before or after PEC?

I got .8 arc-sec after PEC but noticed the next day that the motor and

worm axes were offset. Since then, no luck getting out between the

waxing moon, the short nights and having to work the next morning).

Obviously I still have some tweaking to do with a semi one-piece worm

holder I got last Friday. More on this later.

Olivier

--- In Losmandy_users@yahoogroups.com mailto:Losmandy_users%40yahoogroups.com> , "jose canela" jcanela@...> wrote:

>

> Just for the sake of this argument ( the guide part ) I've just

exposed 16 minutes on a GM8 carrying an FLT-110 (TEC LENS), a

Skywatcher 80ED (same as Orion 80ED) 2 DUP's, 1 ATIK 16HR,1Atik 16IC,

1 Robofocus, 1 FLI CFW-8 plus filters and 2 WO 2" extenders. If needed

I can send a link to the original image. The PE of the mount is 8 arc

sec and I expect it to get a bit better ater some real fine tuning.

>

>

>

> Regards,

>

>

>

> Canela

>

>











[Non-text portions of this message have been removed]



----------------------------

#34456 Oct 7, 2007

I m the French Losmandy supplier

_www.ovision.com_ (www.ovision.com)



have a try see the file on PE on G 11



Franck Valbousquet























[Non-text portions of this message have been removed]



----------------------------

#34476 Oct 7, 2007

Thanks Ken,

I'm sure I had visited that site before, but I don't recall seeing the

PE graphs (faulty memory or they're new!). The sampling rate he used was

a little slow (~6 sec) so any fast stuff will be a little washed out,

however the raw curves do look smoother than mine. From the MI website:

"MI-250 RA and DEC worm/gears are diamond lapped"

So perhaps a new project for this winter is coming up!



What I'm really after is the ability to guide on faint guide stars

(hence >2sec integrations) at high resolution (EFL=2800mm). I find that

setting my guider exposure to greater than ~4 sec makes guiding actually

worse than less signal and more frequent updates.



Searching the archives for "lapping" I found that a user GlenLRay had

done this back in 2004 (see PE and RA Shift Plots in the files section),

however I really can't tell what the improvement was since his data is

severely contaminated by the 76er !!! I guess he was unknowingly trying

to fix the wrong problem, I hope I don't end up doing the same!

Looking some more I see f_holub posted a nice result (see

PE-lapping.pdf in files root) however I still see 2+" jumps over 10sec,

which would still be annoying.



Eric



P.S. Rainer, I must apologize for misspelling your name in my previous post.





astrokattner wrote: > Also, it could be the MI250 has less noise using the same components

> (other than the worm) because it keeps all these components in a

> straight line...

>

>

> --- In Losmandy_users@yahoogroups.com, "astrokattner" kattnerk@...>

> wrote:

>

>> Hi Eric,

>>

>> See here:

>>

>> www.horizontalheavens.com/MI-250.htm

>>

>> And follow the link to PE performance. This guy has an MI250 and

>>

> he

>

>> shows a PEMPro PE curve for his mount. You might find it

>>

> interesting

>

>> for comparison. Here's why. Look at the picture of the worm block

>> on the MI250 on this guy's site. You can see it uses the same

>>

> motor,

>

>> same oldham and same gearbox as the G11, however, the gear box,

>>

> motor

>

>> and worm are all part of one assembly that adjusts toward the gear

>> with set screws (Rainer's design does this too). The worm and gear

>> are different from the G11. The important point here is that we

>>

> can

>

>> take certain components of the gear train out of the equation when

>> comparing to yours. If your PE is noiser than this guy's PE, then

>> one could conclude it's due to the worm and gear implementation

>> because all other components are the same - gear, motor and

>>

> coupler.

>

>> Some food for thought...

>>

>> Ken

>>

>>

>>

>>

>> --- In Losmandy_users@yahoogroups.com, Eric Benson ebenson@>

>> wrote:

>>

>>> Hi all,

>>> I have been trying to improve the tracking of my G11 since I got

>>>

>> it. It

>>

>>> is good now but of course I always want more so I have wondered

>>>

>> about

>>

>>> reducing the "fast noise" that seems to be my limiting factor at

>>>

>> this

>>

>>> point. I considered the noise to come from:

>>> A) main gear

>>> b) worm

>>> c) coupler

>>> d) gear box

>>> e) motor

>>>

>>> My tests with Oldham and helical couplers tell me that if

>>>

> properly

>

>>> aligned neither affect the main noise that causes 75% of my

>>>

>> tracking

>>

>>> problems.

>>> Rainier (or anybody else!), did you see a noticeable improvement

>>>

>> after

>>

>>> lapping the worm+main gear in terms of high frequency tracking

>>>

>> errors?

>>

>>> Or do you think the gearbox is the main noise source, if so is

>>>

>> there a

>>

>>> better gear box to try? Does anyone have any experience with the

>>>

>> Maxon

>>

>>> motors, are they "quieter", I understand they have more torque

>>>

> but

>

>> I

>>

>>> don't have motor stall problems so...

>>>

>>> Thanks,

>>> Eric

>>>

>>> BTW with John (below) saying he saw no improvement with what

>>>

> looks

>

>> (to

>>

>>> me at least) like to be a brass worm, I wonder if the gear box is

>>>

>> my

>>

>>> culprit.

>>>

>>>

>>> Rainer wrote:

>>>

>>>> Hi,

>>>>

>>>> Interesting but honestly I do not see how by just making an

>>>>

>> allegedly

>>

>>>> more precise worm the problem with the 76 seconds should

>>>>

>> disappear.

>>

>>>> It has been proven by some of the members here that the 76

>>>>

> error

>

>>>> comes from the ball bearings and as long as you only use radial

>>>>

>> ball

>>

>>>> bearings or maybe angular radial ball bearings everything

>>>>

> depends

>

>> of

>>

>>>> the quality of those.

>>>>

>>>> >From my point of view if you use also a set of axial ball

>>>>

>> bearings or

>>

>>>> thrust bearings then you can get rid of the 76 second error. OK

>>>>

>> The

>>

>>>> thrust bearings have to be exceptionally clean on the running

>>>>

>> surface.

>>

>>>> You can achieve the same by just lapping the original worm

>>>>

>> against

>>

>>>> the gear using some oil and very fine grinding powder. The

>>>>

>> lapping

>>

>>>> takes about 3-4 hours for each axis and can be done during a

>>>>

>> cloudy

>>

>>>> season.

>>>>

>>>>

>>>>

>>>>







----------------------------

#34504 Oct 8, 2007

Hi, last weekend i made my first try to measure PE with PEMPRO but

don.t know how to interpret the results. Can somebody help me with

this?



5 worm cycles with PEC off

farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg



Grapf of PE frequency spectrum PEC off

farm3.static.flickr.com/2025/1518454564_e2287991dc_o.jpg



2 worm cycles with PEC on

farm3.static.flickr.com/2065/1517603877_6dec23136b_o.jpg



Grapf of PE frequency spectrum PEC on

farm3.static.flickr.com/2291/1517603931_272ef1ff39_o.jpg



Peak to peak before and after PEC

farm3.static.flickr.com/2168/1518454768_4dd9c7eed2_o.jpg



What do you think about this?



Thanks in advance and clear skies, Florencio



----------------------------

#34505 Oct 8, 2007

frodil620206 wrote: > Hi, last weekend i made my first try to measure PE with PEMPRO but

> don.t know how to interpret the results. Can somebody help me with

> this?

>

> 5 worm cycles with PEC off

> farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg

>



Each warm cycle is graphed in a different color. While your screenshot

shows is all the worm cycles are in phase (good), and the PE ranges from

about +17 arc seconds (from 10 to 27 on the graph) and -10 arc seconds

(from 10 to 0 on the graph). The current is very smooth, with no sudden

jumps, and is a good candidate for PEC.



--- Mike

--



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com



----------------------------

#34506 Oct 8, 2007

Thanks Mike, i did PEC, the last three images shows the result, but

i had no chance to use the mount after that so i can not say

anything about the performance.



What about the 76 secs error? Can it be diagnose from this data?



Regards, Florencio

--- In Losmandy_users@yahoogroups.com, Mike Dodd mike@...> wrote:

>

> frodil620206 wrote:

> > Hi, last weekend i made my first try to measure PE with PEMPRO

but

> > don.t know how to interpret the results. Can somebody help me

with

> > this?

> >

> > 5 worm cycles with PEC off

> > farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg

> >

>

> Each warm cycle is graphed in a different color. While your

screenshot

> shows is all the worm cycles are in phase (good), and the PE

ranges from

> about +17 arc seconds (from 10 to 27 on the graph) and -10 arc

seconds

> (from 10 to 0 on the graph). The current is very smooth, with no

sudden

> jumps, and is a good candidate for PEC.

>

> --- Mike

> --

>

> Mike Dodd

> Montpelier, VA USA

> astronomy.mdodd.com

>



----------------------------

#34507 Oct 8, 2007

Your 5 worm cycles with PEC off look quite good. The frequency

distribution for these 5 cycles does not show the 76 second error,

however, the two cycles you collected with PEC on have a frequency

distribution that shows a hump at the 76-78 second point (the first

hump to the left of the one second mark) - which is a strange

result. I would try and collect some more data with PEC on and see

how it fares. Two cycles isn't very much.







--- In Losmandy_users@yahoogroups.com, "frodil620206"

frodil620206@...> wrote: >

> Hi, last weekend i made my first try to measure PE with PEMPRO but

> don.t know how to interpret the results. Can somebody help me with

> this?

>

> 5 worm cycles with PEC off

> farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg

>

> Grapf of PE frequency spectrum PEC off

> farm3.static.flickr.com/2025/1518454564_e2287991dc_o.jpg

>

> 2 worm cycles with PEC on

> farm3.static.flickr.com/2065/1517603877_6dec23136b_o.jpg

>

> Grapf of PE frequency spectrum PEC on

> farm3.static.flickr.com/2291/1517603931_272ef1ff39_o.jpg

>

> Peak to peak before and after PEC

> farm3.static.flickr.com/2168/1518454768_4dd9c7eed2_o.jpg

>

> What do you think about this?

>

> Thanks in advance and clear skies, Florencio

>



----------------------------

#34508 Oct 8, 2007

Florencio,

If there is a 76s component it is buried by the much larger amplitude

fundamental. So I don't think you need to worry about it. What I find a

little disconcerting is the amplitude of the PE, 23" is really big, have

you double checked the pixel scale? (what is the focal length of your

scope and which camera are you using?) Does this mount have a new "high

precision" worm? Otherwise your curve is very smooth and should also

respond well to autoguiding and/or PEC



Eric



frodil620206 wrote: > Thanks Mike, i did PEC, the last three images shows the result, but

> i had no chance to use the mount after that so i can not say

> anything about the performance.

>

> What about the 76 secs error? Can it be diagnose from this data?

>

> Regards, Florencio

>

> --- In Losmandy_users@yahoogroups.com, Mike Dodd mike@...> wrote:

>

>> frodil620206 wrote:

>>

>>> Hi, last weekend i made my first try to measure PE with PEMPRO

>>>

> but

>

>>> don.t know how to interpret the results. Can somebody help me

>>>

> with

>

>>> this?

>>>

>>> 5 worm cycles with PEC off

>>> farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg

>>>

>>>

>> Each warm cycle is graphed in a different color. While your

>>

> screenshot

>

>> shows is all the worm cycles are in phase (good), and the PE

>>

> ranges from

>

>> about +17 arc seconds (from 10 to 27 on the graph) and -10 arc

>>

> seconds

>

>> (from 10 to 0 on the graph). The current is very smooth, with no

>>

> sudden

>

>> jumps, and is a good candidate for PEC.

>>

>> --- Mike

>> --

>>

>> Mike Dodd

>> Montpelier, VA USA

>> astronomy.mdodd.com

>>

>>

>

>

>

>







----------------------------

#34509 Oct 8, 2007

Hi Eric, thanks a lot. Yes i did check the pixel scale and think is

ok. I used an Orion 80ED 600mm scope and a DSI I camera. I suppose

the mount has the high precision worm because i received it from

Losmandy only a month ago, but i don.t know.



Regards, Florencio



--- In Losmandy_users@yahoogroups.com, Eric Benson ebenson@...>

wrote: >

> Florencio,

> If there is a 76s component it is buried by the much larger

amplitude > fundamental. So I don't think you need to worry about it. What I

find a > little disconcerting is the amplitude of the PE, 23" is really

big, have > you double checked the pixel scale? (what is the focal length of

your > scope and which camera are you using?) Does this mount have a

new "high > precision" worm? Otherwise your curve is very smooth and should

also > respond well to autoguiding and/or PEC

>

> Eric

>

> frodil620206 wrote:

> > Thanks Mike, i did PEC, the last three images shows the result,

but > > i had no chance to use the mount after that so i can not say

> > anything about the performance.

> >

> > What about the 76 secs error? Can it be diagnose from this data?

> >

> > Regards, Florencio

> >

> > --- In Losmandy_users@yahoogroups.com, Mike Dodd mike@> wrote:

> >

> >> frodil620206 wrote:

> >>

> >>> Hi, last weekend i made my first try to measure PE with PEMPRO

> >>>

> > but

> >

> >>> don.t know how to interpret the results. Can somebody help me

> >>>

> > with

> >

> >>> this?

> >>>

> >>> 5 worm cycles with PEC off

> >>> farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg

> >>>

> >>>

> >> Each warm cycle is graphed in a different color. While your

> >>

> > screenshot

> >

> >> shows is all the worm cycles are in phase (good), and the PE

> >>

> > ranges from

> >

> >> about +17 arc seconds (from 10 to 27 on the graph) and -10 arc

> >>

> > seconds

> >

> >> (from 10 to 0 on the graph). The current is very smooth, with

no > >>

> > sudden

> >

> >> jumps, and is a good candidate for PEC.

> >>

> >> --- Mike

> >> --

> >>

> >> Mike Dodd

> >> Montpelier, VA USA

> >> astronomy.mdodd.com

> >>

> >>

> >

> >

> >

> >

>



----------------------------

#34511 Oct 8, 2007

Could it be the PEC induced the 76 sec error? Could it be part of the

problem, a software error?

Floyd

--- In Losmandy_users@yahoogroups.com, "astrokattner" kattnerk@...>

wrote: >

> Your 5 worm cycles with PEC off look quite good. The frequency

> distribution for these 5 cycles does not show the 76 second error,

> however, the two cycles you collected with PEC on have a frequency

> distribution that shows a hump at the 76-78 second point (the first

> hump to the left of the one second mark) - which is a strange

> result. I would try and collect some more data with PEC on and see

> how it fares. Two cycles isn't very much.

>

>

>

> --- In Losmandy_users@yahoogroups.com, "frodil620206"

> frodil620206@> wrote:

> >

> > Hi, last weekend i made my first try to measure PE with PEMPRO but

> > don.t know how to interpret the results. Can somebody help me with

> > this?

> >

> > 5 worm cycles with PEC off

> > farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg

> >

> > Grapf of PE frequency spectrum PEC off

> > farm3.static.flickr.com/2025/1518454564_e2287991dc_o.jpg

> >

> > 2 worm cycles with PEC on

> > farm3.static.flickr.com/2065/1517603877_6dec23136b_o.jpg

> >

> > Grapf of PE frequency spectrum PEC on

> > farm3.static.flickr.com/2291/1517603931_272ef1ff39_o.jpg

> >

> > Peak to peak before and after PEC

> > farm3.static.flickr.com/2168/1518454768_4dd9c7eed2_o.jpg

> >

> > What do you think about this?

> >

> > Thanks in advance and clear skies, Florencio

> >

>



----------------------------

#34513 Oct 8, 2007

Don't see how PEC could introduce the error - the error is

hardware/mechanically related. If the mount was bumped or something

changed with respect to the mount between the time the PE data was

gathered and the time the PEC was turned on, this could cause it. He

should just try and gather more PEC curves and see how it looks.

--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

>

> Could it be the PEC induced the 76 sec error? Could it be part of

the

> problem, a software error?

> Floyd

> --- In Losmandy_users@yahoogroups.com, "astrokattner" kattnerk@>

> wrote:

> >

> > Your 5 worm cycles with PEC off look quite good. The frequency

> > distribution for these 5 cycles does not show the 76 second

error,

> > however, the two cycles you collected with PEC on have a

frequency

> > distribution that shows a hump at the 76-78 second point (the

first

> > hump to the left of the one second mark) - which is a strange

> > result. I would try and collect some more data with PEC on and

see

> > how it fares. Two cycles isn't very much.

> >

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "frodil620206"

> > frodil620206@> wrote:

> > >

> > > Hi, last weekend i made my first try to measure PE with PEMPRO

but

> > > don.t know how to interpret the results. Can somebody help me

with

> > > this?

> > >

> > > 5 worm cycles with PEC off

> > > farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg

> > >

> > > Grapf of PE frequency spectrum PEC off

> > > farm3.static.flickr.com/2025/1518454564_e2287991dc_o.jpg

> > >

> > > 2 worm cycles with PEC on

> > > farm3.static.flickr.com/2065/1517603877_6dec23136b_o.jpg

> > >

> > > Grapf of PE frequency spectrum PEC on

> > > farm3.static.flickr.com/2291/1517603931_272ef1ff39_o.jpg

> > >

> > > Peak to peak before and after PEC

> > > farm3.static.flickr.com/2168/1518454768_4dd9c7eed2_o.jpg

> > >

> > > What do you think about this?

> > >

> > > Thanks in advance and clear skies, Florencio

> > >

> >

>







----------------------------

#34515 Oct 8, 2007

Thanks a lot, i will collect more data as soon as possible.



Best regads, Florencio



--- In Losmandy_users@yahoogroups.com, "astrokattner" kattnerk@...>

wrote: >

> Don't see how PEC could introduce the error - the error is

> hardware/mechanically related. If the mount was bumped or

something > changed with respect to the mount between the time the PE data was

> gathered and the time the PEC was turned on, this could cause it.

He > should just try and gather more PEC curves and see how it looks.

>

> --- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@> wrote:

> >

> > Could it be the PEC induced the 76 sec error? Could it be part

of > the

> > problem, a software error?

> > Floyd

> > --- In Losmandy_users@yahoogroups.com, "astrokattner" kattnerk@>

> > wrote:

> > >

> > > Your 5 worm cycles with PEC off look quite good. The

frequency > > > distribution for these 5 cycles does not show the 76 second

> error,

> > > however, the two cycles you collected with PEC on have a

> frequency

> > > distribution that shows a hump at the 76-78 second point (the

> first

> > > hump to the left of the one second mark) - which is a strange

> > > result. I would try and collect some more data with PEC on

and > see

> > > how it fares. Two cycles isn't very much.

> > >

> > >

> > >

> > > --- In Losmandy_users@yahoogroups.com, "frodil620206"

> > > frodil620206@> wrote:

> > > >

> > > > Hi, last weekend i made my first try to measure PE with

PEMPRO > but

> > > > don.t know how to interpret the results. Can somebody help

me > with

> > > > this?

> > > >

> > > > 5 worm cycles with PEC off

> > > >

farm3.static.flickr.com/2085/1517603481_a678c9e6ef_o.jpg > > > >

> > > > Grapf of PE frequency spectrum PEC off

> > > >

farm3.static.flickr.com/2025/1518454564_e2287991dc_o.jpg > > > >

> > > > 2 worm cycles with PEC on

> > > >

farm3.static.flickr.com/2065/1517603877_6dec23136b_o.jpg > > > >

> > > > Grapf of PE frequency spectrum PEC on

> > > >

farm3.static.flickr.com/2291/1517603931_272ef1ff39_o.jpg > > > >

> > > > Peak to peak before and after PEC

> > > >

farm3.static.flickr.com/2168/1518454768_4dd9c7eed2_o.jpg > > > >

> > > > What do you think about this?

> > > >

> > > > Thanks in advance and clear skies, Florencio

> > > >

> > >

> >

>



----------------------------

#34516 Oct 8, 2007

frodil620206 wrote:

> What about the 76 secs error? Can it be diagnose from this data?



Yes. On the PEMPro Analyze tab, click Create a PE Curve. On the Graph

Type drop-down, select Frequency Spectrum (secs). Look for a peak at the

1.3-minute time. Position the mouse pointer on the top of this spike,

and read the period and amplitude above the graph. When creating a PE

curve, you might want to un-check the 3.000 fundamental in the FFT

Wavefprm Analysis list, since the 76s error is at 3.15X (but

asynchronous), and you don't want it included in the PE calculation.





--



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com



----------------------------

#34517 Oct 8, 2007

Your two worm cycles with PEC on show quite a deal of drift.



Greg



----------------------------

#34527 Oct 8, 2007

Hi Greg, could it be because of bad polar alignment?



Regards, Florencio



----------------------------

#36180 Jan 31, 2008

Hi all,



This is perhaps out of topic but have to ask:

I'm designing a permanent observatory and if I want a long permanent

pier let say 210cm, approx what diameter is needed (and material

thickness)? Let say steel put into solid rock, maybe concrete filled.



Best



Lars



----------------------------

#36181 Jan 31, 2008

Hi Lars,



If I would built a pier like that I would not use a steel pipe all

that long.



I would make it of concrete and in conical shape and then the last

part maybe 60cm of steel pipe.



So you have rock as a base which I think is good.



I would start with 60cm round and then after 150cm finish it at about

40cm round and then the rest with a steel pipe of minimum 25cm better

30cm



best regards Rainer



>

> Hi all,

>

> This is perhaps out of topic but have to ask:

> I'm designing a permanent observatory and if I want a long

permanent > pier let say 210cm, approx what diameter is needed (and material

> thickness)? Let say steel put into solid rock, maybe concrete

filled. >

> Best

>

> Lars

>



----------------------------

#36182 Jan 31, 2008

This is totally on topic. And even if it were a bit off, the idea

here is not to be one of those groups where, if you dropped in a piece

of coal, it would come out a diamond a week later.



In answer to your question, one way to proceed is to call a vendor

like ATS and ask what they would recommend. By telling them you are

thinking of designing an observatory around their permanent pier you

can probably get the dimensions out of them.



My general thought, however, is that the pier should be over-built and

over specified with some kind of adapter in mind. The reason being

that you may not want to use the G11 forever. So if you designed to

accommodate a Parmount ME and had an adapter then down the road it

won't seem so nutty to upgrade to a Titan or an AP900, 1200, as you

see fit and as income allows.



Another way to approach the problem is that maybe you want "the

stability of a permanent pier but maybe sometime you'd like to take it

all out." In which case designing your observatory to accommodate a

portable pier (ATS again, or Particle Wave Technologies, PWT) would

work. Parallax has an interesting portable pier design that might

also serve in a permanent mounting situation.



There is another pier company that I see advertising in a small box

add (with picture) in the back of S&T that you might contact, but I

don't remember their name (someone here probably would).



It wouldn't be a bad idea if we had some CAD drawings of the

dimensions of a g8, g11, Titan, HGM 200, and anything else we can

think of in order to answer these kinds of questions with great

precision. Regrettably I'm not in a position to provide that kind of

resource, but with over three thousand members, we might find a

volunteer. If there are such drawings here already I've forgotten

about them, but you should also nose around our FILES and PHOTOs

sections, as well as LINKs. You might for example find some LINKS to

people who have built permanent piers.



Roth Ritter used to image with a G11/c11, I don't know what he's using

these days. (google him)



hope that helps

Greg N







--- In Losmandy_users@yahoogroups.com, "lgw09" lgw@...> wrote:

>

> Hi all,

>

> This is perhaps out of topic but have to ask:

> I'm designing a permanent observatory and if I want a long permanent

> pier let say 210cm, approx what diameter is needed (and material

> thickness)? Let say steel put into solid rock, maybe concrete filled.

>

> Best

>

> Lars

>







----------------------------

#36183 Jan 31, 2008

All:



Speaking of concrete piers or steel piers - I am a licensed

structural engineer versed in steel and concrete design. I can

produce detailed design drawings to suit your needs if anyone needs

help designing a custom pier...

Scott

--- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@...> wrote:

>

> Hi Lars,

>

> If I would built a pier like that I would not use a steel pipe all

> that long.

>

> I would make it of concrete and in conical shape and then the last

> part maybe 60cm of steel pipe.

>

> So you have rock as a base which I think is good.

>

> I would start with 60cm round and then after 150cm finish it at

about

> 40cm round and then the rest with a steel pipe of minimum 25cm

better

> 30cm

>

> best regards Rainer

>

>

> >

> > Hi all,

> >

> > This is perhaps out of topic but have to ask:

> > I'm designing a permanent observatory and if I want a long

> permanent

> > pier let say 210cm, approx what diameter is needed (and material

> > thickness)? Let say steel put into solid rock, maybe concrete

> filled.

> >

> > Best

> >

> > Lars

> >

>



----------------------------

#36184 Jan 31, 2008

Lars,



I built a steel pier 87" (220cm) out of 10" (25cm) diameter steel pipe with a wall thickness of 3/8"

(9.5mm). The base is 24" (60.9cm) by 1/2" (12.7mm) thick and the upper flange is 12" (30cm) by 3/4"

(19mm) thick. There are four gussets 1/4" (6.3mm) thick by 44" (110cm) welded to the steel pipe and

it was filled with sand. It is bolted to a concrete base that was built for another telescope. I had

to design around what was already installed in the observatory.



tech.groups.yahoo.com/group/dvaa/files/Equipment/New_Pier.jpg

----- Original Message -----

From: "lgw09" lgw@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, January 31, 2008 4:24 PM

Subject: [Losmandy_users] Permanent pier for G11, perhaps out of topic





> Hi all,

>

> This is perhaps out of topic but have to ask:

> I'm designing a permanent observatory and if I want a long permanent

> pier let say 210cm, approx what diameter is needed (and material

> thickness)? Let say steel put into solid rock, maybe concrete filled.

>

> Best

>

> Lars

>

>

>

>

>

>

> Yahoo! Groups Links

>

>

>

>



----------------------------

#36188 Feb 1 2:54 AM

Steel and concrete don't mix that great when filling the steel with

concrete.



Rainer's solution is better I believe... take a look at

clientes.netvisao.pt/jcanela/html/46.htm and check the pier...



It's a GM8... but it will be the same on a G11.



Hope it helped.



Regards,



Canela

cliente.netvisao.pt/jcanela/>



---------------



From: Losmandy_users@yahoogroups.com

[mailto:Losmandy_users@yahoogroups.com] On Behalf Of Rainer

Sent: quinta-feira, 31 de Janeiro de 2008 22:06

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Permanent pier for G11, perhaps out of

topic







Hi Lars,



If I would built a pier like that I would not use a steel pipe all

that long.



I would make it of concrete and in conical shape and then the last

part maybe 60cm of steel pipe.



So you have rock as a base which I think is good.



I would start with 60cm round and then after 150cm finish it at about

40cm round and then the rest with a steel pipe of minimum 25cm better

30cm



best regards Rainer

>

> Hi all,

>

> This is perhaps out of topic but have to ask:

> I'm designing a permanent observatory and if I want a long

permanent > pier let say 210cm, approx what diameter is needed (and material

> thickness)? Let say steel put into solid rock, maybe concrete

filled. >

> Best

>

> Lars

>













[Non-text portions of this message have been removed]



----------------------------

#36189 Feb 1 3:17 AM

Scott,



if that's the case then I think the group would be very gratefull if

you did so.



Thanks in advance



Jose Canela



---------------



From: Losmandy_users@yahoogroups.com

[mailto:Losmandy_users@yahoogroups.com] On Behalf Of Scott

Sent: quinta-feira, 31 de Janeiro de 2008 23:33

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Permanent pier for G11, perhaps out of

topic







All:



Speaking of concrete piers or steel piers - I am a licensed

structural engineer versed in steel and concrete design. I can

produce detailed design drawings to suit your needs if anyone needs

help designing a custom pier...

Scott



--- In Losmandy_users@yahoogroups.com

mailto:Losmandy_users%40yahoogroups.com> , "Rainer" rsbfoto@...>

wrote: >

> Hi Lars,

>

> If I would built a pier like that I would not use a steel pipe all

> that long.

>

> I would make it of concrete and in conical shape and then the last

> part maybe 60cm of steel pipe.

>

> So you have rock as a base which I think is good.

>

> I would start with 60cm round and then after 150cm finish it at

about > 40cm round and then the rest with a steel pipe of minimum 25cm

better > 30cm

>

> best regards Rainer

>

>

> >

> > Hi all,

> >

> > This is perhaps out of topic but have to ask:

> > I'm designing a permanent observatory and if I want a long

> permanent

> > pier let say 210cm, approx what diameter is needed (and material

> > thickness)? Let say steel put into solid rock, maybe concrete

> filled.

> >

> > Best

> >

> > Lars

> >

>













[Non-text portions of this message have been removed]







----------------------------

#36190 Feb 1 3:35 AM

Hi



Thanks for your answer, in fact I will start doing a 3D-model of the

G11 this weekend, perhaps next week a can supply some pdf-drawings.

I'm using PRO-engineer for the job and I will do the whole

observatory in this program. By the way is there any illustrated part

diagram for the G11 mount? I know briefly what's inside but have an

exploded view is better. The reason why a want a tall pier is that

the building area is restricted and having a dome built is even more

restricted by my wife. By using a tall pier you can sort of

walk "under" the telescope and having walk around space even if the

floor area is quit small. It will be a "garden house" that need to

look as it really fits in to the surroundings and looks "sweet"

(wife).



Best



Lars



--- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...>

wrote: >

> This is totally on topic. And even if it were a bit off, the idea

> here is not to be one of those groups where, if you dropped in a

piece > of coal, it would come out a diamond a week later.

>

> In answer to your question, one way to proceed is to call a vendor

> like ATS and ask what they would recommend. By telling them you are

> thinking of designing an observatory around their permanent pier you

> can probably get the dimensions out of them.

>

> My general thought, however, is that the pier should be over-built

and > over specified with some kind of adapter in mind. The reason being

> that you may not want to use the G11 forever. So if you designed to

> accommodate a Parmount ME and had an adapter then down the road it

> won't seem so nutty to upgrade to a Titan or an AP900, 1200, as you

> see fit and as income allows.

>

> Another way to approach the problem is that maybe you want "the

> stability of a permanent pier but maybe sometime you'd like to take

it > all out." In which case designing your observatory to accommodate a

> portable pier (ATS again, or Particle Wave Technologies, PWT) would

> work. Parallax has an interesting portable pier design that might

> also serve in a permanent mounting situation.

>

> There is another pier company that I see advertising in a small box

> add (with picture) in the back of S&T that you might contact, but I

> don't remember their name (someone here probably would).

>

> It wouldn't be a bad idea if we had some CAD drawings of the

> dimensions of a g8, g11, Titan, HGM 200, and anything else we can

> think of in order to answer these kinds of questions with great

> precision. Regrettably I'm not in a position to provide that kind

of > resource, but with over three thousand members, we might find a

> volunteer. If there are such drawings here already I've forgotten

> about them, but you should also nose around our FILES and PHOTOs

> sections, as well as LINKs. You might for example find some LINKS

to > people who have built permanent piers.

>

> Roth Ritter used to image with a G11/c11, I don't know what he's

using > these days. (google him)

>

> hope that helps

> Greg N

>

>

>

>

> --- In Losmandy_users@yahoogroups.com, "lgw09" lgw@> wrote:

> >

> > Hi all,

> >

> > This is perhaps out of topic but have to ask:

> > I'm designing a permanent observatory and if I want a long

permanent > > pier let say 210cm, approx what diameter is needed (and material

> > thickness)? Let say steel put into solid rock, maybe concrete

filled. > >

> > Best

> >

> > Lars

> >

>



----------------------------

#36193 Feb 1 5:58 AM

Lars,



One small point: don't make the same mistake that I did and have the

pier too wide too high up. Depending on the shape of your telescope and

imaging equipment it may hit the pier when near the zenith!



Regards

John Moore

Fleet, Hants, England

homepage.ntlworld.com/john.moore88/index.htm



----------------------------

#36194 Feb 1 6:15 AM

jcmoore_uk wrote: > One small point: don't make the same mistake that I did and have the

> pier too wide too high up. Depending on the shape of your telescope and

> imaging equipment it may hit the pier when near the zenith!





Yes! I made that mistake and won't repeat it. My next observatory will

have a 12" concrete pier topped with a 6" metal tube to support the G-11.



Mike

--



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com



----------------------------

#36195 Feb 1 8:17 AM

I also have a permanent pier. Mine was originally made for a Meade LX90 8".

I put the base adapter for the GM-8/GM-11 on it. It works fine, but it is

now slightly high.







So make sure it is not too high.







Regards







Jim Holland







From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

On Behalf Of Mike Dodd

Sent: Friday, February 01, 2008 9:16 AM

To: Losmandy_users@yahoogroups.com

Subject: Re: [Losmandy_users] Re: Permanent pier for G11, perhaps out of

topic







jcmoore_uk wrote: > One small point: don't make the same mistake that I did and have the

> pier too wide too high up. Depending on the shape of your telescope and

> imaging equipment it may hit the pier when near the zenith!



Yes! I made that mistake and won't repeat it. My next observatory will

have a 12" concrete pier topped with a 6" metal tube to support the G-11.



Mike

--



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com











[Non-text portions of this message have been removed]







----------------------------

#36196 Feb 1 8:47 AM

Lars,



I should mention that the pier I built is for a 8" F/12 refractor on a large GEM mount, that I also

built.



Don

----- Original Message -----

From: "lgw09" lgw@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, January 31, 2008 4:24 PM

Subject: [Losmandy_users] Permanent pier for G11, perhaps out of topic





> Hi all,

>

> This is perhaps out of topic but have to ask:

> I'm designing a permanent observatory and if I want a long permanent

> pier let say 210cm, approx what diameter is needed (and material

> thickness)? Let say steel put into solid rock, maybe concrete filled.

>

> Best

>

> Lars

>



----------------------------

#38028 Jun 27, 2008

Hello



I am wondering if anyone have got the new Ovision worm on a G11 running with

Pem Pro?

Also, is the Ovision supplied with the parameters that can be programmed

into Pem Pro?



Many Thanks

geo.yahoo.com/serv?s=97359714/grpId=2103530/grpspId=1705082806/msgId

=38027/stime=1214581732/nc1=3848607/nc2=4507179/nc3=5379226>



Adrien Richardson







[Non-text portions of this message have been removed]



----------------------------

#38030 Jun 27, 2008

--- In Losmandy_users@yahoogroups.com, "Adrien Richardson"

biplane@...> wrote: >

> Hello

>

> I am wondering if anyone have got the new Ovision worm on a G11

running with > Pem Pro?

> Also, is the Ovision supplied with the parameters that can be programmed

> into Pem Pro?

>

> Many Thanks

>

geo.yahoo.com/serv?s=97359714/grpId=2103530/grpspId=1705082806/msgId > =38027/stime=1214581732/nc1=3848607/nc2=4507179/nc3=5379226>

>

> Adrien Richardson

>

>

>

> [Non-text portions of this message have been removed]



I'm perhaps missing something but why should the parameters be changed

as the worm is compatible with the original gear? >



----------------------------

#38038 Jun 27, 2008

Hi Adrien,



You should not need to change any PEMPro parameters with the Ovision worm.



-Ray

> -----Original Message-----

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com] On Behalf Of Adrien Richardson

> Sent: Friday, June 27, 2008 9:13 AM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] Ovision + G11 + Pem Pro ?

>

> Hello

>

> I am wondering if anyone have got the new Ovision worm on a

> G11 running with

> Pem Pro?

> Also, is the Ovision supplied with the parameters that can be

> programmed

> into Pem Pro?

>

> Many Thanks

> geo.yahoo.com/serv?s=97359714/grpId=2103530/grpspId=17

05082806/msgId geo.yahoo.com/serv?s=97359714/grpId=>

2103530/grpspId=1705082806/msgId> > =38027/stime=1214581732/nc1=3848607/nc2=4507179/nc3=5379226>

>

> Adrien Richardson

>

>

> [Non-text portions of this message have been removed]

>

>

>

>

>



----------------------------

#38041 Jun 28, 2008

Ray and Claudio



Thanks for that information. Yes, in fact thinking about it, if it is a

direct replacement it should not need any parameter changes...

For once, in this awfully scientific hobby, there is an easy solution!



Thanks



Adrien



_____



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

On Behalf Of Ray Gralak

Sent: Saturday, June 28, 2008 6:08 AM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Ovision + G11 + Pem Pro ?







Hi Adrien,



You should not need to change any PEMPro parameters with the Ovision worm.



-Ray

> -----Original Message-----

> From: Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

yahoogroups.com > [mailto:Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

yahoogroups.com] On Behalf Of Adrien Richardson > Sent: Friday, June 27, 2008 9:13 AM

> To: Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

yahoogroups.com > Subject: [Losmandy_users] Ovision + G11 + Pem Pro ?

>

> Hello

>

> I am wondering if anyone have got the new Ovision worm on a

> G11 running with

> Pem Pro?

> Also, is the Ovision supplied with the parameters that can be

> programmed

> into Pem Pro?

>

> Many Thanks

> geo.yahoo

geo.yahoo.com/serv?s=97359714/grpId=2103530/grpspId=17>

com/serv?s=97359714/grpId=2103530/grpspId=17

05082806/msgId geo.yahoo

geo.yahoo.com/serv?s=97359714/grpId=> com/serv?s=97359714/grpId=>

2103530/grpspId=1705082806/msgId> > =38027/stime=1214581732/nc1=3848607/nc2=4507179/nc3=5379226>

>

> Adrien Richardson

>

>

> [Non-text portions of this message have been removed]

>

>

>

>

>













[Non-text portions of this message have been removed]







----------------------------

#49011 Jun 28, 2011

Can anybody help me with my latest problem please. When you check the PE on the G11, does it make any diffrence what f/l you use, if it does, which would be the best f/l to use. Thanks



----------------------------

#49013 Jun 28, 2011

It contains references to Web.Dove's stuff in Files. It has been moved to Files>Material for Scott to See>Technical Proposals.



Gale

--- In Losmandy_users@yahoogroups.com, "drgenovese92853" drgenovese92853@...> wrote:

>

> See message 31208. for details of Dove Web's mods. Charles

>



----------------------------

#49014 Jun 28, 2011

See Files>Materials for Scott to see>Technical Proposals for Web's documents.



Gale

--- In Losmandy_users@yahoogroups.com, "drgenovese92853" drgenovese92853@...> wrote:

>

> See message 31208. for details of Dove Web's mods. Charles

>



----------------------------

#50630 Feb 27 5:11 PM

I would love to hear some feedback on my PE analysis. Screen shots are in the folder "Wiley." Question is: Do I have problems with non-harmonic errors that require upgrade to a one-piece worm block. Or, does it look like I can guide out the PE?



Most of my images look OK, but they require considerable guiding corrections, which is OK so long as the PE can be guided out. Besides "inquiring minds want to know." :)



Parameters

8" F4 (800" FL)

PHD log, PECPrep

ST402

40 minutes of data



Thanks, Ed



----------------------------

#50633 Feb 28 7:46 AM

Analyzing your mount can always be a slippery slope! What may have worked fine will now haunt you as "Is it the PE?" :-)



Actually the frequency spectrum looks pretty good. You have a small bit of the 76 error (the peak just to the right of the 2). But it's considerably smaller than the peak marked by 1 which is the overall worm error (non-harmonic error? Not sure what this is called). It's probably small enough to be insignificant.



Anyways, I would program PEC and see how things work out. Keep in mind that some versions of Gemini will run fast when PEC is turned on...which could cause you more problems. PEMPro can correct this. I'm not sure about PEC Prep as I've never used it. My G11 was fast by around 2ish arcseconds/minute! But PEMPro fixed it nicely!



Jared

--- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@...> wrote:

>

> I would love to hear some feedback on my PE analysis. Screen shots are in the folder "Wiley." Question is: Do I have problems with non-harmonic errors that require upgrade to a one-piece worm block. Or, does it look like I can guide out the PE?

>

> Most of my images look OK, but they require considerable guiding corrections, which is OK so long as the PE can be guided out. Besides "inquiring minds want to know." :)

>

> Parameters

> 8" F4 (800" FL)

> PHD log, PECPrep

> ST402

> 40 minutes of data

>

> Thanks, Ed

>



----------------------------

#50639 Feb 28 4:04 PM

Many thanks for the feedback, Jared. I figured I avoided the dreaded 76 second problem and it is good to get some positive feedback. I have a "push-to," not Gemini, and normally guide, but I will try the PEC (which seems quite smooth in the analysis) and see how it works.



BTW, I think that the largest peak is the primary harmonic and thus I should be able to guide it out. Peak to peak seems about normal for the G11 breed without the newer one-piece worm block. I have heard that some G11s have lower PE,



Clear skies,

Ed

--- In Losmandy_users@yahoogroups.com, "rockjockjared" jwellman@...> wrote:

>

> Analyzing your mount can always be a slippery slope! What may have worked fine will now haunt you as "Is it the PE?" :-)

>

> Actually the frequency spectrum looks pretty good. You have a small bit of the 76 error (the peak just to the right of the 2). But it's considerably smaller than the peak marked by 1 which is the overall worm error (non-harmonic error? Not sure what this is called). It's probably small enough to be insignificant.

>

> Anyways, I would program PEC and see how things work out. Keep in mind that some versions of Gemini will run fast when PEC is turned on...which could cause you more problems. PEMPro can correct this. I'm not sure about PEC Prep as I've never used it. My G11 was fast by around 2ish arcseconds/minute! But PEMPro fixed it nicely!

>

> Jared

>

> --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> >

> > I would love to hear some feedback on my PE analysis. Screen shots are in the folder "Wiley." Question is: Do I have problems with non-harmonic errors that require upgrade to a one-piece worm block. Or, does it look like I can guide out the PE?

> >

> > Most of my images look OK, but they require considerable guiding corrections, which is OK so long as the PE can be guided out. Besides "inquiring minds want to know." :)

> >

> > Parameters

> > 8" F4 (800" FL)

> > PHD log, PECPrep

> > ST402

> > 40 minutes of data

> >

> > Thanks, Ed

> >

>



----------------------------

#51233 Jul 4, 2012

i just completed a PEC analysis of my new G11. it does not have the one piece worm block, but apparently all new G11s ship with the precision worms.



my results are very, very similar to yours. just about 20 arcsec peak-to-peak.



i'm curious about what the best solution is to mitigate this problem. so far i know about the following, but i don't know which is most appropriate to try first:



1) readjust the RA worm to improve the fit

2) polish the RA worm and gear

3) shim the worm block to ensure that the worm is being held perpendicular to the RA gear

4) get a one-piece worm block





5) upload a PEC curve to the gemini2 after analysis with PEMPro or PECPrep

6) let gemini2 learn the PEC while the OTA is being guided



7) don't bother with any of this and just let PhD guide out the PEC and any polar misalignment.



#3 might actually be a solution to the 76/79s error, but it looks like i don't have that problem based on the PECPrep analysis.



#6 seems straightforward, but i don't know how much filtering and analysis the G2 does. and i'm not sure if it can handle polar misalignment the way PEMPro and PECPrep can.



it seems like one should first try to clean up as much mechanical stuff as possible, and then use PEC to fix the residual periodic error. but maybe others here know - is it reasonable to correct a PE of this magnitude with PEC? in other words, should i just not bother with mechanical solutions?



from reading around it seems that 20 arcsec pk-pk is kind of on the high side of things for a new G11 without the one piece worm block, which is why i'm thinking mechanical solutions might be in order.



as a start, if the weather holds tonight, i'll probably try and let G2 learn a curve to see what happens.



thanks,



rob



--- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@...> wrote:

>

> Many thanks for the feedback, Jared. I figured I avoided the dreaded 76 second problem and it is good to get some positive feedback. I have a "push-to," not Gemini, and normally guide, but I will try the PEC (which seems quite smooth in the analysis) and see how it works.

>

> BTW, I think that the largest peak is the primary harmonic and thus I should be able to guide it out. Peak to peak seems about normal for the G11 breed without the newer one-piece worm block. I have heard that some G11s have lower PE,

>

> Clear skies,

> Ed

>

> --- In Losmandy_users@yahoogroups.com, "rockjockjared" jwellman@> wrote:

> >

> > Analyzing your mount can always be a slippery slope! What may have worked fine will now haunt you as "Is it the PE?" :-)

> >

> > Actually the frequency spectrum looks pretty good. You have a small bit of the 76 error (the peak just to the right of the 2). But it's considerably smaller than the peak marked by 1 which is the overall worm error (non-harmonic error? Not sure what this is called). It's probably small enough to be insignificant.

> >

> > Anyways, I would program PEC and see how things work out. Keep in mind that some versions of Gemini will run fast when PEC is turned on...which could cause you more problems. PEMPro can correct this. I'm not sure about PEC Prep as I've never used it. My G11 was fast by around 2ish arcseconds/minute! But PEMPro fixed it nicely!

> >

> > Jared

> >

> > --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> > >

> > > I would love to hear some feedback on my PE analysis. Screen shots are in the folder "Wiley." Question is: Do I have problems with non-harmonic errors that require upgrade to a one-piece worm block. Or, does it look like I can guide out the PE?

> > >

> > > Most of my images look OK, but they require considerable guiding corrections, which is OK so long as the PE can be guided out. Besides "inquiring minds want to know." :)

> > >

> > > Parameters

> > > 8" F4 (800" FL)

> > > PHD log, PECPrep

> > > ST402

> > > 40 minutes of data

> > >

> > > Thanks, Ed

> > >

> >

>







----------------------------

#51236 Jul 4, 2012

Hi Rob:



No expert here, so take it as you will. My experience is that with good polar alignment (drift alignment) a smooth periodic error is easily guided out. I have never used the PEC but I understand that guiding and PEC are somewhat incompatible as they can work against each other. If you do not have a good polar alignment even good guiding will result in image rotation. If the PE really bugs you I would suggest option #4. And, #3 does seem to be the solution for the "76 wobble" see:



www.wilmslowastro.com/tips/g11gemini.htm#bearing_block



I don't know about #s 5-6, can't help you there. But I do have a GeminiII retrofit on the way!



Ed

--- In Losmandy_users@yahoogroups.com, "pfile" yahoo@...> wrote:

>

>

>

>

>

>

>

>

>

> i just completed a PEC analysis of my new G11. it does not have the one piece worm block, but apparently all new G11s ship with the precision worms.

>

> my results are very, very similar to yours. just about 20 arcsec peak-to-peak.

>

> i'm curious about what the best solution is to mitigate this problem. so far i know about the following, but i don't know which is most appropriate to try first:

>

> 1) readjust the RA worm to improve the fit

> 2) polish the RA worm and gear

> 3) shim the worm block to ensure that the worm is being held perpendicular to the RA gear

> 4) get a one-piece worm block

>

>

> 5) upload a PEC curve to the gemini2 after analysis with PEMPro or PECPrep

> 6) let gemini2 learn the PEC while the OTA is being guided

>

> 7) don't bother with any of this and just let PhD guide out the PEC and any polar misalignment.

>

> #3 might actually be a solution to the 76/79s error, but it looks like i don't have that problem based on the PECPrep analysis.

>

> #6 seems straightforward, but i don't know how much filtering and analysis the G2 does. and i'm not sure if it can handle polar misalignment the way PEMPro and PECPrep can.

>

> it seems like one should first try to clean up as much mechanical stuff as possible, and then use PEC to fix the residual periodic error. but maybe others here know - is it reasonable to correct a PE of this magnitude with PEC? in other words, should i just not bother with mechanical solutions?

>

> from reading around it seems that 20 arcsec pk-pk is kind of on the high side of things for a new G11 without the one piece worm block, which is why i'm thinking mechanical solutions might be in order.

>

> as a start, if the weather holds tonight, i'll probably try and let G2 learn a curve to see what happens.

>

> thanks,

>

> rob

>

>

> --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> >

> > Many thanks for the feedback, Jared. I figured I avoided the dreaded 76 second problem and it is good to get some positive feedback. I have a "push-to," not Gemini, and normally guide, but I will try the PEC (which seems quite smooth in the analysis) and see how it works.

> >

> > BTW, I think that the largest peak is the primary harmonic and thus I should be able to guide it out. Peak to peak seems about normal for the G11 breed without the newer one-piece worm block. I have heard that some G11s have lower PE,

> >

> > Clear skies,

> > Ed

> >

> > --- In Losmandy_users@yahoogroups.com, "rockjockjared" jwellman@> wrote:

> > >

> > > Analyzing your mount can always be a slippery slope! What may have worked fine will now haunt you as "Is it the PE?" :-)

> > >

> > > Actually the frequency spectrum looks pretty good. You have a small bit of the 76 error (the peak just to the right of the 2). But it's considerably smaller than the peak marked by 1 which is the overall worm error (non-harmonic error? Not sure what this is called). It's probably small enough to be insignificant.

> > >

> > > Anyways, I would program PEC and see how things work out. Keep in mind that some versions of Gemini will run fast when PEC is turned on...which could cause you more problems. PEMPro can correct this. I'm not sure about PEC Prep as I've never used it. My G11 was fast by around 2ish arcseconds/minute! But PEMPro fixed it nicely!

> > >

> > > Jared

> > >

> > > --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> > > >

> > > > I would love to hear some feedback on my PE analysis. Screen shots are in the folder "Wiley." Question is: Do I have problems with non-harmonic errors that require upgrade to a one-piece worm block. Or, does it look like I can guide out the PE?

> > > >

> > > > Most of my images look OK, but they require considerable guiding corrections, which is OK so long as the PE can be guided out. Besides "inquiring minds want to know." :)

> > > >

> > > > Parameters

> > > > 8" F4 (800" FL)

> > > > PHD log, PECPrep

> > > > ST402

> > > > 40 minutes of data

> > > >

> > > > Thanks, Ed

> > > >

> > >

> >

>



----------------------------

#51240 Jul 5, 2012

Ed,



If it was me I would:



1. Just try guiding it out. The curve looks pretty smooth. A 20 arc second peak to peak smooth PE would represent an error rate of 10*2*pi/240 arcsec per second (of time) or roughly 1/4 arc sec per sec. If you use a 2 second guider exposure, then you'll have an uncorrected error of 1/2 arc second. Unless your focal length is real long, that should not be a problem. The atmosphere will probably cause more blur that that.



2. If just guiding alone doesn't work to your satisfaction, then try turning on PEC. If the PEC algorithm is implemented correctly in your mount guiding and PEC should work happily together. Short of having the software design in front of you there is no way to know without testing. I occasionally turn it on in my Digital Drive (not Gemini) mount but rarely need to use it. I would guess that PEC would reduce the size of the swing by about 50-60% in your case but in the spirit of KISS, I wouldn't use it unless I had to: Just one more variable to get hosed up.



If neither of those works then:



3. Try adjusting the worm blocks. Don't overdo the tightness of the worm-to-worm wheel fit. Don't overtorque the mounting bolts of the blocks either. Instead, try to get the two blocks parallel to each other. I was able to get mine (with the high precision worm and the stock two-piece worm mount) down to 10 arc-seconds peak to peak but it may have been dumb luck.



Your curve looks pretty smooth to the eyeball, so I don't think polishing the worm and worm wheel is called for at all.



Enjoy!



Mark Christensen

--- In Losmandy_users@yahoogroups.com, "pfile" yahoo@...> wrote:

>

>

>

>

>

>

>

>

>

> i just completed a PEC analysis of my new G11. it does not have the one piece worm block, but apparently all new G11s ship with the precision worms.

>

> my results are very, very similar to yours. just about 20 arcsec peak-to-peak.

>

> i'm curious about what the best solution is to mitigate this problem. so far i know about the following, but i don't know which is most appropriate to try first:

>

> 1) readjust the RA worm to improve the fit

> 2) polish the RA worm and gear

> 3) shim the worm block to ensure that the worm is being held perpendicular to the RA gear

> 4) get a one-piece worm block

>

>

> 5) upload a PEC curve to the gemini2 after analysis with PEMPro or PECPrep

> 6) let gemini2 learn the PEC while the OTA is being guided

>

> 7) don't bother with any of this and just let PhD guide out the PEC and any polar misalignment.

>

> #3 might actually be a solution to the 76/79s error, but it looks like i don't have that problem based on the PECPrep analysis.

>

> #6 seems straightforward, but i don't know how much filtering and analysis the G2 does. and i'm not sure if it can handle polar misalignment the way PEMPro and PECPrep can.

>

> it seems like one should first try to clean up as much mechanical stuff as possible, and then use PEC to fix the residual periodic error. but maybe others here know - is it reasonable to correct a PE of this magnitude with PEC? in other words, should i just not bother with mechanical solutions?

>

> from reading around it seems that 20 arcsec pk-pk is kind of on the high side of things for a new G11 without the one piece worm block, which is why i'm thinking mechanical solutions might be in order.

>

> as a start, if the weather holds tonight, i'll probably try and let G2 learn a curve to see what happens.

>

> thanks,

>

> rob

>

>

> --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> >

> > Many thanks for the feedback, Jared. I figured I avoided the dreaded 76 second problem and it is good to get some positive feedback. I have a "push-to," not Gemini, and normally guide, but I will try the PEC (which seems quite smooth in the analysis) and see how it works.

> >

> > BTW, I think that the largest peak is the primary harmonic and thus I should be able to guide it out. Peak to peak seems about normal for the G11 breed without the newer one-piece worm block. I have heard that some G11s have lower PE,

> >

> > Clear skies,

> > Ed

> >

> > --- In Losmandy_users@yahoogroups.com, "rockjockjared" jwellman@> wrote:

> > >

> > > Analyzing your mount can always be a slippery slope! What may have worked fine will now haunt you as "Is it the PE?" :-)

> > >

> > > Actually the frequency spectrum looks pretty good. You have a small bit of the 76 error (the peak just to the right of the 2). But it's considerably smaller than the peak marked by 1 which is the overall worm error (non-harmonic error? Not sure what this is called). It's probably small enough to be insignificant.

> > >

> > > Anyways, I would program PEC and see how things work out. Keep in mind that some versions of Gemini will run fast when PEC is turned on...which could cause you more problems. PEMPro can correct this. I'm not sure about PEC Prep as I've never used it. My G11 was fast by around 2ish arcseconds/minute! But PEMPro fixed it nicely!

> > >

> > > Jared

> > >

> > > --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> > > >

> > > > I would love to hear some feedback on my PE analysis. Screen shots are in the folder "Wiley." Question is: Do I have problems with non-harmonic errors that require upgrade to a one-piece worm block. Or, does it look like I can guide out the PE?

> > > >

> > > > Most of my images look OK, but they require considerable guiding corrections, which is OK so long as the PE can be guided out. Besides "inquiring minds want to know." :)

> > > >

> > > > Parameters

> > > > 8" F4 (800" FL)

> > > > PHD log, PECPrep

> > > > ST402

> > > > 40 minutes of data

> > > >

> > > > Thanks, Ed

> > > >

> > >

> >

>







----------------------------

#51242 Jul 5, 2012

thanks for the reply and sorry for the confusion. i think you are answering me, but i had replied to Ed's post since his original post was almost exactly the same as what i was about to post, PE-wise.



i only captured 3 cycles of the worm gear in my own analysis. i should probably do a longer capture and post that for people to look at.



i did a couple of test exposures (with PhD guiding the mount, 1s guide exposures) and at 10 minutes stars were mostly round at 1100mm focal length. the only problem is that soon i want to move to 2000mm so i'm thinking i have to really dial in the RA tracking. of course my guiding image scale is too large and perhaps if i just fixed that problem i'd be able to guide at 2000mm just fine with this PE.



i guess i have been thinking of getting the one piece worm block since that does seem appropriate for astrophotography. my only concern is that i'll screw up the installation and the end result will be worse :) i'll have to read up as much as i can about this before even thinking of attempting to adjust the worm.



thanks for the advice,



rob







--- In Losmandy_users@yahoogroups.com, "Mark C" mjcw500@...> wrote:

>

> Ed,

>

> If it was me I would:

>

> 1. Just try guiding it out. The curve looks pretty smooth. A 20 arc second peak to peak smooth PE would represent an error rate of 10*2*pi/240 arcsec per second (of time) or roughly 1/4 arc sec per sec. If you use a 2 second guider exposure, then you'll have an uncorrected error of 1/2 arc second. Unless your focal length is real long, that should not be a problem. The atmosphere will probably cause more blur that that.

>

> 2. If just guiding alone doesn't work to your satisfaction, then try turning on PEC. If the PEC algorithm is implemented correctly in your mount guiding and PEC should work happily together. Short of having the software design in front of you there is no way to know without testing. I occasionally turn it on in my Digital Drive (not Gemini) mount but rarely need to use it. I would guess that PEC would reduce the size of the swing by about 50-60% in your case but in the spirit of KISS, I wouldn't use it unless I had to: Just one more variable to get hosed up.

>

> If neither of those works then:

>

> 3. Try adjusting the worm blocks. Don't overdo the tightness of the worm-to-worm wheel fit. Don't overtorque the mounting bolts of the blocks either. Instead, try to get the two blocks parallel to each other. I was able to get mine (with the high precision worm and the stock two-piece worm mount) down to 10 arc-seconds peak to peak but it may have been dumb luck.

>

> Your curve looks pretty smooth to the eyeball, so I don't think polishing the worm and worm wheel is called for at all.

>

> Enjoy!

>

> Mark Christensen

>

> --- In Losmandy_users@yahoogroups.com, "pfile" yahoo@> wrote:

> >

> >

> >

> >

> >

> >

> >

> >

> >

> > i just completed a PEC analysis of my new G11. it does not have the one piece worm block, but apparently all new G11s ship with the precision worms.

> >

> > my results are very, very similar to yours. just about 20 arcsec peak-to-peak.

> >

> > i'm curious about what the best solution is to mitigate this problem. so far i know about the following, but i don't know which is most appropriate to try first:

> >

> > 1) readjust the RA worm to improve the fit

> > 2) polish the RA worm and gear

> > 3) shim the worm block to ensure that the worm is being held perpendicular to the RA gear

> > 4) get a one-piece worm block

> >

> >

> > 5) upload a PEC curve to the gemini2 after analysis with PEMPro or PECPrep

> > 6) let gemini2 learn the PEC while the OTA is being guided

> >

> > 7) don't bother with any of this and just let PhD guide out the PEC and any polar misalignment.

> >

> > #3 might actually be a solution to the 76/79s error, but it looks like i don't have that problem based on the PECPrep analysis.

> >

> > #6 seems straightforward, but i don't know how much filtering and analysis the G2 does. and i'm not sure if it can handle polar misalignment the way PEMPro and PECPrep can.

> >

> > it seems like one should first try to clean up as much mechanical stuff as possible, and then use PEC to fix the residual periodic error. but maybe others here know - is it reasonable to correct a PE of this magnitude with PEC? in other words, should i just not bother with mechanical solutions?

> >

> > from reading around it seems that 20 arcsec pk-pk is kind of on the high side of things for a new G11 without the one piece worm block, which is why i'm thinking mechanical solutions might be in order.

> >

> > as a start, if the weather holds tonight, i'll probably try and let G2 learn a curve to see what happens.

> >

> > thanks,

> >

> > rob

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> > >

> > > Many thanks for the feedback, Jared. I figured I avoided the dreaded 76 second problem and it is good to get some positive feedback. I have a "push-to," not Gemini, and normally guide, but I will try the PEC (which seems quite smooth in the analysis) and see how it works.

> > >

> > > BTW, I think that the largest peak is the primary harmonic and thus I should be able to guide it out. Peak to peak seems about normal for the G11 breed without the newer one-piece worm block. I have heard that some G11s have lower PE,

> > >

> > > Clear skies,

> > > Ed

> > >

> > > --- In Losmandy_users@yahoogroups.com, "rockjockjared" jwellman@> wrote:

> > > >

> > > > Analyzing your mount can always be a slippery slope! What may have worked fine will now haunt you as "Is it the PE?" :-)

> > > >

> > > > Actually the frequency spectrum looks pretty good. You have a small bit of the 76 error (the peak just to the right of the 2). But it's considerably smaller than the peak marked by 1 which is the overall worm error (non-harmonic error? Not sure what this is called). It's probably small enough to be insignificant.

> > > >

> > > > Anyways, I would program PEC and see how things work out. Keep in mind that some versions of Gemini will run fast when PEC is turned on...which could cause you more problems. PEMPro can correct this. I'm not sure about PEC Prep as I've never used it. My G11 was fast by around 2ish arcseconds/minute! But PEMPro fixed it nicely!

> > > >

> > > > Jared

> > > >

> > > > --- In Losmandy_users@yahoogroups.com, "Ed Wiley" edwiley@> wrote:

> > > > >

> > > > > I would love to hear some feedback on my PE analysis. Screen shots are in the folder "Wiley." Question is: Do I have problems with non-harmonic errors that require upgrade to a one-piece worm block. Or, does it look like I can guide out the PE?

> > > > >

> > > > > Most of my images look OK, but they require considerable guiding corrections, which is OK so long as the PE can be guided out. Besides "inquiring minds want to know." :)

> > > > >

> > > > > Parameters

> > > > > 8" F4 (800" FL)

> > > > > PHD log, PECPrep

> > > > > ST402

> > > > > 40 minutes of data

> > > > >

> > > > > Thanks, Ed

> > > > >

> > > >

> > >

> >

>







----------------------------

#52821 May 15, 2013

I have a 20-year-old G11. Several years ago I replaced its original RA worm, which had a PE of about 25", with a steel "precision worm". A few weeks ago I finally got around to measuring its error by making one of those misaligned tracking images. If my methodology is correct, the current error is about 8" peak-to-valley. I guess I won't bother with an Ovision worm or a One Piece Worm Block.





Joe Bergeron



Fellow, International Association of Astronomical Artists



www.joebergeron.com



----------------------------

#53970 Mar 16, 2014

I've been using the G11/Gemini 2 since 2011. ��I've never had problems with this mount and have been happy with it's performance and never found a need to record PE until recently, when I just became curious. ��This was my first time using PEMPro and I followed the directions as outlined.The first curve��(Before PEC)��was taken with 7 cycles and showed a peak to peak of 4.64 arc-sec and the second curve��(After PEC)��was taken with 3 cycles and corrected to 2.78 arc-sec.Focal length of scope 1625mmImaging camera QSI 683Mount: Losmandy G11 with Gemini 2 (purchased in 2011)If I did this correctly (and I understand what was collected) I am quite happy with these results.



----------------------------

#56346 Oct 26, 2015

I just wanted to say a public thanks to Michael Herman for his article in the files section "Improving the Losmandy G11 OPW.pdf". ��The article outlines the addition of a small disk spring washer and improved worm bearings to improve the raw PE of the mount. ��Since I needed to disassemble and re-grease the mount anyway, I decided to give the improvement a try. ��I'm glad I did! ��The raw peak PE went from +/- 8 arcs to +/- 5 arcs, and the RMS PE went from��3.97 arcs to 1.88 arcs. ��Thanks Michael!

joel��



----------------------------

#56347 Oct 26, 2015

Many thanks for that comment, Joel.David Partridge also got notable PE improvement by adding an inexpensive. Belleville washer to his G11.. So far...and doing one has not had a negative effect on the few systems that added it..Glad to help the Losmandy group in any way, as I was helped greatly by earlier investigations and reports by other owners.. I have cited some of those in that PDF report too..Stay well, and have fun everyone...and keep those beautiful images coming....Michael



On Oct 26, 2015 6:31 AM, "buckeyestargazer@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:

.I just wanted to say a public thanks to Michael Herman for his article in the files section "Improving the Losmandy G11 OPW.pdf".. The article outlines the addition of a small disk spring washer and improved worm bearings to improve the raw PE of the mount.. Since I needed to disassemble and re-grease the mount anyway, I decided to give the improvement a try.. I'm glad I did!. The raw peak PE went from +/- 8 arcs to +/- 5 arcs, and the RMS PE went from.3.97 arcs to 1.88 arcs.. Thanks Michael!

joel.



----------------------------

#56348 Oct 26, 2015

To anyone interested, the link to Michael writeup are here.

also I have posted that page and his individual pdf files (with hispermission of course) at

gemini-2.comunder Manuals/tips/Misc -->Tips from other sites -->MichaelHerman G11 tips.

Use the blue drop down menus.



Thanks Michael again for all of your advise.

Tom Hilton



On 10/26/2015 9:33 AM, Michael Hermanmherman346@... [Losmandy_users] wrote:

.Many thanks for that comment, Joel.David Partridge also got notable PE improvementby adding an inexpensive. Belleville washer to his G11..So far...and doing one has not had a negative effect onthe few systems that added it..Glad to help the Losmandy group in any way, asI was helped greatly by earlier investigations and reportsby other owners.. I have cited some of those in that PDFreport too..Stay well, and have fun everyone...and keepthose beautiful images coming....Michael







On Oct 26, 2015 6:31 AM, "buckeyestargazer@...[Losmandy_users]" Losmandy_users@yahoogroups.com>wrote:

.I just wanted to say a public thanks toMichael Herman for his article in the filessection "Improving the Losmandy G11OPW.pdf".. The article outlines the additionof a small disk spring washer and improvedworm bearings to improve the raw PE of themount.. Since I needed to disassemble andre-grease the mount anyway, I decided togive the improvement a try.. I'm glad Idid!. The raw peak PE went from +/- 8 arcsto +/- 5 arcs, and the RMS PE went from.3.97arcs to 1.88 arcs.. Thanks Michael!



joel.



----------------------------

#56349 Oct 26, 2015

Anyone happen to know whether this washer will also fit in the original

worm/block design (non-opw)_configuration? Has anyone tried it with the

old system?



Tom





On 10/26/2015 1:24 PM, 'tom@...' tom@...

[Losmandy_users] wrote: >

>

> To anyone interested, the link to Michael writeup are here

> www.michaelherman.net/#%21losmandy-g11-mount>.

> also I have posted that page and his individual pdf files (with his

> permission of course) at

> gemini-2.com under Manuals/tips/Misc -->Tips from other sites

> -->Michael Herman G11 tips.

> Use the blue drop down menus.

>

> Thanks Michael again for all of your advise.

> Tom Hilton

>

>

> On 10/26/2015 9:33 AM, Michael Herman mherman346@...

> [Losmandy_users] wrote:

>>

>> Many thanks for that comment, Joel.

>>

>> David Partridge also got notable PE improvement by adding an

>> inexpensive Belleville washer to his G11. So far...and doing one has

>> not had a negative effect on the few systems that added it.

>>

>> Glad to help the Losmandy group in any way, as I was helped greatly by

>> earlier investigations and reports by other owners. I have cited some

>> of those in that PDF report too.

>>

>> Stay well, and have fun everyone...and keep those beautiful images

>> coming....

>>

>> Michael

>>

>>

>>

>> On Oct 26, 2015 6:31 AM,

>> "mailto:buckeyestargazer@...>buckeyestargazer@...

>> [Losmandy_users]" Losmandy_users@yahoogroups.com

>> mailto:Losmandy_users@yahoogroups.com>> wrote:

>>

>> I just wanted to say a public thanks to Michael Herman for his

>> article in the files section "Improving the Losmandy G11

>> OPW.pdf". The article outlines the addition of a small disk

>> spring washer and improved worm bearings to improve the raw PE of

>> the mount. Since I needed to disassemble and re-grease the mount

>> anyway, I decided to give the improvement a try. I'm glad I did!

>> The raw peak PE went from +/- 8 arcs to +/- 5 arcs, and the RMS PE

>> went from 3.97 arcs to 1.88 arcs. Thanks Michael!

>>

>>

>> joel

>>

>

>

>

>



--

Tom







----------------------------

#56350 Oct 26, 2015

I'm 98% certain that I read an old post on here where David Patridge put one of these washers on the DEC worm gear with the old 2 block configuration. .joel



----------------------------

#56352 Oct 26, 2015

Thanks Joel. I just ordered some to try on my mount. Inexpensive enough

to give it a try.



Tom



On 10/26/2015 3:52 PM, Joel Short buckeyestargazer@...

[Losmandy_users] wrote: >

>

> I'm 98% certain that I read an old post on here where David Patridge put

> one of these washers on the DEC worm gear with the old 2 block

> configuration.

> joel

>

>

>

>

>



--

Tom



----------------------------

#56353 Oct 26, 2015

Yes... it will.. In fact, David Partridge put the same Belleville washer into his original 2 part G11 worm blocks and he also saw big PE improvements... You might contact him for details or suggestions if you are going that route..The worm dimensions were not from the 2 part to the newer OPW worm block.. ..only the worm material changed from stainless steel to brass...Note that the super high end Ovision worm assembly from France does have a different worm design, but it also has a Belleville washer at the end away from the motor, to preload the worm axis..Best regards,

Michael

.Anyone happen to know whether this washer will also fit in the original

worm/block design (non-opw)_configuration? Has anyone tried it with the

old system?



Tom



On 10/26/2015 1:24 PM, 'tom@...' tom@...

[Losmandy_users] wrote:

>

>

> To anyone interested, the link to Michael writeup are here

> www.michaelherman.net/#%21losmandy-g11-mount>.

> also I have posted that page and his individual pdf files (with his

> permission of course) at

> gemini-2.com under Manuals/tips/Misc -->Tips from other sites

> -->Michael Herman G11 tips.

> Use the blue drop down menus.

>

> Thanks Michael again for all of your advise.

> Tom Hilton

>

>

> On 10/26/2015 9:33 AM, Michael Herman mherman346@...

> [Losmandy_users] wrote:

>>

>> Many thanks for that comment, Joel.

>>

>> David Partridge also got notable PE improvement by adding an

>> inexpensive Belleville washer to his G11. So far...and doing one has

>> not had a negative effect on the few systems that added it.

>>

>> Glad to help the Losmandy group in any way, as I was helped greatly by

>> earlier investigations and reports by other owners. I have cited some

>> of those in that PDF report too.

>>

>> Stay well, and have fun everyone...and keep those beautiful images

>> coming....

>>

>> Michael

>>

>>

>>

>> On Oct 26, 2015 6:31 AM,

>> "mailto:buckeyestargazer@...>buckeyestargazer@...

>> [Losmandy_users]" Losmandy_users@yahoogroups.com

>> mailto:Losmandy_users@yahoogroups.com>> wrote:

>>

>> I just wanted to say a public thanks to Michael Herman for his

>> article in the files section "Improving the Losmandy G11

>> OPW.pdf". The article outlines the addition of a small disk

>> spring washer and improved worm bearings to improve the raw PE of

>> the mount. Since I needed to disassemble and re-grease the mount

>> anyway, I decided to give the improvement a try. I'm glad I did!

>> The raw peak PE went from +/- 8 arcs to +/- 5 arcs, and the RMS PE

>> went from 3.97 arcs to 1.88 arcs. Thanks Michael!

>>

>>

>> joel

>>

>

>

>

>



--

Tom



----------------------------

#56354 Oct 26, 2015

...that is...2nd paragraph should say:."...we're not changed from the 2 part..."On Oct 26, 2015 5:15 PM, "Michael Herman" mherman346@...> wrote:Yes... it will.. In fact, David Partridge put the same Belleville washer into his original 2 part G11 worm blocks and he also saw big PE improvements... You might contact him for details or suggestions if you are going that route..The worm dimensions were not from the 2 part to the newer OPW worm block.. ..only the worm material changed from stainless steel to brass...Note that the super high end Ovision worm assembly from France does have a different worm design, but it also has a Belleville washer at the end away from the motor, to preload the worm axis..Best regards,

Michael

.Anyone happen to know whether this washer will also fit in the original

worm/block design (non-opw)_configuration? Has anyone tried it with the

old system?



Tom



On 10/26/2015 1:24 PM, 'tom@...' tom@...

[Losmandy_users] wrote:

>

>

> To anyone interested, the link to Michael writeup are here

> www.michaelherman.net/#%21losmandy-g11-mount>.

> also I have posted that page and his individual pdf files (with his

> permission of course) at

> gemini-2.com under Manuals/tips/Misc -->Tips from other sites

> -->Michael Herman G11 tips.

> Use the blue drop down menus.

>

> Thanks Michael again for all of your advise.

> Tom Hilton

>

>

> On 10/26/2015 9:33 AM, Michael Herman mherman346@...

> [Losmandy_users] wrote:

>>

>> Many thanks for that comment, Joel.

>>

>> David Partridge also got notable PE improvement by adding an

>> inexpensive Belleville washer to his G11. So far...and doing one has

>> not had a negative effect on the few systems that added it.

>>

>> Glad to help the Losmandy group in any way, as I was helped greatly by

>> earlier investigations and reports by other owners. I have cited some

>> of those in that PDF report too.

>>

>> Stay well, and have fun everyone...and keep those beautiful images

>> coming....

>>

>> Michael

>>

>>

>>

>> On Oct 26, 2015 6:31 AM,

>> "mailto:buckeyestargazer@...>buckeyestargazer@...

>> [Losmandy_users]" Losmandy_users@yahoogroups.com

>> mailto:Losmandy_users@yahoogroups.com>> wrote:

>>

>> I just wanted to say a public thanks to Michael Herman for his

>> article in the files section "Improving the Losmandy G11

>> OPW.pdf". The article outlines the addition of a small disk

>> spring washer and improved worm bearings to improve the raw PE of

>> the mount. Since I needed to disassemble and re-grease the mount

>> anyway, I decided to give the improvement a try. I'm glad I did!

>> The raw peak PE went from +/- 8 arcs to +/- 5 arcs, and the RMS PE

>> went from 3.97 arcs to 1.88 arcs. Thanks Michael!

>>

>>

>> joel

>>

>

>

>

>



--

Tom







----------------------------

#56356 Oct 27, 2015

Hi all,I already read the article, but alas it is impossible to obtain the washer in the Netherlands.The company says they cannot send to Europe ;-)Has anybody an idea where to find these washers in Europe/Netherlands?

Regards Arnold��



----------------------------

#56357 Oct 27, 2015

I.m not convinced that the Belleville washer helped much in the original two part worm (at least with the ABEC-5 bearings I used) as they were a pretty tight fit in the bearing blocks, and I don.t think the washer could actually move the bearing at all. ��If you still want one I can try to find the envelope that has one in it that Michael H. sent me that I didn.t use (no promises). ��PS anyone got a spare servo motor?. The one I rebuilt is giving DEC Lag messages and I don.t have enough spare $$$ to buy one of the new high torque motors ATM. ��

Regards,David Partridge From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com] Sent: 27 October 2015 10:32To: Losmandy_users@yahoogroups.comSubject: [Losmandy_users] Re: Thanks to Michael Herman for tips to improve G11 PE



----------------------------

#56358 Oct 27, 2015

Hi David,I would love to have it if you can find it, I do have the OPW btw...Or if someone in the States can send me one.��I can pay for it with PayPal!

Regards Arnold



----------------------------

#56359 Oct 27, 2015

Thanks for that information Michael. I will give it a go probably on

both axes. My PE is easily adjusted out with my ST-4 with the present

worms but I find it relatively easy to readjust the worm-gear mesh with

the two block arrangement so I can pop the washers in to see if I get

any improvement.



Tom



On 10/26/2015 8:17 PM, Michael Herman mherman346@...

[Losmandy_users] wrote: >

>

> ...that is...2nd paragraph should say:

>

> ."...we're not changed from the 2 part..."

>

> On Oct 26, 2015 5:15 PM, "Michael Herman" mherman346@...

> mailto:mherman346@...>> wrote:

>

> Yes... it will. In fact, David Partridge put the same Belleville

> washer into his original 2 part G11 worm blocks and he also saw big

> PE improvements. You might contact him for details or suggestions

> if you are going that route.

>

> The worm dimensions were not from the 2 part to the newer OPW worm

> block. ..only the worm material changed from stainless steel to brass.

>

> Note that the super high end Ovision worm assembly from France does

> have a different worm design, but it also has a Belleville washer at

> the end away from the motor, to preload the worm axis.

>

> Best regards,

> Michael

>

> __

>

> Anyone happen to know whether this washer will also fit in the original

> worm/block design (non-opw)_configuration? Has anyone tried it with the

> old system?

>

> Tom

>

> On 10/26/2015 1:24 PM, 'tom@... mailto:tom@...>'

> tom@... mailto:tom@...>

> [Losmandy_users] wrote:

> >

> >

> > To anyone interested, the link to Michael writeup are here

> > www.michaelherman.net/#%21losmandy-g11-mount>.

> > also I have posted that page and his individual pdf files (with his

> > permission of course) at

> > gemini-2.com under Manuals/tips/Misc -->Tips from other sites

> > -->Michael Herman G11 tips.

> > Use the blue drop down menus.

> >

> > Thanks Michael again for all of your advise.

> > Tom Hilton

> >

> >

> > On 10/26/2015 9:33 AM, Michael Herman mherman346@...

> mailto:mherman346@...>

> > [Losmandy_users] wrote:

> >>

> >> Many thanks for that comment, Joel.

> >>

> >> David Partridge also got notable PE improvement by adding an

> >> inexpensive Belleville washer to his G11. So far...and doing one has

> >> not had a negative effect on the few systems that added it.

> >>

> >> Glad to help the Losmandy group in any way, as I was helped

> greatly by

> >> earlier investigations and reports by other owners. I have cited

> some

> >> of those in that PDF report too.

> >>

> >> Stay well, and have fun everyone...and keep those beautiful images

> >> coming....

> >>

> >> Michael

> >>

> >>

> >>

> >> On Oct 26, 2015 6:31 AM,

> >> "mailto:buckeyestargazer@...

> mailto:buckeyestargazer@...>>buckeyestargazer@...

> mailto:buckeyestargazer@...>

> >> [Losmandy_users]" Losmandy_users@yahoogroups.com

> mailto:Losmandy_users@yahoogroups.com>

> >> mailto:Losmandy_users@yahoogroups.com

> mailto:Losmandy_users@yahoogroups.com>>> wrote:

> >>

> >> I just wanted to say a public thanks to Michael Herman for his

> >> article in the files section "Improving the Losmandy G11

> >> OPW.pdf". The article outlines the addition of a small disk

> >> spring washer and improved worm bearings to improve the raw PE of

> >> the mount. Since I needed to disassemble and re-grease the mount

> >> anyway, I decided to give the improvement a try. I'm glad I did!

> >> The raw peak PE went from +/- 8 arcs to +/- 5 arcs, and the RMS PE

> >> went from 3.97 arcs to 1.88 arcs. Thanks Michael!

> >>

> >>

> >> joel

> >>

> >

> >

> >

> >

>

> --

> Tom

>

>

>

>



--

Tom







----------------------------

#56360 Oct 27, 2015

Arnold and David,Arnold - I had to buy 10 washers in a pack so I've got several to spare and I can send you a couple.��David - If you want to try and rebuild the motor again I have a new spare motor (just the motor, not the encoder or housing). ��Or, I have been considering upgrading my DEC motor to the HT motor. ��I would need to find a HT motor first before letting the old one go. ��

Can we send private messages on here? ��I couldn't find an option to do so.

Also, can the HT motor just be swapped out with the original servo motor?

Regarding using the Bellville washer on the old two block worm bearing, I was going to try that myself since I've got plenty of washers. ��I have the old two block housing on the DEC axis (OPW on the RA). ��But I couldn't get the bearing out of the block housing. ��Does anyone have tips for removing the bearing? ��I tried Michael's method in the PDF document but I still couldn't get enough pull to remove it. ��joel



----------------------------

#56362 Oct 27, 2015

Hi Arnold...

Mannfred Guttenbrunner in Austria had the same problem... could not find a European supplier for the inexpensive washers.. He said he did find bearings though... . So I shipped him a few washers...

I only have 2 of the curved Belleville washers left... and you only need 1 per axis... these give 7 pounds force per washer once compressed. . . . I will try to order more washers in case other folks want to try this out. .I also have about 20 of a thinner "wavy" washer that also should work...(McMaster Carrr #9714K26 stock number) with lighter force.. I bought them but used and tested only the standard Belleville R4 sized washers. .

So if you send me your address, I'll mail you out 2 of the Belleville washers (they fit in a normal letter envelope).You can just PayPal me the cost of the washers and shipping envelope... I'd guess under $5 for an international letter.

The package of 10 washers is only $2.76, but the shipment has a minimum cost of about ~$8.00 since the McMaster Carr company only ships out package by UPS ... but I will call them to see if I can get that into just a US mail envelope for much lower cost.

More importantly, let me know if you also want me to get ABEC-7 bearings for you.. I think they are still available on eBay from Boca Bearings, for about $13 each.. You ideally need 3 of them for the OPW and 2 of them for the original separated bearing blocks.. The ABEC-7 bearings from Boca Bearings do not have any side to side wobble of the inner rotating part (that is, they are fitted.tighter), whereas there is noticeable wobble on the original G11 bearings. . .If you want those also, I will put together a kit for you... and let you know the price of that. .

All the best,Michael



----------------------------

#56363 Oct 27, 2015

Hi David!!!

You did get a much lower PE after your "repair job" of using the Belleville washer and the ABEC-5 bearings you used... at least that is what I recall...

Can you repeat for us what your initial and final results were?

Many thanks!!!!

Michael



----------------------------

#56364 Oct 27, 2015

I agree that I got a lower PE down from about 15. to 4.5. but believe that >>90% of that was due to the change over from worn out original bearings to new ABEC5 bearings.







I also think that for the cost of the Belleville washers (if you can find them in your country), that it.s a .no brainer. to insert one at the end away from the coupler as they can.t possibly do any harm and *may* help.











Regards,

David Partridge



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 27 October 2015 17:13

To: Losmandy_users@yahoogroups.com

Subject: Re: [Losmandy_users] Re: Thanks to Michael Herman for tips to improve G11 PE

















Hi David!!!







You did get a much lower PE after your "repair job" of using the Belleville washer and the ABEC-5 bearings you used... at least that is what I recall...







Can you repeat for us what your initial and final results were?







Many thanks!!!!







Michael









On Tue, Oct 27, 2015 at 3:49 AM, 'David C. Partridge' david.partridge@... [Losmandy_users] Losmandy_users@yahoogroups.com> wrote:







I.m not convinced that the Belleville washer helped much in the original two part worm (at least with the ABEC-5 bearings I used) as they were a pretty tight fit in the bearing blocks, and I don.t think the washer could actually move the bearing at all.







If you still want one I can try to find the envelope that has one in it that Michael H. sent me that I didn.t use (no promises).







PS anyone got a spare servo motor? The one I rebuilt is giving DEC Lag messages and I don.t have enough spare $$$ to buy one of the new high torque motors ATM.







Regards,

David Partridge



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 27 October 2015 10:32

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Thanks to Michael Herman for tips to improve G11 PE











Hi all,



I already read the article, but alas it is impossible to obtain the washer in the Netherlands.















--



Michael Herman

mobile: 408 421-1239

email: mherman346@...





















[Non-text portions of this message have been removed]







----------------------------

#56365 Oct 27, 2015

Hello Michael,

I really like the G11 and want to make it perform as good as possible, so if you can put together a kit including the bearings I would be very thankful!!

Regards Arnold



----------------------------

#56372 Oct 27, 2015

Arnold and other friends out east, ��Try: ��stores.ebay.com/DJ-Machinery?_trksid=p2047675.l2563 ��Their Ebay store offers shipping (International First Class) to the Netherlands and most of Europa. ��The firm is in Grand Rapids, MI, so if they won���t ship to the old country, nobody will ;-)It���s an inside joke ��� GR is right next to Zeeland and Holland, MI, which are well named!

McMaster-Carr must have gotten burned by the State Department export regulations at some point because they just won���t ship internationally, even to Canada. A pity. ��Mark Christensen



----------------------------

#56373 Oct 27, 2015

Ok.. Let me chase this down.Please tell me: do you have.. an original style (2 separate worm blocks takes 2 bearings),or a.. new style "One Piece Worm" called "OPW" type (takes 3 bearings) of RA system?.Do you want a DEC kit also. .. (and what type of worm blocks does that have)?I'll try to form a puller tool for you to pull out the existing back bearing too..And send me your address!All the best,

Michael

On Oct 27, 2015 11:38 AM, "ajtdebruin@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:

.Hello Michael,

I really like the G11 and want to make it perform as good as possible, so if you can put together a kit including the bearings I would be very thankful!!

Regards Arnold



----------------------------

#56375 Oct 27, 2015

David

Thanks for all the comments. I can't seem to send out PMs and this is the only way i could send you a message. Do you have any RA extenders left in your possession? i would really like to not hit my motor with the saddle again.��

Thanks

Hamzahamzakt@...480.352.0661



----------------------------

#56380 Oct 29, 2015

Hi Mark,

Just followed your link in ebay, but as I am "metric", even after reading the pdf from Michael I have no clue which washers I should order......;-(Michael's pdf mentions part# 94065K32, but what size is that???

Regards Arnold



----------------------------

#56381 Oct 29, 2015

Thanks for the suggestions. ��My G-11 was working as well as it ever had since I bought it new in 2008 (with the brass worm), PE wasn't too bad and it was easily handled either by my AO-8 or the SSAG guider. ��Then I started getting first a drift I couldn't account for (replaced the HC cable and RA cable, seemed to help) but I still have a somewhat jerky motion (a few arcseconds according to PhD) I could probable attribute to seeing - maybe. ��So before I take down a minimally working system, I ordered replacement worm blocks, the suggested bearings from a previous post, the washer and a new worm, just in case my old brass worm isn't as good as I thought it was. ��Then if I break something I can at least go back to what I started with! �� Worth a shot before jumping into the Ovision.



John



----------------------------

#56382 Oct 29, 2015

John,

When was the last time you cleaned and re-greased the mount? The

jerky-ness you describe could easily have been caused by grit in the

system.



I think you will see marked improvement just by cleaning and using the

new bearings and washer. I'm not sure the new worm was necessary,

especially if guiding was ok before. Good luck!

joel



----------------------------

#56384 Oct 30, 2015

Arnold, ��Well, since it is a McMaster-Carr part number (right?) if you go to their website and enter that number (sans space and # sign) into their search box up will pop the item description��� ��www.mcmaster.com/#catalog/121/1273/=zlbevi ��You could have also asked Mr. Google, using ���Washer 94065K32��� as your search phrase. They are used, it seems, in a variety of industries.The ones sold by the firm on Ebay, by the way, are made in Deutschland. ��Mark C.



----------------------------

#56385 Oct 30, 2015

Hi gang,

Just to be clear: .here is the description from the McMaster-Carr website: (.www.mcmaster.com )

Belleville Disc Spring for Ball Bearings, Bearing #R4, .406" ID, .618" OD, .0216" High



With 25.4 mm per inch, this corresponds to metric sizes:

10.3124 mm ID, . 15.6972 mm OD, . 0.54864 mm High

When compressed fully, this particular washer gives 7 pounds force (~ 31.1 Newtons)



Sold in packs of 10 for $2.76, almost weightless, but the minimum shipping rate (UPS or FedX) is usually the price killer...at least for me...

I just ordered 20 of these washers... so if anyone is interested in just getting a few of them, please contact me directly...at.mherman346@...or phone me at (USA:) .408 421-1239I'm in Sunnyvale, California... so timezone GMT -8 (-7 due to Daylight savings time... til Nov 1st Sunday..... isn't life complicated?!)

Also, if you are interested in getting the ABEC-7 bearings (1/4 " ID, 5/8" OD, 10/51 " thick), you can order them directly (eBay item, $12.95 each, $2 shipping in USA) from Boca Bearings as:www.ebay.com/itm/350886411467?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT



(I am surprised to still find that link works...since a look at the Boca Bearings website search does not show any matches to R4 ABEC 7 ... so much for computer searches...)



Or again, if you are international and want to save some shipping costs, let me know and I can put a kit together for you economically.. But you must let me know:1.. Your mailing address2.. How many bearings you want (it takes 2 per axis if you have the original 2 separate bearing blocks, or 3 if you have an OPW).3. How many Belleville washers you want.

You can then just PayPal me for the kit... I'll email you the cost with the shipping...

All the best,Michael







----------------------------

#56386 Oct 31, 2015

Hi Mark,��

I did think of that but could not figure out how 0.618" relates to 15/32 or whatever....Michael in the mean time has solved it for me :-)

Regards Arnold



----------------------------

#56387 Oct 31, 2015

Hi Tom,Sorry that I missed your note on this issue of the hard to remove rear bearing...that will probably come up replacing bearings.The removal of the "frozen in". rear bearing ... should not need drilling of the rear bearing block to remove it..When I also could not get my rear worm bearing out of its block, I fashioned a simple puller out of some steel wire...wrapped around a bolt to hole the puller jaws...You can find that hand made puller, and how to use it, described in the pages of my PDF document.... it describes the type of wire common in local hardware stores...and a common small bolt and nut...All the best,

MichaelOn Oct 27, 2015 6:20 AM, "tom loeblt@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:

.In one tough case I drilled a hole slightly larger in diameter than the

inner bearing race on the rear of the block and tapped the bearing out

with a drill bit. Odds are, if you do this, you will want to replace the

bearing in case it gets damaged in the process.



Tom



On 10/27/2015 9:04 AM, buckeyestargazer@... [Losmandy_users] wrote:

>

>

> Arnold and David,

> Arnold - I had to buy 10 washers in a pack so I've got several to spare

> and I can send you a couple.

> David - If you want to try and rebuild the motor again I have a new

> spare motor (just the motor, not the encoder or housing). Or, I have

> been considering upgrading my DEC motor to the HT motor. I would need

> to find a HT motor first before letting the old one go.

>

> Can we send private messages on here? I couldn't find an option to do so.

>

> Also, can the HT motor just be swapped out with the original servo motor?

>

> Regarding using the Bellville washer on the old two block worm bearing,

> I was going to try that myself since I've got plenty of washers. I have

> the old two block housing on the DEC axis (OPW on the RA). But I

> couldn't get the bearing out of the block housing. Does anyone have

> tips for removing the bearing? I tried Michael's method in the PDF

> document but I still couldn't get enough pull to remove it.

> joel

>

>

>



--

Tom



----------------------------

#56388 Oct 31, 2015

I recently saw your document Michael. I have an extra worm block set and

I just received some of the washers. I will try your puller trick on the

bearings of blocks I had not drilled.



Tom



On 10/31/2015 12:09 PM, Michael Herman mherman346@...

[Losmandy_users] wrote: >

>

> Hi Tom,

>

> Sorry that I missed your note on this issue of the hard to remove rear

> bearing...that will probably come up replacing bearings.

>

> The removal of the "frozen in" rear bearing ... should not need

> drilling of the rear bearing block to remove it.

>

> When I also could not get my rear worm bearing out of its block, I

> fashioned a simple puller out of some steel wire...wrapped around a bolt

> to hole the puller jaws.

>

> You can find that hand made puller, and how to use it, described in the

> pages of my PDF document... it describes the type of wire common in

> local hardware stores...and a common small bolt and nut.

>

> All the best,

> Michael

>

> On Oct 27, 2015 6:20 AM, "tom loeblt@... mailto:loeblt@...>

> [Losmandy_users]" Losmandy_users@yahoogroups.com

> mailto:Losmandy_users@yahoogroups.com>> wrote:

>

> __

>

> In one tough case I drilled a hole slightly larger in diameter than the

> inner bearing race on the rear of the block and tapped the bearing out

> with a drill bit. Odds are, if you do this, you will want to replace

> the

> bearing in case it gets damaged in the process.

>

> Tom

>

> On 10/27/2015 9:04 AM, buckeyestargazer@...

> mailto:buckeyestargazer@...> [Losmandy_users] wrote:

> >

> >

> > Arnold and David,

> > Arnold - I had to buy 10 washers in a pack so I've got several to

> spare

> > and I can send you a couple.

> > David - If you want to try and rebuild the motor again I have a new

> > spare motor (just the motor, not the encoder or housing). Or, I have

> > been considering upgrading my DEC motor to the HT motor. I would need

> > to find a HT motor first before letting the old one go.

> >

> > Can we send private messages on here? I couldn't find an option

> to do so.

> >

> > Also, can the HT motor just be swapped out with the original

> servo motor?

> >

> > Regarding using the Bellville washer on the old two block worm

> bearing,

> > I was going to try that myself since I've got plenty of washers.

> I have

> > the old two block housing on the DEC axis (OPW on the RA). But I

> > couldn't get the bearing out of the block housing. Does anyone have

> > tips for removing the bearing? I tried Michael's method in the PDF

> > document but I still couldn't get enough pull to remove it.

> > joel

> >

> >

> >

>

> --

> Tom

>

>

>

>



--

Tom







----------------------------

#56389 Oct 31, 2015

Super...I am happy to read that!My request is this:Please measure your PE before and after you upgrade your system, under similar conditions and settings.Then our group will get a sense of potential improvements (I hope!) from these simple modifications.It does take about an hour or so to get the PE raw data.. (You'd rather be imaging something!) You need to get a drift polar alignment first...that is normally my longest effort... After you calibrate your free PHD (better: PHD2 software is really super...and also free) guiding software (using Guide mode on the hand or Gemini controller...of course, and PHD output on, so PHD knows E W N S directions...RA and DEC, etc), you need to turn off guide output, and let PHD just log unguided star tracking of about 3 or more periods of the worm...on G11 they are 4 minutes each.. And waiting for a clear sky...is unpredictable too....I give a free easy way to extract the PE in that same writeup from PHD guide log files... That is because other wonderful amateurs gave us nice Fourier transform analysis software... they even built in the gear timings for the G11 (and Orion Atlas/Synta EQ6...and other mounts).. See my PDF if you need a walk through, or where to download the software. ..Stay well and have fun,MichaelOn Oct 31, 2015 9:22 AM, "tom loeblt@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:

.I recently saw your document Michael. I have an extra worm block set and

I just received some of the washers. I will try your puller trick on the

bearings of blocks I had not drilled.



Tom



On 10/31/2015 12:09 PM, Michael Herman mherman346@...

[Losmandy_users] wrote:

>

>

> Hi Tom,

>

> Sorry that I missed your note on this issue of the hard to remove rear

> bearing...that will probably come up replacing bearings.

>

> The removal of the "frozen in" rear bearing ... should not need

> drilling of the rear bearing block to remove it.

>

> When I also could not get my rear worm bearing out of its block, I

> fashioned a simple puller out of some steel wire...wrapped around a bolt

> to hole the puller jaws.

>

> You can find that hand made puller, and how to use it, described in the

> pages of my PDF document... it describes the type of wire common in

> local hardware stores...and a common small bolt and nut.

>

> All the best,

> Michael

>

> On Oct 27, 2015 6:20 AM, "tom loeblt@... mailto:loeblt@...>

> [Losmandy_users]" Losmandy_users@yahoogroups.com

> mailto:Losmandy_users@yahoogroups.com>> wrote:

>

> __

>

> In one tough case I drilled a hole slightly larger in diameter than the

> inner bearing race on the rear of the block and tapped the bearing out

> with a drill bit. Odds are, if you do this, you will want to replace

> the

> bearing in case it gets damaged in the process.

>

> Tom

>

> On 10/27/2015 9:04 AM, buckeyestargazer@...

> mailto:buckeyestargazer@...> [Losmandy_users] wrote:

> >

> >

> > Arnold and David,

> > Arnold - I had to buy 10 washers in a pack so I've got several to

> spare

> > and I can send you a couple.

> > David - If you want to try and rebuild the motor again I have a new

> > spare motor (just the motor, not the encoder or housing). Or, I have

> > been considering upgrading my DEC motor to the HT motor. I would need

> > to find a HT motor first before letting the old one go.

> >

> > Can we send private messages on here? I couldn't find an option

> to do so.

> >

> > Also, can the HT motor just be swapped out with the original

> servo motor?

> >

> > Regarding using the Bellville washer on the old two block worm

> bearing,

> > I was going to try that myself since I've got plenty of washers.

> I have

> > the old two block housing on the DEC axis (OPW on the RA). But I

> > couldn't get the bearing out of the block housing. Does anyone have

> > tips for removing the bearing? I tried Michael's method in the PDF

> > document but I still couldn't get enough pull to remove it.

> > joel

> >

> >

> >

>

> --

> Tom

>

>

>

>



--

Tom



----------------------------

#56400 Nov 4, 2015

Looks like McMaster-Car product 3759T38 is very similar to the Boca Bearings and come in at about $10 each. The specs are: double-shielded, stainless steel, dia 1/4", OD 5/8", Wd. 0.196". Any reason that these wouldn't work?

Mark



----------------------------

#56401 Nov 4, 2015

Mark,Those are also spec'd as ABEC7 so they look like they'd work great also at $10 each.. Especially if you plan to order other stuff like Belleville washers... so the shipping costs are amortized. ...McMaster Carr adds domestic UPS shipping costs, while I think Boca Bearings (off eBay) offers free shipping.. So the apparent price difference of $3 higher from Boca Bearings might essentially be equivalent....just for a bearing order.Given that David Partridge used a different set of ABEC5 rated bearings and he got great results too, suggests replacing the stock bearings helps reduce PE measurably.. You will have to run the experiment with the McMaster Carr bearings and tell us what you get for PE before and after...Stay well, and let us know how your improvement efforts go...!Michael

...On Nov 4, 2015 10:22 AM, "tazercn@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:

.Looks like McMaster-Car product 3759T38 is very similar to the Boca Bearings and come in at about $10 each. The specs are: double-shielded, stainless steel, dia 1/4", OD 5/8", Wd. 0.196". Any reason that these wouldn't work?

Mark







----------------------------

#56402 Nov 4, 2015

Thanks for the feedback Michael. I'll go ahead and give those bearings a shot. There are 3 bearings total per worm, correct?��

Mark



----------------------------

#56403 Nov 4, 2015

Mark,



I'm in PA and McMaster has a warehouse in NJ. I usually get my order the next day if it's in stock.



Don

----- Original Message -----

From: "tazercn@... [Losmandy_users]" Losmandy_users@yahoogroups.com>

To: Losmandy_users@yahoogroups.com>

Sent: Wednesday, November 04, 2015 1:22 PM

Subject: [Losmandy_users] Re: Thanks to Michael Herman for tips to improve G11 PE





> Looks like McMaster-Car product 3759T38 is very similar to the Boca Bearings and come in at about

> $10 each. The specs are: double-shielded, stainless steel, dia 1/4", OD 5/8", Wd. 0.196". Any

> reason that these wouldn't work?

>

> Mark

>



----------------------------

#56404 Nov 4, 2015

If you have the OPW, there are 3 bearings (2 near the motor, one at the other end)..But in my OPW, I only replaced the two bearings surrounding the worm,. and got good results...with the spring washer also (like the Ovision system has)..I honestly can't recall if the original RA drive with 2 separated worm blocks needed 2 bearings in the front block or not... I'm away from home this week..... I can give that answer next week, when I can look at the original blocks. .... Sorry about that!I never replaced the DEC bearings, or its original steel worm...thinking that they should not affect PEC since that's an RA clocking issue.. ( I really should put a spring washer into my DEC worm, but I also suffer from the "if it isn't broken. ..." mentality.. ). The spring washer ensures the worm has no side to side movement, so it should eliminate unwanted time lags when the worm reverses direction..I look forward to hearing of your PE results...Stay well,

MichaelOn Nov 4, 2015 11:05 AM, "tazercn@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:

.Thanks for the feedback Michael. I'll go ahead and give those bearings a shot. There are 3 bearings total per worm, correct?.

Mark



----------------------------

#56405 Nov 4, 2015

Like Michael, I only replaced the two bearings (OPW) on either end of the worm gear and got good results.. The old two block system only uses one bearing in each block. .joel



----------------------------

#56406 Nov 4, 2015

Thanks again Michael. I'll keep everyone in the loop as to how the bearings fit and if I run into any gotchas.

I do have the OPW in RA and the standard worm block, with brass worm, in DEC. I went ahead and picked up 6 bearings and a pack of spring washers anyway. I figured if I'm going to preload the worm in DEC then I might as well go all the way. With DEC I want to eliminate axial travel as much as possible without having to squeeze the blocks too tight.

The OPW did decrease my PE. I believe with the two-piece it was 12-15" p2p and with the OPW it dropped to something like 5" p2p (both measurements without PEC). I'm not seeking a huge change in RA but better performance in general. I find that corrections in RA seem to indicate backlash, but even with the mount heavily loaded to the east I still get that behavior at times. I suspect it may be due in part to axial play.

I'll also take the opportunity to align the gear box properly as I've got a long period error that might be due to misalignment.

Mark



----------------------------

#56407 Nov 4, 2015

Excellent... and thanks to everyone contributing to this PE performance improvement effort.On a related issue...

I was also happy to get rid of a related problem...RA motor stalling.. I would follow the recommended tightening of the RA worm against the mount, until the RA counterweight bar end would wiggle 1 to 2 mm.. But then the darn RA would stall out from time to time.What the real problem was for me was the side to side movement of the RA worm between its bearing blocks.. Without the spring washer in place, that slippage allows probably 2 mm side to side alone in my system.. So I ended up over tightening that RA to Ring gear space...and my system would then stall out.. Once the spring washer was installed,. eliminating the side to side movement, then adjusting the RA worm gear gap so the end of the RA counterweight bar movement of only 1mm, gave me finally no stalling..So... here's hoping you also find additional benefits from this RA PE effort.

Best,

MichaelOn Nov 4, 2015 2:06 PM, "tazercn@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:

.Thanks again Michael. I'll keep everyone in the loop as to how the bearings fit and if I run into any gotchas.

I do have the OPW in RA and the standard worm block, with brass worm, in DEC. I went ahead and picked up 6 bearings and a pack of spring washers anyway. I figured if I'm going to preload the worm in DEC then I might as well go all the way. With DEC I want to eliminate axial travel as much as possible without having to squeeze the blocks too tight.

The OPW did decrease my PE. I believe with the two-piece it was 12-15" p2p and with the OPW it dropped to something like 5" p2p (both measurements without PEC). I'm not seeking a huge change in RA but better performance in general. I find that corrections in RA seem to indicate backlash, but even with the mount heavily loaded to the east I still get that behavior at times. I suspect it may be due in part to axial play.

I'll also take the opportunity to align the gear box properly as I've got a long period error that might be due to misalignment.

Mark



----------------------------

#56408 Nov 5, 2015

On 11/4/2015 6:21 PM, Michael Hermanmherman346@... [Losmandy_users] wrote:

.Excellent... and thanks to everyonecontributing to this PE performance improvement effort.On a related issue...

I was also happy to get rid of a related problem...RAmotor stalling.. I would follow the recommended tighteningof the RA worm against the mount, until the RAcounterweight bar end would wiggle 1 to 2 mm.. But thenthe darn RA would stall out from time to time.What the real problem was for me was the sideto side movement of the RA worm between its bearingblocks.. Without the spring washer in place, that slippageallows probably 2 mm side to side alone in my system.. SoI ended up over tightening that RA to Ring gearspace...and my system would then stall out.. Once thespring washer was installed,. eliminating the side to sidemovement, then adjusting the RA worm gear gap so the endof the RA counterweight bar movement of only 1mm, gave mefinally no stalling..So... here's hoping you also find additionalbenefits from this RA PE effort.

Best,

MichaelOn Nov 4, 2015 2:06 PM, "tazercn@...[Losmandy_users]" Losmandy_users@yahoogroups.com>wrote:

.Thanks again Michael. I'll keep everyone inthe loop as to how the bearings fit and if Irun into any gotchas.



I do have the OPW in RA and the standard wormblock, with brass worm, in DEC. I went ahead andpicked up 6 bearings and a pack of springwashers anyway. I figured if I'm going topreload the worm in DEC then I might as well goall the way. With DEC I want to eliminate axialtravel as much as possible without having tosqueeze the blocks too tight.

The OPW did decrease my PE. I believe withthe two-piece it was 12-15" p2p and with theOPW it dropped to something like 5" p2p (bothmeasurements without PEC). I'm not seeking ahuge change in RA but better performance ingeneral. I find that corrections in RA seem toindicate backlash, but even with the mountheavily loaded to the east I still get thatbehavior at times. I suspect it may be due inpart to axial play.

I'll also take the opportunity to align thegear box properly as I've got a long perioderror that might be due to misalignment.

Mark







----------------------------

#56409 Nov 5, 2015

Hi Jeff,Your emsil raises some good issues which have remained hidden from earlier discussions.One issue, that I think David Partridge wondered about is this: if the rear bearing is frozen or rusted into place, how can the spring washer keep it tight against the worm?.For the spring washer to work, the rear worm bearing has to be able to slide in the bearing block.. Most people find the bearing was pressed in, and needed a "puller" to yank it out of the rear block.. That can't slide!... but in the improved design with spring washer, it must be able to slide..I got mine to slide, but I am working from memory as to how...apologies.. I think I may have used a very fine polishing grade sand paper to clean the inside ID of the rear bearing block when I installed the new spring washer and bearing.. I put a lubricant around the outside of the bearing.. I likely used an automotive anti seize assembly lubricant...or a lithium based grease.. I did find the new bearing would slide axially from the (7 pound force) new spring washer..Over time, metal surfaces oxidize, and the extra oxygen atoms thicken the metal surface... causing the moving parts to have less gap, and over time to bind.. The lube keeps the metal atoms from cold welding...I don't think a slight increase in worm bearing block ID to allow the. bearing to slide will harm PE..My thinking is along these lines: even if the bearing edges were slightly smaller than the bearing block ID diameter, leaving a tiny gap, that bearing movement in the gap is perpendicular to the RA worm axis.. It won't affect PE because that gap will act the same as the RA worm to ring gap we intentionally put in to prevent worm stalling.. So even if you were to sand aound the inside of the bearing block to ensure the bearing slides axially, and lube the gap, it should have negligible effect on RA or PE...--------The 2nd thing is your comment about seeing a wild RA PE behavior... what could cause this? In earlier investigations, Michael Sinecalchi wrote about the Oldham coupler behavior...and concerns about off axis effects.. He didn't find a better performance from other types of couplers he tried.. But the system has to be closely on axis with the RA worm to keep out nonlinear effects.I also worried about keeping the system on axis.. So to hold the position of drive components, I cut and wound some small brass spacers to put around the motor mount screws (see the PDF for a description). That motor mount has larger holes than the mounting bolts, so you can position the motor.. But I was concerned that the motor gearbox bolts could loosen, so the drive would become off axis to the RA worm...causing an uneven RA effect.. The Oldham coupler catches any axial offsets and still drives the worm, but the two sliding Oldham parts might cause a PE effect.. So bottom line: see if your motor gearbox drive shaft is really well aligned with the RA worm axis...and nothing is loose....All the best,

Michael.On 11/4/2015 6:21 PM, Michael Herman mherman346@... [Losmandy_users] wrote:

>

> .

>

> Excellent... and thanks to everyone contributing to this PE performance improvement effort.

>

> On a related issue...

> I was also happy to get rid of a related problem...RA motor stalling.. I would follow the recommended tightening of the RA worm against the mount, until the RA counterweight bar end would wiggle 1 to 2 mm.. But then the darn RA would stall out from time to time.

>

> What the real problem was for me was the side to side movement of the RA worm between its bearing blocks.. Without the spring washer in place, that slippage allows probably 2 mm side to side alone in my system.. So I ended up over tightening that RA to Ring gear space...and my system would then stall out.. Once the spring washer was installed,. eliminating the side to side movement, then adjusting the RA worm gear gap so the end of the RA counterweight bar movement of only 1mm, gave me finally no stalling..

>

> So... here's hoping you also find additional benefits from this RA PE effort.

>

> Best,

> Michael

.On 11/4/2015 6:21 PM, Michael Hermanmherman346@... [Losmandy_users] wrote:

.Excellent... and thanks to everyonecontributing to this PE performance improvement effort.On a related issue...

I was also happy to get rid of a related problem...RAmotor stalling.. I would follow the recommended tighteningof the RA worm against the mount, until the RAcounterweight bar end would wiggle 1 to 2 mm.. But thenthe darn RA would stall out from time to time.What the real problem was for me was the sideto side movement of the RA worm between its bearingblocks.. Without the spring washer in place, that slippageallows probably 2 mm side to side alone in my system.. SoI ended up over tightening that RA to Ring gearspace...and my system would then stall out.. Once thespring washer was installed,. eliminating the side to sidemovement, then adjusting the RA worm gear gap so the endof the RA counterweight bar movement of only 1mm, gave mefinally no stalling..So... here's hoping you also find additionalbenefits from this RA PE effort.

Best,

MichaelOn Nov 4, 2015 2:06 PM, "tazercn@...[Losmandy_users]" Losmandy_users@yahoogroups.com>wrote:

.Thanks again Michael. I'll keep everyone inthe loop as to how the bearings fit and if Irun into any gotchas.



I do have the OPW in RA and the standard wormblock, with brass worm, in DEC. I went ahead andpicked up 6 bearings and a pack of springwashers anyway. I figured if I'm going topreload the worm in DEC then I might as well goall the way. With DEC I want to eliminate axialtravel as much as possible without having tosqueeze the blocks too tight.

The OPW did decrease my PE. I believe withthe two-piece it was 12-15" p2p and with theOPW it dropped to something like 5" p2p (bothmeasurements without PEC). I'm not seeking ahuge change in RA but better performance ingeneral. I find that corrections in RA seem toindicate backlash, but even with the mountheavily loaded to the east I still get thatbehavior at times. I suspect it may be due inpart to axial play.

I'll also take the opportunity to align thegear box properly as I've got a long perioderror that might be due to misalignment.

Mark







----------------------------

#56430 Nov 8, 2015

Greetings. Just wanted to give an update on my venture into this upgrade so far.��As mentioned previously, I picked up 6 of the ABEC-7 bearings from McMaster-Carr and the listed spring washers. Shipping was just under $6 so the average per bearing comes out to $11 for 6, or $12 if you only order 3.

The first thing I did was to upgrade the DEC bearings. I didn't expect much from it, but figured I might as well try. Unfortunately I had no success in DEC at all. It turns out that, for some reason, the new bearings don't sit as far into the blocks as the originals even though there's no clear size difference between them. They do fit nice and snug but when trying to remount the blocks they don't line up with the mounting holes. So, I reverted to the original bearings and a spring washer. No big deal as when the new OPWB is released I'll probably get one and move the RA OPWB to DEC.

Things went better in RA. The first thing I noticed when disassembling the OPWB was that it really is finely machined. The blocks come out easily and seemingly snap right back in place. I almost thought it was magnetic because there is no play in them but they go in place so easily. Anyway, the old bearings were very easily removed with one of those dentist like tools from Lowes:

www.lowes.com/pd_239658-930-324621N_0__?productId=1207839

The tip was already bent back so there was no scratching/scraping of the blocks or bearings. The old bearings weren't as snug as they were in the 2 piece block, so they came out easily. The new bearings & spring washer fit well and seated as deeply as the originals with a little detectable springiness with the worm mounted. The fully assembled OPWB fit back on the mount perfectly.��I did notice when disassembling the OPWB that one of the gearbox stand offs had come loose, so the gearbox wasn't as firmly seated as I'd thought it was. The worm would spin freely for a while but have a lot of tension at one point in the full revolution.

My first goal when putting things back together was to try to get the gearbox aligned just right. I'd seat the gearbox, tighten the set screws, and give the worm a spin but couldn't seem to get it right. While pondering my dilemma I gave the worm a spin and watched the oldham couple twirl. On a whim I spun the worm and stuck a thin allen wrench in. In a pottery making style, I kept spinning the worm and used the wrench to smooth out the wobble. After about 30s I had the coupler perfectly aligned and ready for the gearbox. I went back and forth a couple of times but ultimately ended up with a gearbox-to-worm alignment with almost completely consistent resistance when spinning it around. Not perfect but pretty much better than before.



The biggest problem I ran into is the head of one of the screws (the one that goes through the outer gearbox housing into the stand-off) stripped. I was able to work things out but it'll need to be replaced the next time I have to work on it. One of the screws that mounts the servo to the gearbox is also near to being stripped, so I'll need to replace that as well. Anyone know of Losmandy keeps stock on them? Or know the specs of them so I can purchase replacements independently?

As it stands now the updated OPWB is on and I've finished adjusting backlash. Interestingly, I seem to have less backlash than before. There's almost no discernible movement at the end of the CW shaft yet when slewing there's no hint of motors laboring nor are there any heavy duty sl messages. If all goes well I'll be able to do a guiding / PE test next weekend.

Mark



----------------------------

#58789 Feb 18 6:36 PM

My G11 is an old 90's version with original worm and worm bearings. I've got new bearings, spring washers and HP worm ready to install. Before I do that I thought I'd get a baseline for the mount and ran PHD2 guiding assistant. It looks poor to me. I'm interested in any insight anyone may have on what my be amiss with my G11, especially if new worm/bearings may not help.��

xa.yimg.com/df/Losmandy_users/phd2-1.png?token=wBz5LhDhzO_gVS2XQVKC3zQ98wpJGpHbTGFjLe-cMukx7QuEHwfa9_lfut9Wg1x-bY56iH2hzSs9-QllestFakmv0PPXcLVeqzPFr_jjiv306pe-raQskcKojmP7--I&amp;type=download



xa.yimg.com/df/Losmandy_users/phd2-1.png?token=w...



----------------------------

#58790 Feb 18 7:06 PM

Hi TMallan,

I see your graph of data, and clearly see it oscillating in RA.. But I cannot do anything with that mathematically to see what is going on.... I'd need your log file for that. .

Can you please send me your PHD2 log (text) file, with:

Your scope (aperture, Focal Length)Your guide camera (pixel X and Y um micron sizes)

to mherman346 at gmail dot com ?

The PHD2 logfile should already have in it where in the sky you were pointing. .[I find it best to point near the celestial equator and the meridian (N-S line) for best RA resolution. ]

Then I will run the free program PecPrep.exe from here:

eq-mod.sourceforge.net/pecprep/



You can download it from there of course, and select Mount type: G11Then the program knows your G11 worm and other standard gears.

That will analyze your data and show what part of your drive train is causing both periodic error (error in the worm period) and it will show what is left when you would employ the (free) PEC training that is built into say the Gemini systems.. It is the leftover "a-periodic" error that PEC cannot correct ahead of time, that would be left for your autoguider camera to try and correct.

Many people try to get the "periodic" part down to zero, so they don't even need to do PEC.. But it's the aperiodic errors that are more of a nuisance, because autoguiding corrects errors "after the fact" and those errors show up in the final photo. .

I have a document that explains the results of using that program, and other hardware changes, to improve my similar 1990s vintage "Celestron" G11 mount in the file Improving the Losmandy G11 OPW_v3_Aug_7_2016.pdf

It is in this file location belonging to our group:groups.yahoo.com/neo/groups/Losmandy_users/files/Michael%20Herman/



Anyway, let's see what you have so far, and consider where you can probably get. .

---------------Some related questions:

What type of imaging do you plan to do, and what is the biggest FL scope and heaviest scope you plan to use?

Do you plan to use long duration deep sky imaging or shorter like video imaging? .

Do you plan to use "piggyback" guiding for deep sky imaging, or use "Off Axis Guiding" OAG for that?

All the best,Michael







----------------------------

#58791 Feb 19 6:08 PM

For what it's worth, on all�� 5 of my Losmandy mounts I'd run a slightly loose worm/worm gear mesh.�� This consistently gave me the best performance.�� I typically shot 30 minute subs.

my 2 cents...

Eric



----------------------------

#58792 Feb 19 7:02 PM

I. must agree somewhat. My Titan mount seems impervious to my adjustments, it just works. The G8 is five years old and has never been adjusted.. The G11 I have had the longest gave me problems until upgraded the gearboxes. Now I just eyeball adjust it and it works. ��Leroy.............................................. ��From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com] Sent: Sunday, February 19, 2017 7:08 PMTo: Losmandy_users@yahoogroups.comSubject: [Losmandy_users] Re: Disappointing G11 performance



----------------------------

#58793 Feb 19 10:24 PM

Yes, loose is good for me too. Just make sure to load the worm bias towards the east. 10 minute subs all night, night after night without having to throw away any exposures. I have a two year old G11 that came stock with high precision worms. Love it.



John





On Monday, February 20, 2017 11:03 AM, "'Leroy Marion' lmarion@... [Losmandy_users]" Losmandy_users@yahoogroups.com> wrote:



��I�� must agree somewhat. My Titan mount seems impervious to my adjustments, it just works. The G8 is five years old and has never been adjusted.�� The G11 I have had the longest gave me problems until upgraded the gearboxes. Now I just eyeball adjust it and it works. ��Leroy�������������������������������������������������������������������������������������������� ��From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com] Sent: Sunday, February 19, 2017 7:08 PMTo: Losmandy_users@yahoogroups.comSubject: [Losmandy_users] Re: Disappointing G11 performance



----------------------------

#58794 Feb 20 5:14 AM

Eric, ��Have you found that running the worm/gear mesh slightly loose leads to longer settling times after a slew? ��Greg ��From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Monday, 20 February 2017 1:08 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Disappointing G11 performance



----------------------------

#58801 Feb 22 7:48 PM

Hi Greg,

I didn't really experience any settling issues.�� I generally loaded my mount slightly east heavy so that the worm was riding on one face of the gear through half the sky.�� When you meridian flip, you need to adjust the weight to continue the east heavy configuration and have it riding on the same side of the gear face.�� The weight bias keeps the worm tight against the gear so there is essentially no backlash.��

I found that when the worm mesh is too tight, the performance was quite poor vs. having it ever so slightly loose.�� I made a little manual tool to turn the worm, in place of the motor.�� That way I cold feel if the worm was smooth or needed to be loosened any further.�� I did this on all my losmandy mounts (Gm8 and G11's including one with an Ovision). The only mount that I owned that needed no adjustments was my AP Mach1GTO.

For what its worth, these are my G11 images:smu.gs/2l1URpw

Hope this helps.

Eric



----------------------------

#58806 Feb 23 7:16 AM

When meshing the worm and gear what do you feel/look for?



Thanks!



----------------------------

#60848 Feb 10 9:06 AM

Can anyone point me to a PEC file for the G11 that's either been pulled from the mount itself or created by Pempro.�� I'm trying to get familiar with Pempro V2 with respect to creating / uploading a PEC file to the new G11 mount I just bought.�� I realize it's not going to be useful for guiding, but weather forecast is bad for the next 10 days and I won't be able to create one from the mount / sky.Wayne



----------------------------

#60849 Feb 10 4:49 PM

I think Allen Ruckle may have something like that - i don't mean to volunteer him, but I know he's been working on PEC files for his G11. maybe he'll loan you one.

i'll ping him



BRIAn



----------------------------

#60851 Feb 11 9:37 PM

Hallelujah the skies have cleared for a night and I'm acquiring a PE curve via Pempro.�� No need to dig up your buddies curve.�� Thanks for offering though.Wayne��



Contact Us
This Site's Privacy Policy
Google's privacy policies

S
e
n
i
o
r
T
u
b
e
.
o
r
g