VintageBigBlue.org

 

RE: [Losmandy_users] PE Specs was Re: 1 complete worm period, no PEC or guiding, G-11 Gemini


Jul 23, 2008

 


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

#38432 Jul 23, 2008

Well, I have been working for two nights trying to get a log of my PE

on the G-11 Gemini. Many problems due to conditions and inability to

see east or west to get a good alignment and polar alignment in the

back yard.

However, after working on the polar alignment for one night and then

taking a log on the second, I got a complete worm cycle plus a little

in PHD and then had PEAS decipher it and put PE into arc seconds based

on pixel size and focal length.

The PEC was off and the guiding was turned off as well. I was only

able to get one worm period at a time without too much drift, so I

decided this would have to do.

This link to my photos shows the graph, which to my amazement, looks

like 4"-5" peak to peak with a fairly smooth wave.

Now I am not sure whether to even consider the Ovision worm block!

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

Then I decided to take a 6 minute unguided image to see what it was

like. It had round stars and no trails, though the picture really

sucked due to light pollution, over exposure and the camera being at

30.c because the cooling was not on due to dew point being high and

having it dew up the night before when I tried to cool to 10.c. :^)

Not sure what to make of the data, but it is the best that I can

muster without spending a bit on software to get Pempro to work.

Floyd



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

#38434 Jul 23, 2008

Wow Floyd!

It seems excellent.

Rosario

www.astromaster.org ----- Original Message -----

From: Floyd Blue

To: Losmandy_users@yahoogroups.com

Sent: Wednesday, July 23, 2008 9:51 PM

Subject: [Losmandy_users] 1 complete worm period, no PEC or guiding, G-11 Gemini





Well, I have been working for two nights trying to get a log of my PE

on the G-11 Gemini. Many problems due to conditions and inability to

see east or west to get a good alignment and polar alignment in the

back yard.

However, after working on the polar alignment for one night and then

taking a log on the second, I got a complete worm cycle plus a little

in PHD and then had PEAS decipher it and put PE into arc seconds based

on pixel size and focal length.

The PEC was off and the guiding was turned off as well. I was only

able to get one worm period at a time without too much drift, so I

decided this would have to do.

This link to my photos shows the graph, which to my amazement, looks

like 4"-5" peak to peak with a fairly smooth wave.

Now I am not sure whether to even consider the Ovision worm block!

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

Then I decided to take a 6 minute unguided image to see what it was

like. It had round stars and no trails, though the picture really

sucked due to light pollution, over exposure and the camera being at

30.c because the cooling was not on due to dew point being high and

having it dew up the night before when I tried to cool to 10.c. :^)

Not sure what to make of the data, but it is the best that I can

muster without spending a bit on software to get Pempro to work.

Floyd











[Non-text portions of this message have been removed]



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

#38436 Jul 23, 2008

Floyd,







The results you got mirror my last evaluation of my mount that I did

last year with a demo of Pempro.







Since then they produced a version 2 and I decided to buy it because of a

few extra features such as the starfinder, backlash exerciser, and most

importantly the Polar Alignment wizard (which requires a view of the

celestial equator and the western horizon.







So, at this point I.m not exactly ready to buy a new worm.







As to your mount, my recommendation is to take it outside with a southern

exposure and use pempro (You can use the 60 day free trial or buy it) and

program in your PEC. Once it.s in it should be good indefinitely. Then you

can take it back inside to set up on your balcony.







I would not touch or replace that worm except to perhaps grease it. I use

synthetic marine grease. I grease every other year. I pull off the ring that

covers the gear as well as the worm cover. Then I wipe off as much grease as

possible before liberally smearing new grease across the gears and the worm.







Which brings up another point. Has anyone experimented with different grease

when there.s unpredictable frequency problems with the worm? I.d bet that

dirty grease could cause some of these errors.







Tom P.















From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

On Behalf Of Rosario

Sent: Wednesday, July 23, 2008 4:17 PM

To: Losmandy_users@yahoogroups.com

Subject: Re: [Losmandy_users] 1 complete worm period, no PEC or guiding,

G-11 Gemini







Wow Floyd!

It seems excellent.

Rosario

www.astromaster.org ----- Original Message -----

From: Floyd Blue

To: Losmandy_users@yahoogroups.com mailto:Losmandy_users%40yahoogroups.com>



Sent: Wednesday, July 23, 2008 9:51 PM

Subject: [Losmandy_users] 1 complete worm period, no PEC or guiding, G-11

Gemini



Well, I have been working for two nights trying to get a log of my PE

on the G-11 Gemini. Many problems due to conditions and inability to

see east or west to get a good alignment and polar alignment in the

back yard.

However, after working on the polar alignment for one night and then

taking a log on the second, I got a complete worm cycle plus a little

in PHD and then had PEAS decipher it and put PE into arc seconds based

on pixel size and focal length.

The PEC was off and the guiding was turned off as well. I was only

able to get one worm period at a time without too much drift, so I

decided this would have to do.

This link to my photos shows the graph, which to my amazement, looks

like 4"-5" peak to peak with a fairly smooth wave.

Now I am not sure whether to even consider the Ovision worm block!

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

Then I decided to take a 6 minute unguided image to see what it was

like. It had round stars and no trails, though the picture really

sucked due to light pollution, over exposure and the camera being at

30.c because the cooling was not on due to dew point being high and

having it dew up the night before when I tried to cool to 10.c. :^)

Not sure what to make of the data, but it is the best that I can

muster without spending a bit on software to get Pempro to work.

Floyd



[Non-text portions of this message have been removed]











[Non-text portions of this message have been removed]







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

#38437 Jul 23, 2008

This the brass worm Floyd? What vintage is the mount?



I'll let the experts here weigh in on whether there's any sub-cycle

elements but Mark's point about measuring before buying certainly

seems valid.



One thing about it is that I'd never want to touch those bearing

blocks, ever. It might take an eternity to get them that well lined

up again.



regards

Greg N



--- In Losmandy_users@yahoogroups.com, "Rosario" rosario.pomillo@...>

wrote: >

> Wow Floyd!

> It seems excellent.

> Rosario

> www.astromaster.org

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

> From: Floyd Blue

> To: Losmandy_users@yahoogroups.com

> Sent: Wednesday, July 23, 2008 9:51 PM

> Subject: [Losmandy_users] 1 complete worm period, no PEC or

guiding, G-11 Gemini >

>

> Well, I have been working for two nights trying to get a log of my PE

> on the G-11 Gemini. Many problems due to conditions and inability to

> see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a little

> in PHD and then had PEAS decipher it and put PE into arc seconds based

> on pixel size and focal length.

> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.

> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13 > Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>

>

>

>

>

> [Non-text portions of this message have been removed]

>



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

#38438 Jul 23, 2008

Hi Thomas,

Thanks for the reply and your own testing results. This seems to

confirm that my data was probably sound.

The only problem with PemPro is that you must have CCDSoft or MaximDL

to use it from what I understand. I use Nebulosity and Envisage with

my DSI III Pro. The cost of Maxim is more than I wish to spend and

CCDSoft does not support the DSI at this time, though I hear they are

going to do so soon.

My mount is only a year old and the grease looks good and it is still

clean. I will wait until next year and look again.

I have heard the the Mobil Synthetic grease is suppose to be quite

good and readily available at most good parts stores.

Floyd

--- In Losmandy_users@yahoogroups.com, "Thomas Picciani"

tpicciani@...> wrote: >

> Floyd,

>

>

>

> The results you got mirror my last evaluation of my mount that

I did > last year with a demo of Pempro.

>

>

>

> Since then they produced a version 2 and I decided to buy it because

of a > few extra features such as the starfinder, backlash exerciser, and most

> importantly the Polar Alignment wizard (which requires a view of the

> celestial equator and the western horizon.

>

>

>

> So, at this point I'm not exactly ready to buy a new worm.

>

>

>

> As to your mount, my recommendation is to take it outside with a

southern > exposure and use pempro (You can use the 60 day free trial or buy

it) and > program in your PEC. Once it's in it should be good indefinitely.

Then you > can take it back inside to set up on your balcony.

>

>

>

> I would not touch or replace that worm except to perhaps grease it.

I use > synthetic marine grease. I grease every other year. I pull off the

ring that > covers the gear as well as the worm cover. Then I wipe off as much

grease as > possible before liberally smearing new grease across the gears and

the worm. >

>

>

> Which brings up another point. Has anyone experimented with

different grease > when there's unpredictable frequency problems with the worm? I'd bet

that > dirty grease could cause some of these errors.

>

>

>

> Tom P.

>

>

>

>

>

>

>

> From: Losmandy_users@yahoogroups.com

[mailto:Losmandy_users@yahoogroups.com] > On Behalf Of Rosario

> Sent: Wednesday, July 23, 2008 4:17 PM

> To: Losmandy_users@yahoogroups.com

> Subject: Re: [Losmandy_users] 1 complete worm period, no PEC or guiding,

> G-11 Gemini

>

>

>

> Wow Floyd!

> It seems excellent.

> Rosario

> www.astromaster.org

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

> From: Floyd Blue

> To: Losmandy_users@yahoogroups.com

mailto:Losmandy_users%40yahoogroups.com> >

> Sent: Wednesday, July 23, 2008 9:51 PM

> Subject: [Losmandy_users] 1 complete worm period, no PEC or guiding,

G-11 > Gemini

>

> Well, I have been working for two nights trying to get a log of my PE

> on the G-11 Gemini. Many problems due to conditions and inability to

> see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a little

> in PHD and then had PEAS decipher it and put PE into arc seconds based

> on pixel size and focal length.

> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.

> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13 > Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>

> [Non-text portions of this message have been removed]

>

>

>

>

>

> [Non-text portions of this message have been removed]

>







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

#38439 Jul 23, 2008

Thanks Rosario,

I was pleased and rather amazed at how well this stock mount works.

Certainly not an AP900, but it is very acceptable for the cost.

Floyd

--- In Losmandy_users@yahoogroups.com, "Rosario" rosario.pomillo@...>

wrote: >

> Wow Floyd!

> It seems excellent.

> Rosario

> www.astromaster.org

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

> From: Floyd Blue

> To: Losmandy_users@yahoogroups.com

> Sent: Wednesday, July 23, 2008 9:51 PM

> Subject: [Losmandy_users] 1 complete worm period, no PEC or

guiding, G-11 Gemini >

>

> Well, I have been working for two nights trying to get a log of my PE

> on the G-11 Gemini. Many problems due to conditions and inability to

> see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a little

> in PHD and then had PEAS decipher it and put PE into arc seconds based

> on pixel size and focal length.

> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.

> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13 > Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>

>

>

>

>

> [Non-text portions of this message have been removed]

>



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

#38441 Jul 23, 2008

You can dl Maxim for free for 30 days. J Of course, once you see how easy it

is to use, you.ll just have to have it permanently.







From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

On Behalf Of Floyd Blue

Sent: Wednesday, July 23, 2008 4:59 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: 1 complete worm period, no PEC or guiding,

G-11 Gemini







Hi Thomas,

Thanks for the reply and your own testing results. This seems to

confirm that my data was probably sound.

The only problem with PemPro is that you must have CCDSoft or MaximDL

to use it from what I understand. I use Nebulosity and Envisage with

my DSI III Pro. The cost of Maxim is more than I wish to spend and

CCDSoft does not support the DSI at this time, though I hear they are

going to do so soon.

My mount is only a year old and the grease looks good and it is still

clean. I will wait until next year and look again.

I have heard the the Mobil Synthetic grease is suppose to be quite

good and readily available at most good parts stores.

Floyd

--- In Losmandy_users@yahoogroups.com

mailto:Losmandy_users%40yahoogroups.com> , "Thomas Picciani"

tpicciani@...> wrote: >

> Floyd,

>

>

>

> The results you got mirror my last evaluation of my mount that

I did > last year with a demo of Pempro.

>

>

>

> Since then they produced a version 2 and I decided to buy it because

of a > few extra features such as the starfinder, backlash exerciser, and most

> importantly the Polar Alignment wizard (which requires a view of the

> celestial equator and the western horizon.

>

>

>

> So, at this point I'm not exactly ready to buy a new worm.

>

>

>

> As to your mount, my recommendation is to take it outside with a

southern > exposure and use pempro (You can use the 60 day free trial or buy

it) and > program in your PEC. Once it's in it should be good indefinitely.

Then you > can take it back inside to set up on your balcony.

>

>

>

> I would not touch or replace that worm except to perhaps grease it.

I use > synthetic marine grease. I grease every other year. I pull off the

ring that > covers the gear as well as the worm cover. Then I wipe off as much

grease as > possible before liberally smearing new grease across the gears and

the worm. >

>

>

> Which brings up another point. Has anyone experimented with

different grease > when there's unpredictable frequency problems with the worm? I'd bet

that > dirty grease could cause some of these errors.

>

>

>

> Tom P.

>

>

>

>

>

>

>

> From: Losmandy_users@yahoogroups.com

mailto:Losmandy_users%40yahoogroups.com>

[mailto:Losmandy_users@yahoogroups.com

mailto:Losmandy_users%40yahoogroups.com> ] > On Behalf Of Rosario

> Sent: Wednesday, July 23, 2008 4:17 PM

> To: Losmandy_users@yahoogroups.com

mailto:Losmandy_users%40yahoogroups.com> > Subject: Re: [Losmandy_users] 1 complete worm period, no PEC or guiding,

> G-11 Gemini

>

>

>

> Wow Floyd!

> It seems excellent.

> Rosario

> www.astromaster.org

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

> From: Floyd Blue

> To: Losmandy_users@yahoogroups.com

mailto:Losmandy_users%40yahoogroups.com>

mailto:Losmandy_users%40yahoogroups.com> >

> Sent: Wednesday, July 23, 2008 9:51 PM

> Subject: [Losmandy_users] 1 complete worm period, no PEC or guiding,

G-11 > Gemini

>

> Well, I have been working for two nights trying to get a log of my PE

> on the G-11 Gemini. Many problems due to conditions and inability to

> see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a little

> in PHD and then had PEAS decipher it and put PE into arc seconds based

> on pixel size and focal length.

> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.

> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13 > Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>

> [Non-text portions of this message have been removed]

>

>

>

>

>

> [Non-text portions of this message have been removed]

>











[Non-text portions of this message have been removed]







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

#38442 Jul 23, 2008

Hi Greg,

Yes, it is indeed the brass worm. It was purchased new from OPT

2/2007. Not sure exactly when it was made, but probably not too long

before it was sold.



Here is my take on the adjustment with these blocks. I have done this

twice so far, once for winter and now just two days ago, for the summer.



I found that the blocks line up well when I use a fairly simple

method. Not trying to make like I am the expert here, but the graph

shows what mine was like right after I adjusted the RA worm.



I find that if you remove the cover and then loosen the bolt at the

gearbox end slightly, then loosen the far end and then use a feeler

gauge to set the worm. I put my thumb on the end of the block, then

with my forefinger I press the block toward the worm and toward the

mount against the feeler gauge and tighten the far end bolt snugly.

Then I tighten the gear box end snugly and check the lash. I then add

.001" or remove .001" from the feeler gauge until I get the lash

right. Next I put the cover back on and then I loosen the gear box end

block and let the block align to the other, releasing any angular

tension between the blocks, tighten it and check the lash again. If it

feels right, I make sure I tighten the blocks equally but not too tight.



This has worked for me each time and seems to set the end play and

blocks are aligned well.



It would be nice if the blocks were one unit, but they are not, so I

just deal with it.

:^)

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> This the brass worm Floyd? What vintage is the mount?

>

> I'll let the experts here weigh in on whether there's any sub-cycle

> elements but Mark's point about measuring before buying certainly

> seems valid.

>

> One thing about it is that I'd never want to touch those bearing

> blocks, ever. It might take an eternity to get them that well lined

> up again.

>

> regards

> Greg N

>

> --- In Losmandy_users@yahoogroups.com, "Rosario" rosario.pomillo@>

> wrote:

> >

> > Wow Floyd!

> > It seems excellent.

> > Rosario

> > www.astromaster.org

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

> > From: Floyd Blue

> > To: Losmandy_users@yahoogroups.com

> > Sent: Wednesday, July 23, 2008 9:51 PM

> > Subject: [Losmandy_users] 1 complete worm period, no PEC or

> guiding, G-11 Gemini

> >

> >

> > Well, I have been working for two nights trying to get a log of

my PE

> > on the G-11 Gemini. Many problems due to conditions and inability to

> > see east or west to get a good alignment and polar alignment in the

> > back yard.

> > However, after working on the polar alignment for one night and then

> > taking a log on the second, I got a complete worm cycle plus a

little

> > in PHD and then had PEAS decipher it and put PE into arc seconds

based

> > on pixel size and focal length.

> > The PEC was off and the guiding was turned off as well. I was only

> > able to get one worm period at a time without too much drift, so I

> > decided this would have to do.

> > This link to my photos shows the graph, which to my amazement, looks

> > like 4"-5" peak to peak with a fairly smooth wave.

> > Now I am not sure whether to even consider the Ovision worm block!

> >

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

> > Then I decided to take a 6 minute unguided image to see what it was

> > like. It had round stars and no trails, though the picture really

> > sucked due to light pollution, over exposure and the camera being at

> > 30.c because the cooling was not on due to dew point being high and

> > having it dew up the night before when I tried to cool to 10.c. :^)

> > Not sure what to make of the data, but it is the best that I can

> > muster without spending a bit on software to get Pempro to work.

> > Floyd

> >

> >

> >

> >

> >

> > [Non-text portions of this message have been removed]

> >

>



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

#38443 Jul 23, 2008

Floyd,



I sent a email to Software Bisque about a year ago asking if they were going to support the DSI

cameras and was told emphatically that they will never support any Meade product. Seems they had

provided support for the Pictor cameras and Meade sued them. I did mention to them they were loosing

potential customers as the DSI's were selling like hotcakes and there was a need for third party

image acquisition and processing. If they have changed their minds I'll be pissed as I've had

CCDSoft since version 4 and just recently purchased a used copy of MaxImDL.



Don

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

From: "Floyd Blue" fblue@...>

To: Losmandy_users@yahoogroups.com>

Sent: Wednesday, July 23, 2008 4:59 PM

Subject: [Losmandy_users] Re: 1 complete worm period, no PEC or guiding, G-11 Gemini





Hi Thomas,

Thanks for the reply and your own testing results. This seems to

confirm that my data was probably sound.

The only problem with PemPro is that you must have CCDSoft or MaximDL

to use it from what I understand. I use Nebulosity and Envisage with

my DSI III Pro. The cost of Maxim is more than I wish to spend and

CCDSoft does not support the DSI at this time, though I hear they are

going to do so soon.

My mount is only a year old and the grease looks good and it is still

clean. I will wait until next year and look again.

I have heard the the Mobil Synthetic grease is suppose to be quite

good and readily available at most good parts stores.

Floyd







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

#38444 Jul 23, 2008

I actually had Maxim for a while, but it did not work well with my DSI

II that I had at the time. SO, I sent it back. The colors were just

not right with the DSI II C one shot color.

Now I use a Mono DSI III Pro, maybe it would work better, but at over

$400 for Maxim and $150 for Pempro, I am just not that interested at

this time.

If CCDSoft comes out with support for the DSI III, I may try it.

Floyd

--- In Losmandy_users@yahoogroups.com, "Thomas Picciani"

tpicciani@...> wrote: >

> You can dl Maxim for free for 30 days. J Of course, once you see how

easy it > is to use, you'll just have to have it permanently.

>

>

>

> From: Losmandy_users@yahoogroups.com

[mailto:Losmandy_users@yahoogroups.com] > On Behalf Of Floyd Blue

> Sent: Wednesday, July 23, 2008 4:59 PM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] Re: 1 complete worm period, no PEC or guiding,

> G-11 Gemini

>

>

>

> Hi Thomas,

> Thanks for the reply and your own testing results. This seems to

> confirm that my data was probably sound.

> The only problem with PemPro is that you must have CCDSoft or MaximDL

> to use it from what I understand. I use Nebulosity and Envisage with

> my DSI III Pro. The cost of Maxim is more than I wish to spend and

> CCDSoft does not support the DSI at this time, though I hear they are

> going to do so soon.

> My mount is only a year old and the grease looks good and it is still

> clean. I will wait until next year and look again.

> I have heard the the Mobil Synthetic grease is suppose to be quite

> good and readily available at most good parts stores.

> Floyd

> --- In Losmandy_users@yahoogroups.com

> mailto:Losmandy_users%40yahoogroups.com> , "Thomas Picciani"

> tpicciani@> wrote:

> >

> > Floyd,

> >

> >

> >

> > The results you got mirror my last evaluation of my mount that

> I did

> > last year with a demo of Pempro.

> >

> >

> >

> > Since then they produced a version 2 and I decided to buy it because

> of a

> > few extra features such as the starfinder, backlash exerciser, and

most > > importantly the Polar Alignment wizard (which requires a view of the

> > celestial equator and the western horizon.

> >

> >

> >

> > So, at this point I'm not exactly ready to buy a new worm.

> >

> >

> >

> > As to your mount, my recommendation is to take it outside with a

> southern

> > exposure and use pempro (You can use the 60 day free trial or buy

> it) and

> > program in your PEC. Once it's in it should be good indefinitely.

> Then you

> > can take it back inside to set up on your balcony.

> >

> >

> >

> > I would not touch or replace that worm except to perhaps grease it.

> I use

> > synthetic marine grease. I grease every other year. I pull off the

> ring that

> > covers the gear as well as the worm cover. Then I wipe off as much

> grease as

> > possible before liberally smearing new grease across the gears and

> the worm.

> >

> >

> >

> > Which brings up another point. Has anyone experimented with

> different grease

> > when there's unpredictable frequency problems with the worm? I'd bet

> that

> > dirty grease could cause some of these errors.

> >

> >

> >

> > Tom P.

> >

> >

> >

> >

> >

> >

> >

> > From: Losmandy_users@yahoogroups.com

> mailto:Losmandy_users%40yahoogroups.com>

> [mailto:Losmandy_users@yahoogroups.com

> mailto:Losmandy_users%40yahoogroups.com> ]

> > On Behalf Of Rosario

> > Sent: Wednesday, July 23, 2008 4:17 PM

> > To: Losmandy_users@yahoogroups.com

> mailto:Losmandy_users%40yahoogroups.com>

> > Subject: Re: [Losmandy_users] 1 complete worm period, no PEC or

guiding, > > G-11 Gemini

> >

> >

> >

> > Wow Floyd!

> > It seems excellent.

> > Rosario

> > www.astromaster.org

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

> > From: Floyd Blue

> > To: Losmandy_users@yahoogroups.com

> mailto:Losmandy_users%40yahoogroups.com>

> mailto:Losmandy_users%40yahoogroups.com>

> >

> > Sent: Wednesday, July 23, 2008 9:51 PM

> > Subject: [Losmandy_users] 1 complete worm period, no PEC or guiding,

> G-11

> > Gemini

> >

> > Well, I have been working for two nights trying to get a log of my PE

> > on the G-11 Gemini. Many problems due to conditions and inability to

> > see east or west to get a good alignment and polar alignment in the

> > back yard.

> > However, after working on the polar alignment for one night and then

> > taking a log on the second, I got a complete worm cycle plus a little

> > in PHD and then had PEAS decipher it and put PE into arc seconds based

> > on pixel size and focal length.

> > The PEC was off and the guiding was turned off as well. I was only

> > able to get one worm period at a time without too much drift, so I

> > decided this would have to do.

> > This link to my photos shows the graph, which to my amazement, looks

> > like 4"-5" peak to peak with a fairly smooth wave.

> > Now I am not sure whether to even consider the Ovision worm block!

> >

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13 > > Then I decided to take a 6 minute unguided image to see what it was

> > like. It had round stars and no trails, though the picture really

> > sucked due to light pollution, over exposure and the camera being at

> > 30.c because the cooling was not on due to dew point being high and

> > having it dew up the night before when I tried to cool to 10.c. :^)

> > Not sure what to make of the data, but it is the best that I can

> > muster without spending a bit on software to get Pempro to work.

> > Floyd

> >

> > [Non-text portions of this message have been removed]

> >

> >

> >

> >

> >

> > [Non-text portions of this message have been removed]

> >

>

>

>

>

>

> [Non-text portions of this message have been removed]

>







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

#38447 Jul 23, 2008

Hi Floyd,

That's an amazing PE curve! Looks like about 4 arc seconds p-p to me.

Thanks for the info. I'm getting interested in this mount.



Could you please post the 5 minute unguided exposure (full size . no

Yahoo compression, in the Files) , and info the scope focal length,

camera (or chip) and the image scale (arc seconds per pixel) for us?

Thanks.



Clear skies,



Dennis Persyk

Igloo Observatory Home Page dpersyk.home.att.net

Hampshire, IL

Pier Design home.att.net/~dpersyk/Pier_Design.htm



--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

>

> Well, I have been working for two nights trying to get a log of my

PE on the G-11 Gemini. Many problems due to conditions and inability

to see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a

little in PHD and then had PEAS decipher it and put PE into arc

seconds based on pixel size and focal length.



> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.



> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?

b=13

> Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>



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

#38448 Jul 23, 2008

Floyd, that looks like a good result.



Have you looked at the frequency analysis in PEAS? It should tell you if the

76 sec error is present, if it is then PEC may be a non-starter for you

despite the low total PE. Mind you one cycle is a bit of a small small for

the software to work with.



One other thing, basic and you probably have it covered, but was the guide

near 0 dec, and if not did you feed the dec value into PEAS? I have also

found that PEAS is very good at resetting it parameters back to values other

than what you intend :)



Regards

Mark





[Non-text portions of this message have been removed]



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

#38449 Jul 23, 2008

Floyd,



The DSI and DSI II are now supported in CCDSoft5 by an ASCOM plug-in available here.

www.grbsystems.com/dsidriver.htm



Don

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

From: "Floyd Blue" fblue@...>

To: Losmandy_users@yahoogroups.com>

Sent: Wednesday, July 23, 2008 4:59 PM

Subject: [Losmandy_users] Re: 1 complete worm period, no PEC or guiding, G-11 Gemini





Hi Thomas,

Thanks for the reply and your own testing results. This seems to

confirm that my data was probably sound.

The only problem with PemPro is that you must have CCDSoft or MaximDL

to use it from what I understand. I use Nebulosity and Envisage with

my DSI III Pro. The cost of Maxim is more than I wish to spend and

CCDSoft does not support the DSI at this time, though I hear they are

going to do so soon.

My mount is only a year old and the grease looks good and it is still

clean. I will wait until next year and look again.

I have heard the the Mobil Synthetic grease is suppose to be quite

good and readily available at most good parts stores.

Floyd



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

#38451 Jul 23, 2008

Hi Dennis,

Yeah, I can post the photo, but I warn you it is not pretty. :^) But

it is good enough to see how the mount was working. My camera does not

do well at 30.c, it is pretty noisy.

I will post it with a link later. I will do a little post processing

to make it appear a little better, but I won't do anything to try to

improve it, just make it easier to see.

Floyd

--- In Losmandy_users@yahoogroups.com, "Dennis Persyk" dpersyk@...>

wrote: >

> Hi Floyd,

> That's an amazing PE curve! Looks like about 4 arc seconds p-p to me.

> Thanks for the info. I'm getting interested in this mount.

>

> Could you please post the 5 minute unguided exposure (full size . no

> Yahoo compression, in the Files) , and info the scope focal length,

> camera (or chip) and the image scale (arc seconds per pixel) for us?

> Thanks.

>

> Clear skies,

>

> Dennis Persyk

> Igloo Observatory Home Page dpersyk.home.att.net

> Hampshire, IL

> Pier Design home.att.net/~dpersyk/Pier_Design.htm

>

>

> --- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@> wrote:

> >

> > Well, I have been working for two nights trying to get a log of my

> PE on the G-11 Gemini. Many problems due to conditions and inability

> to see east or west to get a good alignment and polar alignment in the

> > back yard.

> > However, after working on the polar alignment for one night and then

> > taking a log on the second, I got a complete worm cycle plus a

> little in PHD and then had PEAS decipher it and put PE into arc

> seconds based on pixel size and focal length.

>

> > The PEC was off and the guiding was turned off as well. I was only

> > able to get one worm period at a time without too much drift, so I

> > decided this would have to do.

>

> > This link to my photos shows the graph, which to my amazement, looks

> > like 4"-5" peak to peak with a fairly smooth wave.

> > Now I am not sure whether to even consider the Ovision worm block!

> >

> tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?

> b=13

> > Then I decided to take a 6 minute unguided image to see what it was

> > like. It had round stars and no trails, though the picture really

> > sucked due to light pollution, over exposure and the camera being at

> > 30.c because the cooling was not on due to dew point being high and

> > having it dew up the night before when I tried to cool to 10.c. :^)

> > Not sure what to make of the data, but it is the best that I can

> > muster without spending a bit on software to get Pempro to work.

> > Floyd

> >

>







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

#38453 Jul 23, 2008

Hi Mark,

I did look at the frequency and could see no repetitive spikes at 76

sec or really anything that was repeating at a steady rate. SO, no, I

do not think the 76 sec error is present.

Yes, I added the DEC of the star in PEAS.

Agreed, more than one worm period would be nice, but I was having

enough problems just getting one without drift, so I just accepted

what I could do. :^)

I was just wanting to know how well I did on the worm adjustment as

much as anything and of course trying to get an idea of whether I

needed to consider the Ovision block or the other Martin Block.

Floyd

--- In Losmandy_users@yahoogroups.com, "Mark Crossley" public@...> wrote:

>

> Floyd, that looks like a good result.

>

> Have you looked at the frequency analysis in PEAS? It should tell

you if the

> 76 sec error is present, if it is then PEC may be a non-starter for you

> despite the low total PE. Mind you one cycle is a bit of a small

small for

> the software to work with.

>

> One other thing, basic and you probably have it covered, but was the

guide

> near 0 dec, and if not did you feed the dec value into PEAS? I have also

> found that PEAS is very good at resetting it parameters back to

values other

> than what you intend :)

>

> Regards

> Mark

>

>

> [Non-text portions of this message have been removed]

>



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

#38454 Jul 23, 2008

Thanks Don,

That is good news, though I do not use ASCOM, I could I guess.

Floyd --- In Losmandy_users@yahoogroups.com, "Don D'Egidio" djd521@...> wrote:

>

> Floyd,

>

> The DSI and DSI II are now supported in CCDSoft5 by an ASCOM plug-in

available here.

> www.grbsystems.com/dsidriver.htm

>

> Don

>

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

> From: "Floyd Blue" fblue@...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Wednesday, July 23, 2008 4:59 PM

> Subject: [Losmandy_users] Re: 1 complete worm period, no PEC or

guiding, G-11 Gemini

>

>

> Hi Thomas,

> Thanks for the reply and your own testing results. This seems to

> confirm that my data was probably sound.

> The only problem with PemPro is that you must have CCDSoft or MaximDL

> to use it from what I understand. I use Nebulosity and Envisage with

> my DSI III Pro. The cost of Maxim is more than I wish to spend and

> CCDSoft does not support the DSI at this time, though I hear they are

> going to do so soon.

> My mount is only a year old and the grease looks good and it is still

> clean. I will wait until next year and look again.

> I have heard the the Mobil Synthetic grease is suppose to be quite

> good and readily available at most good parts stores.

> Floyd

>



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

#38455 Jul 23, 2008

Tom,

I look forward to seeing the results of that.

Floyd --- In Losmandy_users@yahoogroups.com, Tomrigel Tomrigel@...> wrote:

>

> Hi Kev,

>

> Take a look at this guy's PE - less than 5 seconds - with no PEC and

no guiding. Hopefully, someday soon I'll generate this info on John's

G-11 and see how good the mount is.

>

> Tom

>

>

>

> In a message dated 07/23/08 12:51:51 Pacific Daylight Time,

fblue@... writes:

> Well, I have been working for two nights trying to get a log of my PE

> on the G-11 Gemini. Many problems due to conditions and inability to

> see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a little

> in PHD and then had PEAS decipher it and put PE into arc seconds based

> on pixel size and focal length.

> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.

> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

> Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>

>

>

>

>

> [Non-text portions of this message have been removed]

>



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

#38458 Jul 23, 2008

Probably in September when I get back. It will be the first time with the new mount.



Tom







In a message dated 07/23/08 15:47:54 Pacific Daylight Time, fblue@... writes:

Tom,

I look forward to seeing the results of that.

Floyd --- In Losmandy_users@yahoogroups.com, Tomrigel Tomrigel@...> wrote:

>

> Hi Kev,

>

> Take a look at this guy's PE - less than 5 seconds - with no PEC and

no guiding. Hopefully, someday soon I'll generate this info on John's

G-11 and see how good the mount is.

>

> Tom

>

>

>

> In a message dated 07/23/08 12:51:51 Pacific Daylight Time,

fblue@... writes:

> Well, I have been working for two nights trying to get a log of my PE

> on the G-11 Gemini. Many problems due to conditions and inability to

> see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a little

> in PHD and then had PEAS decipher it and put PE into arc seconds based

> on pixel size and focal length.

> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.

> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

> Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>

>

>

>

>

> [Non-text portions of this message have been removed]

>











[Non-text portions of this message have been removed]







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

#38464 Jul 23, 2008

Hi Floyd,

> The only problem with PemPro is that you must have CCDSoft or MaximDL

> to use it from what I understand. I use Nebulosity and Envisage with

> my DSI III Pro. The cost of Maxim is more than I wish to spend and



Just a FYI but PEMPro Build 47 and later *natively* supports all DSI models,

including the DSI III so you no longer need Maxim or AstroArt with DSI

cameras. I purchased 4 different DSI cameras (DSI, DSI Pro, DSI II PRo, and

DSI III Pro) and did a lot of testing with each of them.



You can find detailed instructions on using the DSI cameras natively with

PEMPro in the help file or online here:



www.siriusimaging.com/Help/PEMProV2/meadedsi.htm



-Ray Gralak

Author of PEMPro



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

#38465 Jul 23, 2008

AP only certifies to 7 arc seconds peak to peak, so I'd say you're

doing better than AP. But the 900 does have more load capacity. greg n

--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

>

> Thanks Rosario,

> I was pleased and rather amazed at how well this stock mount works.

> Certainly not an AP900, but it is very acceptable for the cost.

> Floyd

> --- In Losmandy_users@yahoogroups.com, "Rosario" rosario.pomillo@>

> wrote:

> >

> > Wow Floyd!

> > It seems excellent.

> > Rosario

> > www.astromaster.org

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

> > From: Floyd Blue

> > To: Losmandy_users@yahoogroups.com

> > Sent: Wednesday, July 23, 2008 9:51 PM

> > Subject: [Losmandy_users] 1 complete worm period, no PEC or

> guiding, G-11 Gemini

> >

> >

> > Well, I have been working for two nights trying to get a log of

my PE

> > on the G-11 Gemini. Many problems due to conditions and inability to

> > see east or west to get a good alignment and polar alignment in the

> > back yard.

> > However, after working on the polar alignment for one night and then

> > taking a log on the second, I got a complete worm cycle plus a

little

> > in PHD and then had PEAS decipher it and put PE into arc seconds

based

> > on pixel size and focal length.

> > The PEC was off and the guiding was turned off as well. I was only

> > able to get one worm period at a time without too much drift, so I

> > decided this would have to do.

> > This link to my photos shows the graph, which to my amazement, looks

> > like 4"-5" peak to peak with a fairly smooth wave.

> > Now I am not sure whether to even consider the Ovision worm block!

> >

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

> > Then I decided to take a 6 minute unguided image to see what it was

> > like. It had round stars and no trails, though the picture really

> > sucked due to light pollution, over exposure and the camera being at

> > 30.c because the cooling was not on due to dew point being high and

> > having it dew up the night before when I tried to cool to 10.c. :^)

> > Not sure what to make of the data, but it is the best that I can

> > muster without spending a bit on software to get Pempro to work.

> > Floyd

> >

> >

> >

> >

> >

> > [Non-text portions of this message have been removed]

> >

>



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

#38466 Jul 23, 2008

Thanks Ray, I did not realize that! That is good news, maybe I can

again download the 30 day trial and give it another go.

Floyd --- In Losmandy_users@yahoogroups.com, "Ray Gralak" rgr@...> wrote:

>

> Hi Floyd,

>

> > The only problem with PemPro is that you must have CCDSoft or MaximDL

> > to use it from what I understand. I use Nebulosity and Envisage with

> > my DSI III Pro. The cost of Maxim is more than I wish to spend and

>

> Just a FYI but PEMPro Build 47 and later *natively* supports all DSI

models,

> including the DSI III so you no longer need Maxim or AstroArt with DSI

> cameras. I purchased 4 different DSI cameras (DSI, DSI Pro, DSI II

PRo, and

> DSI III Pro) and did a lot of testing with each of them.

>

> You can find detailed instructions on using the DSI cameras natively

with

> PEMPro in the help file or online here:

>

> www.siriusimaging.com/Help/PEMProV2/meadedsi.htm

>

> -Ray Gralak

> Author of PEMPro

>



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

#38467 Jul 23, 2008

Hi Greg,

Well the AP will have a smoother wave too as well as more capacity. I

wish I could afford an AP900 but the cost is just above my budget.

Roland makes some really fine gear, there is nothing that he makes

that I would not love to own.

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> AP only certifies to 7 arc seconds peak to peak, so I'd say you're

> doing better than AP. But the 900 does have more load capacity. greg n

>

> --- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@> wrote:

> >

> > Thanks Rosario,

> > I was pleased and rather amazed at how well this stock mount works.

> > Certainly not an AP900, but it is very acceptable for the cost.

> > Floyd

> > --- In Losmandy_users@yahoogroups.com, "Rosario" rosario.pomillo@>

> > wrote:

> > >

> > > Wow Floyd!

> > > It seems excellent.

> > > Rosario

> > > www.astromaster.org

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

> > > From: Floyd Blue

> > > To: Losmandy_users@yahoogroups.com

> > > Sent: Wednesday, July 23, 2008 9:51 PM

> > > Subject: [Losmandy_users] 1 complete worm period, no PEC or

> > guiding, G-11 Gemini

> > >

> > >

> > > Well, I have been working for two nights trying to get a log of

> my PE

> > > on the G-11 Gemini. Many problems due to conditions and

inability to

> > > see east or west to get a good alignment and polar alignment

in the

> > > back yard.

> > > However, after working on the polar alignment for one night

and then

> > > taking a log on the second, I got a complete worm cycle plus a

> little

> > > in PHD and then had PEAS decipher it and put PE into arc seconds

> based

> > > on pixel size and focal length.

> > > The PEC was off and the guiding was turned off as well. I was only

> > > able to get one worm period at a time without too much drift, so I

> > > decided this would have to do.

> > > This link to my photos shows the graph, which to my amazement,

looks

> > > like 4"-5" peak to peak with a fairly smooth wave.

> > > Now I am not sure whether to even consider the Ovision worm block!

> > >

> >

>

tech.ph.groups.yahoo.com/group/Losmandy_users/photos/view/92a9?b=13

> > > Then I decided to take a 6 minute unguided image to see what

it was

> > > like. It had round stars and no trails, though the picture really

> > > sucked due to light pollution, over exposure and the camera

being at

> > > 30.c because the cooling was not on due to dew point being

high and

> > > having it dew up the night before when I tried to cool to

10.c. :^)

> > > Not sure what to make of the data, but it is the best that I can

> > > muster without spending a bit on software to get Pempro to work.

> > > Floyd

> > >

> > >

> > >

> > >

> > >

> > > [Non-text portions of this message have been removed]

> > >

> >

>







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

#38468 Jul 23, 2008

Hi Floyd,



The very odd thing about your graph is that it looks like there is virtually

no periodic nature to it at all - just some random movements, perhaps like

would be seen from worm wheel tooth imperfections.



Also, it is very important to make sure the camera is not rotated and that

you have selected the correct axis (RA not Dec). If the axis is rotated,

even a bit, then the RA measurement will be subdued. Lastly, you want to

make sure the image scale is correct (don't rely on manufacturer's focal

length claims) and that you measure PEC of a star very close to 0

declination. If you use a star not at 0 dec you have to divide the periodic

error by the cosine of the declination, which makes actual PE bigger than

what is measured.



BTW, would you mind uploading your PHD log file to the files section? I am

adding the ability to read PHD log files to PEMPro and I am looking for

random log files to test.



Thanks,



-Ray

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

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com] On Behalf Of Floyd Blue

> Sent: Wednesday, July 23, 2008 12:52 PM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] 1 complete worm period, no PEC or

> guiding, G-11 Gemini

>

> Well, I have been working for two nights trying to get a log of my PE

> on the G-11 Gemini. Many problems due to conditions and inability to

> see east or west to get a good alignment and polar alignment in the

> back yard.

> However, after working on the polar alignment for one night and then

> taking a log on the second, I got a complete worm cycle plus a little

> in PHD and then had PEAS decipher it and put PE into arc seconds based

> on pixel size and focal length.

> The PEC was off and the guiding was turned off as well. I was only

> able to get one worm period at a time without too much drift, so I

> decided this would have to do.

> This link to my photos shows the graph, which to my amazement, looks

> like 4"-5" peak to peak with a fairly smooth wave.

> Now I am not sure whether to even consider the Ovision worm block!

> tech.ph.groups.yahoo.com/group/Losmandy_users/photos/vi

> ew/92a9?b=13

> tech.ph.groups.yahoo.com/group/Losmandy_users/photos/v

> iew/92a9?b=13>

> Then I decided to take a 6 minute unguided image to see what it was

> like. It had round stars and no trails, though the picture really

> sucked due to light pollution, over exposure and the camera being at

> 30.c because the cooling was not on due to dew point being high and

> having it dew up the night before when I tried to cool to 10.c. :^)

> Not sure what to make of the data, but it is the best that I can

> muster without spending a bit on software to get Pempro to work.

> Floyd

>

>

>

>

>



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

#38470 Jul 23, 2008

Glad you raised the issue of PE specs, Greg. In particular, Astro-

Physics is one of a very few (maybe the only?) mount suppliers that

*guaranties* a maximum PE. The value of 7 arc seconds applies to the

Mach1GTO; the AP1200GTO has a 5 arc second limit. I could tell you

what Roland measured on my mount before he shipped it, but that would

just be bragging.



What do other suppliers have in the way of PE specs?

Meade . none whatsoever; PEs of 120 arc seconds for LX200GPS scopes

(on wedges) have been reported by reputable imagers

Celestron . none whatsoever

Losmandy . none whatsoever

Mountain Instruments . now here we see some interesting, I'd call

them amusing, specs. I quote from

www.mountaininstruments.com/pages/mi250Go-To.html

"Perridoc (sic) error is very low and smooth. Average 3-5 arc sec."



Now one doesn't need a PhD in Math to note that average is a single-

valued function, and not a range of values. But more to the point,

an "average PE" is no guide to what you will actually get when you

open the box and test the mount. Indeed, what if the mount you get is

in fact several standard deviations removed from the average value?

In other words, an outlier with a PE of, say, 80 arc seconds. Is the

80 arc second PE out of "spec". Legally, no.



It bothers me that mount manufacturers (except perhaps A-P) do not

adequately specify their products so that the purchaser knows up

front what they can expect from a worst-case perspective. We're just

rolling the dice.



Soapbox dismounted.



Clear skies,



Dennis Persyk

Igloo Observatory Home Page dpersyk.home.att.net

Hampshire, IL

Pier Design home.att.net/~dpersyk/Pier_Design.htm



--- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...>

wrote: >

> AP only certifies to 7 arc seconds peak to peak, so I'd say you're

> doing better than AP. But the 900 does have more load capacity.

greg n >



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

#38472 Jul 23, 2008

Hi Ray,

Yes, I noticed that as well, no real periodic wave patterns. Not sure

what to make of that.

I did calibrate with PHD first so that it would know N_S_E_W and then

stopped the guiding, disabled the guiding in the brain and then

started the guiding, centered the star manually and then started the log.

Is this not the right way to do it? I thought that it would be right.



Floyd --- In Losmandy_users@yahoogroups.com, "Ray Gralak" rgr@...> wrote:

>

> Hi Floyd,

>

> The very odd thing about your graph is that it looks like there is

virtually

> no periodic nature to it at all - just some random movements,

perhaps like

> would be seen from worm wheel tooth imperfections.

>

> Also, it is very important to make sure the camera is not rotated

and that

> you have selected the correct axis (RA not Dec). If the axis is rotated,

> even a bit, then the RA measurement will be subdued. Lastly, you want to

> make sure the image scale is correct (don't rely on manufacturer's focal

> length claims) and that you measure PEC of a star very close to 0

> declination. If you use a star not at 0 dec you have to divide the

periodic

> error by the cosine of the declination, which makes actual PE bigger

than

> what is measured.

>

> BTW, would you mind uploading your PHD log file to the files

section? I am

> adding the ability to read PHD log files to PEMPro and I am looking for

> random log files to test.

>

> Thanks,

>

> -Ray

>

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

> > From: Losmandy_users@yahoogroups.com

> > [mailto:Losmandy_users@yahoogroups.com] On Behalf Of Floyd Blue

> > Sent: Wednesday, July 23, 2008 12:52 PM

> > To: Losmandy_users@yahoogroups.com

> > Subject: [Losmandy_users] 1 complete worm period, no PEC or

> > guiding, G-11 Gemini

> >

> > Well, I have been working for two nights trying to get a log of my PE

> > on the G-11 Gemini. Many problems due to conditions and inability to

> > see east or west to get a good alignment and polar alignment in the

> > back yard.

> > However, after working on the polar alignment for one night and then

> > taking a log on the second, I got a complete worm cycle plus a little

> > in PHD and then had PEAS decipher it and put PE into arc seconds based

> > on pixel size and focal length.

> > The PEC was off and the guiding was turned off as well. I was only

> > able to get one worm period at a time without too much drift, so I

> > decided this would have to do.

> > This link to my photos shows the graph, which to my amazement, looks

> > like 4"-5" peak to peak with a fairly smooth wave.

> > Now I am not sure whether to even consider the Ovision worm block!

> > tech.ph.groups.yahoo.com/group/Losmandy_users/photos/vi

> > ew/92a9?b=13

> > tech.ph.groups.yahoo.com/group/Losmandy_users/photos/v

> > iew/92a9?b=13>

> > Then I decided to take a 6 minute unguided image to see what it was

> > like. It had round stars and no trails, though the picture really

> > sucked due to light pollution, over exposure and the camera being at

> > 30.c because the cooling was not on due to dew point being high and

> > having it dew up the night before when I tried to cool to 10.c. :^)

> > Not sure what to make of the data, but it is the best that I can

> > muster without spending a bit on software to get Pempro to work.

> > Floyd

> >

> >

> >

> >

> >

>







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

#38473 Jul 23, 2008

Hi Ray,

Yes, I believe the Pempro was installed on this laptop, it has been a

while. This is one of the reasons that I have not tried again, I

thought it would only work once.

I really hate to spend $150 on a program that I may not actually need.

Floyd --- In Losmandy_users@yahoogroups.com, "Ray Gralak" rgr@...> wrote:

>

> Hi Floyd,

>

> If you already installed PEMPro on your PC and the 60-day trial has

expired

> you may not be able to run the current version. If so, you could

either try

> PEMPro on another PC or wait until I add a scheme to extend the trial.

>

> -Ray

>

> > Thanks Ray, I did not realize that! That is good news, maybe I can

> > again download the 30 day trial and give it another go.

> > Floyd

> > --- In Losmandy_users@yahoogroups.com

> > mailto:Losmandy_users%40yahoogroups.com> , "Ray Gralak"

> > rgr@> wrote:

> > >

> > > Hi Floyd,

> > >

> > > > The only problem with PemPro is that you must have

> > CCDSoft or MaximDL

> > > > to use it from what I understand. I use Nebulosity and

> > Envisage with

> > > > my DSI III Pro. The cost of Maxim is more than I wish to spend and

> > >

> > > Just a FYI but PEMPro Build 47 and later *natively* supports all DSI

> > models,

> > > including the DSI III so you no longer need Maxim or

> > AstroArt with DSI

> > > cameras. I purchased 4 different DSI cameras (DSI, DSI Pro, DSI II

> > PRo, and

> > > DSI III Pro) and did a lot of testing with each of them.

> > >

> > > You can find detailed instructions on using the DSI cameras natively

> > with

> > > PEMPro in the help file or online here:

> > >

> > > www.siriusimaging.com/Help/PEMProV2/meadedsi.htm

> > www.siriusimaging.com/Help/PEMProV2/meadedsi.htm>

> > >

> > > -Ray Gralak

> > > Author of PEMPro

> > >

> >

> >

> >

> >

> >

>



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

#38475 Jul 24, 2008

Ray Gralak wrote: > The very odd thing about your graph is that it looks like there is virtually

> no periodic nature to it at all - just some random movements, perhaps like

> would be seen from worm wheel tooth imperfections.



Thanks, Ray. I was going to comment on this myself, but other things got

in the way. Not only are there a bunch of little humps and dips,there is

no indication of a single sine wave over the entire period, which I

would expect for one complete worm cycle. Especially puzzling is the

hump with the steep trailing edge near the center of the graph. MAYBE

and there is an abnormal tooth on the RA worm gear, but to me this looks

like the declination axis flopping back and forth.



Mike

-----



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com



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

#38481 Jul 24, 2008

Hi Mike,

The DEC could have been flopping a little, it was less than perfect on

the polar alignment and I did see some DEC drift.

Not sure why there was no periodic error, perhaps my methods did not

really produce a good graph?

Too much time spent on this, so I think I am not going to waste anothe

night at it. The truth is, a 6 minute unguided sub showed no out of

round stars, so that is good enough for the demands I put on my mount.

:^)

Maybe one day I will buy the Pempro and could do a better job of this.

This was my first attempt at getting a PE graph, so mark it up to

inexperience.

Floyd

--- In Losmandy_users@yahoogroups.com, Mike Dodd mike@...> wrote:

>

> Ray Gralak wrote:

> > The very odd thing about your graph is that it looks like there is

virtually

> > no periodic nature to it at all - just some random movements,

perhaps like

> > would be seen from worm wheel tooth imperfections.

>

> Thanks, Ray. I was going to comment on this myself, but other things

got

> in the way. Not only are there a bunch of little humps and

dips,there is

> no indication of a single sine wave over the entire period, which I

> would expect for one complete worm cycle. Especially puzzling is the

> hump with the steep trailing edge near the center of the graph. MAYBE

> and there is an abnormal tooth on the RA worm gear, but to me this

looks

> like the declination axis flopping back and forth.

>

> Mike

> -----

>

> Mike Dodd

> Montpelier, VA USA

> astronomy.mdodd.com

>



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

#38484 Jul 24, 2008

Paramount ME guarantees the PE.

Ovision guarantees its PE! So there you have something.



Your main point however is one of the thigns that bothers me about the

good results we've been seeing with the brass worms: I don't know what

% of cases it represents, and how replicable it is. Floyd may say it

is easy to use a feeler gauge with the worm setup and that may be

true. I had oodles of advice about using the feeler gauge when I

owned a titan. And I had at least four feeler gauges which I used both

in the field and in garage tests.



I got pretty tired of that pretty fast. No feeler gauge is required

for the Ovision, which is territory I'm comfortable with. I don't use

one with my AP900 either. Never tested the PE on that.



regards

Greg N





--- In Losmandy_users@yahoogroups.com, "Dennis Persyk" dpersyk@...>

wrote: >

> Glad you raised the issue of PE specs, Greg. In particular, Astro-

> Physics is one of a very few (maybe the only?) mount suppliers that

> *guaranties* a maximum PE. The value of 7 arc seconds applies to the

> Mach1GTO; the AP1200GTO has a 5 arc second limit. I could tell you

> what Roland measured on my mount before he shipped it, but that would

> just be bragging.

>

> What do other suppliers have in the way of PE specs?

> Meade . none whatsoever; PEs of 120 arc seconds for LX200GPS scopes

> (on wedges) have been reported by reputable imagers

> Celestron . none whatsoever

> Losmandy . none whatsoever

> Mountain Instruments . now here we see some interesting, I'd call

> them amusing, specs. I quote from

> www.mountaininstruments.com/pages/mi250Go-To.html

> "Perridoc (sic) error is very low and smooth. Average 3-5 arc sec."

>

> Now one doesn't need a PhD in Math to note that average is a single-

> valued function, and not a range of values. But more to the point,

> an "average PE" is no guide to what you will actually get when you

> open the box and test the mount. Indeed, what if the mount you get is

> in fact several standard deviations removed from the average value?

> In other words, an outlier with a PE of, say, 80 arc seconds. Is the

> 80 arc second PE out of "spec". Legally, no.

>

> It bothers me that mount manufacturers (except perhaps A-P) do not

> adequately specify their products so that the purchaser knows up

> front what they can expect from a worst-case perspective. We're just

> rolling the dice.

>

> Soapbox dismounted.

>

> Clear skies,

>

> Dennis Persyk

> Igloo Observatory Home Page dpersyk.home.att.net

> Hampshire, IL

> Pier Design home.att.net/~dpersyk/Pier_Design.htm

>

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> wrote:

> >

> > AP only certifies to 7 arc seconds peak to peak, so I'd say you're

> > doing better than AP. But the 900 does have more load capacity.

> greg n

> >

>







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

#38485 Jul 24, 2008

Greg,



Titan has a similar type of singe-block worm assembly as the one

from Ovision. Don't know what the issue was with your Titan, but

there's as much need to use feeler gauges with a Titan as there is

with Ovision.



Actually, there's even less of a need for it with a Titan because

the motor is attached to, and moves with the worm assembly. So it

can't move, and it's never askew, while the Oldham coupler in the

Ovision assembly makes motor shaft misalignment possible.



BTW, Losmandy does specify Titan PE at a maximum +/-5 arcseconds.



Regards,



-Paul





--- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...>

wrote: >

> Paramount ME guarantees the PE.

> Ovision guarantees its PE! So there you have something.

>

> Your main point however is one of the thigns that bothers me about

the > good results we've been seeing with the brass worms: I don't know

what > % of cases it represents, and how replicable it is. Floyd may say

it > is easy to use a feeler gauge with the worm setup and that may be

> true. I had oodles of advice about using the feeler gauge when I

> owned a titan. And I had at least four feeler gauges which I used

both > in the field and in garage tests.

>

> I got pretty tired of that pretty fast. No feeler gauge is

required > for the Ovision, which is territory I'm comfortable with. I don't

use > one with my AP900 either. Never tested the PE on that.

>

> regards

> Greg N



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

#38487 Jul 24, 2008

Hi Greg,

What do you use to set the Ovision if you do not use a feeler gauge?

Do you just use the feel method of grabbing it and seeing how much it

moves and then move the block or what?

I use the feeler gauges by setting the lash to tight, then add .001"

or more to the gap until it feels about right. The gauges just give me

control over the changes I make, so that I don't just guesstimate over

and over, until maybe I get it right. I guess that just comes from

being a mechanic for over 30 years. :^)

Just wondering?

By the way, I do not feel that my testing can be considered the

absolute proof of anything. I may or may not have done this right, so

I think I will just back out of this at this time. Seems like the

demands for perfection in testing are probably beyond what I want to

get involved with, after all I am just trying to take photographs, not

get an engineering degree. (Grin)

;^)

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> Paramount ME guarantees the PE.

> Ovision guarantees its PE! So there you have something.

>

> Your main point however is one of the thigns that bothers me about the

> good results we've been seeing with the brass worms: I don't know what

> % of cases it represents, and how replicable it is. Floyd may say it

> is easy to use a feeler gauge with the worm setup and that may be

> true. I had oodles of advice about using the feeler gauge when I

> owned a titan. And I had at least four feeler gauges which I used both

> in the field and in garage tests.

>

> I got pretty tired of that pretty fast. No feeler gauge is required

> for the Ovision, which is territory I'm comfortable with. I don't use

> one with my AP900 either. Never tested the PE on that.

>

> regards

> Greg N

>

>

> --- In Losmandy_users@yahoogroups.com, "Dennis Persyk" dpersyk@>

> wrote:

> >

> > Glad you raised the issue of PE specs, Greg. In particular, Astro-

> > Physics is one of a very few (maybe the only?) mount suppliers that

> > *guaranties* a maximum PE. The value of 7 arc seconds applies to the

> > Mach1GTO; the AP1200GTO has a 5 arc second limit. I could tell you

> > what Roland measured on my mount before he shipped it, but that would

> > just be bragging.

> >

> > What do other suppliers have in the way of PE specs?

> > Meade . none whatsoever; PEs of 120 arc seconds for LX200GPS scopes

> > (on wedges) have been reported by reputable imagers

> > Celestron . none whatsoever

> > Losmandy . none whatsoever

> > Mountain Instruments . now here we see some interesting, I'd call

> > them amusing, specs. I quote from

> > www.mountaininstruments.com/pages/mi250Go-To.html

> > "Perridoc (sic) error is very low and smooth. Average 3-5 arc sec."

> >

> > Now one doesn't need a PhD in Math to note that average is a single-

> > valued function, and not a range of values. But more to the point,

> > an "average PE" is no guide to what you will actually get when you

> > open the box and test the mount. Indeed, what if the mount you get is

> > in fact several standard deviations removed from the average value?

> > In other words, an outlier with a PE of, say, 80 arc seconds. Is the

> > 80 arc second PE out of "spec". Legally, no.

> >

> > It bothers me that mount manufacturers (except perhaps A-P) do not

> > adequately specify their products so that the purchaser knows up

> > front what they can expect from a worst-case perspective. We're just

> > rolling the dice.

> >

> > Soapbox dismounted.

> >

> > Clear skies,

> >

> > Dennis Persyk

> > Igloo Observatory Home Page dpersyk.home.att.net

> > Hampshire, IL

> > Pier Design home.att.net/~dpersyk/Pier_Design.htm

> >

> > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> > wrote:

> > >

> > > AP only certifies to 7 arc seconds peak to peak, so I'd say you're

> > > doing better than AP. But the 900 does have more load capacity.

> > greg n

> > >

> >

>







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

#38488 Jul 24, 2008

An engineering degree is much, much easier :)



-Paul

--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

> after all I am just trying to take photographs, not

> get an engineering degree. (Grin)



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

#38489 Jul 24, 2008

Franck's directions suggested 1mm of play as measured at the *very

end* of the counterweight shaft. There was about 3x to 4x that much

when I did the test that you see posted on astromart. Now I've cut it

down. (I had originally understood the directions to mean 1mm *at the

gear*).



This block is so easy to adjust that if the play bothers me in the

field I would have no problem pulling out an Allen wrench and snugging

it up.



Personally I think I've had it with separate bearing blocks. I'm

really glad not to be there any more. I'll keep the ones I have in

case some extremity requires me to change. I'm still mulling over

what to do about Dec. There's no point in Ovision for Dec but it

might be no point in the Martin block either. Right now Dec works

fine and I'm inclined to leave it. But I *do* have a brass worm here

that I haven't installed; when the impulse to fuss with the mount

comes, that's probably what will happen.



regards

Greg N





--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

>

> Hi Greg,

> What do you use to set the Ovision if you do not use a feeler gauge?

> Do you just use the feel method of grabbing it and seeing how much it

> moves and then move the block or what?

> I use the feeler gauges by setting the lash to tight, then add .001"

> or more to the gap until it feels about right. The gauges just give me

> control over the changes I make, so that I don't just guesstimate over

> and over, until maybe I get it right. I guess that just comes from

> being a mechanic for over 30 years. :^)

> Just wondering?

> By the way, I do not feel that my testing can be considered the

> absolute proof of anything. I may or may not have done this right, so

> I think I will just back out of this at this time. Seems like the

> demands for perfection in testing are probably beyond what I want to

> get involved with, after all I am just trying to take photographs, not

> get an engineering degree. (Grin)

> ;^)

> Floyd

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@> wrote:

> >

> > Paramount ME guarantees the PE.

> > Ovision guarantees its PE! So there you have something.

> >

> > Your main point however is one of the thigns that bothers me about the

> > good results we've been seeing with the brass worms: I don't know what

> > % of cases it represents, and how replicable it is. Floyd may say it

> > is easy to use a feeler gauge with the worm setup and that may be

> > true. I had oodles of advice about using the feeler gauge when I

> > owned a titan. And I had at least four feeler gauges which I used both

> > in the field and in garage tests.

> >

> > I got pretty tired of that pretty fast. No feeler gauge is required

> > for the Ovision, which is territory I'm comfortable with. I don't use

> > one with my AP900 either. Never tested the PE on that.

> >

> > regards

> > Greg N

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Dennis Persyk" dpersyk@>

> > wrote:

> > >

> > > Glad you raised the issue of PE specs, Greg. In particular, Astro-

> > > Physics is one of a very few (maybe the only?) mount suppliers that

> > > *guaranties* a maximum PE. The value of 7 arc seconds applies to

the

> > > Mach1GTO; the AP1200GTO has a 5 arc second limit. I could tell you

> > > what Roland measured on my mount before he shipped it, but that

would

> > > just be bragging.

> > >

> > > What do other suppliers have in the way of PE specs?

> > > Meade . none whatsoever; PEs of 120 arc seconds for LX200GPS scopes

> > > (on wedges) have been reported by reputable imagers

> > > Celestron . none whatsoever

> > > Losmandy . none whatsoever

> > > Mountain Instruments . now here we see some interesting, I'd call

> > > them amusing, specs. I quote from

> > > www.mountaininstruments.com/pages/mi250Go-To.html

> > > "Perridoc (sic) error is very low and smooth. Average 3-5 arc sec."

> > >

> > > Now one doesn't need a PhD in Math to note that average is a single-

> > > valued function, and not a range of values. But more to the

point,

> > > an "average PE" is no guide to what you will actually get when you

> > > open the box and test the mount. Indeed, what if the mount you

get is

> > > in fact several standard deviations removed from the average value?

> > > In other words, an outlier with a PE of, say, 80 arc seconds.

Is the

> > > 80 arc second PE out of "spec". Legally, no.

> > >

> > > It bothers me that mount manufacturers (except perhaps A-P) do not

> > > adequately specify their products so that the purchaser knows up

> > > front what they can expect from a worst-case perspective. We're

just

> > > rolling the dice.

> > >

> > > Soapbox dismounted.

> > >

> > > Clear skies,

> > >

> > > Dennis Persyk

> > > Igloo Observatory Home Page dpersyk.home.att.net

> > > Hampshire, IL

> > > Pier Design home.att.net/~dpersyk/Pier_Design.htm

> > >

> > > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> > > wrote:

> > > >

> > > > AP only certifies to 7 arc seconds peak to peak, so I'd say you're

> > > > doing better than AP. But the 900 does have more load capacity.

> > > greg n

> > > >

> > >

> >

>







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

#38490 Jul 24, 2008

I see your point about the block. Something about that Titan and me

just did not click. It was a tremendous disappointment given the work

I've put into this group. I was tremendously committed do doing an

upgrade within the Losmandy line.



The G11 however has been a real winner for me and I'm glad I had the

sense not to sell it when I got the AP900QMD.



In any case y'all seen the results I got with a lewd and crude Ovision

installation. So as far as I am concerned it has the virtue of being

idiot proof (me-proof). One of the factors that we cannot eliminate

from some discussions is how much production variance enters into

different experiences with equipment; also, some users are just better

suited for sweet-talking some pieces of metal into doing what they should.



Interestingly, the issues that I had to deal with on the AP900QMD were

quite intense and at least in theory much more difficult mechanically

than the Titan adjustments. I had to get the counterweight shaft

machined down a bit. I had to deal with a rather complicated encoder

situation where the OEM encoder design was defective. But for these

issues I found solutions.



I've also done OK with two different SP mounts. The Titan was the

first mount that defeated me.



regards

Greg N

--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@...> wrote:

>

> Greg,

>

> Titan has a similar type of singe-block worm assembly as the one

> from Ovision. Don't know what the issue was with your Titan, but

> there's as much need to use feeler gauges with a Titan as there is

> with Ovision.

>

> Actually, there's even less of a need for it with a Titan because

> the motor is attached to, and moves with the worm assembly. So it

> can't move, and it's never askew, while the Oldham coupler in the

> Ovision assembly makes motor shaft misalignment possible.

>

> BTW, Losmandy does specify Titan PE at a maximum +/-5 arcseconds.

>

> Regards,

>

> -Paul

>

>

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> wrote:

> >

> > Paramount ME guarantees the PE.

> > Ovision guarantees its PE! So there you have something.

> >

> > Your main point however is one of the thigns that bothers me about

> the

> > good results we've been seeing with the brass worms: I don't know

> what

> > % of cases it represents, and how replicable it is. Floyd may say

> it

> > is easy to use a feeler gauge with the worm setup and that may be

> > true. I had oodles of advice about using the feeler gauge when I

> > owned a titan. And I had at least four feeler gauges which I used

> both

> > in the field and in garage tests.

> >

> > I got pretty tired of that pretty fast. No feeler gauge is

> required

> > for the Ovision, which is territory I'm comfortable with. I don't

> use

> > one with my AP900 either. Never tested the PE on that.

> >

> > regards

> > Greg N

>



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

#38491 Jul 24, 2008

Hi Greg,

That sounds quite easy all right.

Not sure I would go to the expense of either option for the DEC, not

really needed I think.

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> Franck's directions suggested 1mm of play as measured at the *very

> end* of the counterweight shaft. There was about 3x to 4x that much

> when I did the test that you see posted on astromart. Now I've cut it

> down. (I had originally understood the directions to mean 1mm *at the

> gear*).

>

> This block is so easy to adjust that if the play bothers me in the

> field I would have no problem pulling out an Allen wrench and snugging

> it up.

>

> Personally I think I've had it with separate bearing blocks. I'm

> really glad not to be there any more. I'll keep the ones I have in

> case some extremity requires me to change. I'm still mulling over

> what to do about Dec. There's no point in Ovision for Dec but it

> might be no point in the Martin block either. Right now Dec works

> fine and I'm inclined to leave it. But I *do* have a brass worm here

> that I haven't installed; when the impulse to fuss with the mount

> comes, that's probably what will happen.

>

> regards

> Greg N

>

>

>

> --- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@> wrote:

> >

> > Hi Greg,

> > What do you use to set the Ovision if you do not use a feeler gauge?

> > Do you just use the feel method of grabbing it and seeing how much it

> > moves and then move the block or what?

> > I use the feeler gauges by setting the lash to tight, then add .001"

> > or more to the gap until it feels about right. The gauges just give me

> > control over the changes I make, so that I don't just guesstimate over

> > and over, until maybe I get it right. I guess that just comes from

> > being a mechanic for over 30 years. :^)

> > Just wondering?

> > By the way, I do not feel that my testing can be considered the

> > absolute proof of anything. I may or may not have done this right, so

> > I think I will just back out of this at this time. Seems like the

> > demands for perfection in testing are probably beyond what I want to

> > get involved with, after all I am just trying to take photographs, not

> > get an engineering degree. (Grin)

> > ;^)

> > Floyd

> > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@> wrote:

> > >

> > > Paramount ME guarantees the PE.

> > > Ovision guarantees its PE! So there you have something.

> > >

> > > Your main point however is one of the thigns that bothers me

about the

> > > good results we've been seeing with the brass worms: I don't

know what

> > > % of cases it represents, and how replicable it is. Floyd may

say it

> > > is easy to use a feeler gauge with the worm setup and that may be

> > > true. I had oodles of advice about using the feeler gauge when I

> > > owned a titan. And I had at least four feeler gauges which I

used both

> > > in the field and in garage tests.

> > >

> > > I got pretty tired of that pretty fast. No feeler gauge is required

> > > for the Ovision, which is territory I'm comfortable with. I

don't use

> > > one with my AP900 either. Never tested the PE on that.

> > >

> > > regards

> > > Greg N

> > >

> > >

> > > --- In Losmandy_users@yahoogroups.com, "Dennis Persyk" dpersyk@>

> > > wrote:

> > > >

> > > > Glad you raised the issue of PE specs, Greg. In particular,

Astro-

> > > > Physics is one of a very few (maybe the only?) mount suppliers

that

> > > > *guaranties* a maximum PE. The value of 7 arc seconds applies to

> the

> > > > Mach1GTO; the AP1200GTO has a 5 arc second limit. I could tell

you

> > > > what Roland measured on my mount before he shipped it, but that

> would

> > > > just be bragging.

> > > >

> > > > What do other suppliers have in the way of PE specs?

> > > > Meade . none whatsoever; PEs of 120 arc seconds for LX200GPS

scopes

> > > > (on wedges) have been reported by reputable imagers

> > > > Celestron . none whatsoever

> > > > Losmandy . none whatsoever

> > > > Mountain Instruments . now here we see some interesting, I'd call

> > > > them amusing, specs. I quote from

> > > > www.mountaininstruments.com/pages/mi250Go-To.html

> > > > "Perridoc (sic) error is very low and smooth. Average 3-5 arc

sec."

> > > >

> > > > Now one doesn't need a PhD in Math to note that average is a

single-

> > > > valued function, and not a range of values. But more to the

> point,

> > > > an "average PE" is no guide to what you will actually get when

you

> > > > open the box and test the mount. Indeed, what if the mount you

> get is

> > > > in fact several standard deviations removed from the average

value?

> > > > In other words, an outlier with a PE of, say, 80 arc seconds.

> Is the

> > > > 80 arc second PE out of "spec". Legally, no.

> > > >

> > > > It bothers me that mount manufacturers (except perhaps A-P) do

not

> > > > adequately specify their products so that the purchaser knows up

> > > > front what they can expect from a worst-case perspective. We're

> just

> > > > rolling the dice.

> > > >

> > > > Soapbox dismounted.

> > > >

> > > > Clear skies,

> > > >

> > > > Dennis Persyk

> > > > Igloo Observatory Home Page dpersyk.home.att.net

> > > > Hampshire, IL

> > > > Pier Design home.att.net/~dpersyk/Pier_Design.htm

> > > >

> > > > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> > > > wrote:

> > > > >

> > > > > AP only certifies to 7 arc seconds peak to peak, so I'd say

you're

> > > > > doing better than AP. But the 900 does have more load

capacity.

> > > > greg n

> > > > >

> > > >

> > >

> >

>







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

#38492 Jul 24, 2008

Wow, that sounds like a bit of work on the AP900! But I am sure it was

worth it in the end.

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> I see your point about the block. Something about that Titan and me

> just did not click. It was a tremendous disappointment given the work

> I've put into this group. I was tremendously committed do doing an

> upgrade within the Losmandy line.

>

> The G11 however has been a real winner for me and I'm glad I had the

> sense not to sell it when I got the AP900QMD.

>

> In any case y'all seen the results I got with a lewd and crude Ovision

> installation. So as far as I am concerned it has the virtue of being

> idiot proof (me-proof). One of the factors that we cannot eliminate

> from some discussions is how much production variance enters into

> different experiences with equipment; also, some users are just better

> suited for sweet-talking some pieces of metal into doing what they

should.

>

> Interestingly, the issues that I had to deal with on the AP900QMD were

> quite intense and at least in theory much more difficult mechanically

> than the Titan adjustments. I had to get the counterweight shaft

> machined down a bit. I had to deal with a rather complicated encoder

> situation where the OEM encoder design was defective. But for these

> issues I found solutions.

>

> I've also done OK with two different SP mounts. The Titan was the

> first mount that defeated me.

>

> regards

> Greg N

>

> --- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@> wrote:

> >

> > Greg,

> >

> > Titan has a similar type of singe-block worm assembly as the one

> > from Ovision. Don't know what the issue was with your Titan, but

> > there's as much need to use feeler gauges with a Titan as there is

> > with Ovision.

> >

> > Actually, there's even less of a need for it with a Titan because

> > the motor is attached to, and moves with the worm assembly. So it

> > can't move, and it's never askew, while the Oldham coupler in the

> > Ovision assembly makes motor shaft misalignment possible.

> >

> > BTW, Losmandy does specify Titan PE at a maximum +/-5 arcseconds.

> >

> > Regards,

> >

> > -Paul

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> > wrote:

> > >

> > > Paramount ME guarantees the PE.

> > > Ovision guarantees its PE! So there you have something.

> > >

> > > Your main point however is one of the thigns that bothers me about

> > the

> > > good results we've been seeing with the brass worms: I don't know

> > what

> > > % of cases it represents, and how replicable it is. Floyd may say

> > it

> > > is easy to use a feeler gauge with the worm setup and that may be

> > > true. I had oodles of advice about using the feeler gauge when I

> > > owned a titan. And I had at least four feeler gauges which I used

> > both

> > > in the field and in garage tests.

> > >

> > > I got pretty tired of that pretty fast. No feeler gauge is

> > required

> > > for the Ovision, which is territory I'm comfortable with. I don't

> > use

> > > one with my AP900 either. Never tested the PE on that.

> > >

> > > regards

> > > Greg N

> >

>



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

#38494 Jul 25, 2008

--- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...>

wrote: > The Titan was the first mount that defeated me.



Oh, The Mighty Titan! :)



I really couldn't understand why you had all the issues with it, and

felt bad that you had to go through it. Seems that particular mount

just liked the warmer climate :)



Mine has been fully operational for three years now, with no

adjustments after the first winter. It's been sitting outside all

this time, in 10F to 100F degree weather, rain, snow, etc. It's

covered up by a tarp, but that's all the protection it has from the

elements (and the fauna).



The biggest issue I've had to deal with was a large bee hive on the

pier, under the tarp. Thankfully, they didn't decide to build the

hive in the worm/gear area! :-)



Regards,



-Paul



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

#38500 Jul 25, 2008

Well AP has the reputation for doing everythign right. And it's real

nice stuff. Real nice.



But let me tell you this: the AP dsc design is *incredibly* inferior

to the one Scott designed and still sells. It looks better, but it is

fatally flawed unless modified. Details and all are in the Argo Navis

Yahoo! FILES section; but I think I may have put a photo essay in

PHOTOS. So check both if interested.



regards

Greg N



--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

>

> Wow, that sounds like a bit of work on the AP900! But I am sure it was

> worth it in the end.

> Floyd

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@> wrote:

> >

> > I see your point about the block. Something about that Titan and me

> > just did not click. It was a tremendous disappointment given the work

> > I've put into this group. I was tremendously committed do doing an

> > upgrade within the Losmandy line.

>

> > > > regards

> > > > Greg N

> > >

> >

>







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

#38501 Jul 25, 2008

Yeah and I lost somewhere between $1500 and $2k on it too, for what

with various costs to have it shipped, "repaired" (repairs did

nothing), and marking it down to sell at a loss (I bought used, but

sold at a lower price than I bought).



It was a real bad match.



regards

Greg N



--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@...> wrote:

>

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> wrote:

> > The Titan was the first mount that defeated me.

>

> Oh, The Mighty Titan! :)

>

> I really couldn't understand why you had all the issues with it, and

> felt bad that you had to go through it. Seems that particular mount

> just liked the warmer climate :)

>

> Mine has been fully operational for three years now, with no

> adjustments after the first winter. It's been sitting outside all

> this time, in 10F to 100F degree weather, rain, snow, etc. It's

> covered up by a tarp, but that's all the protection it has from the

> elements (and the fauna).

>

> The biggest issue I've had to deal with was a large bee hive on the

> pier, under the tarp. Thankfully, they didn't decide to build the

> hive in the worm/gear area! :-)

>

> Regards,

>

> -Paul

>



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

#38506 Jul 25, 2008

Well Greg, it just goes to show that even well made items will have a

production problem, usually 1-3 per 100 items or so. Too bad that you

had to get one of those. :^(

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> Yeah and I lost somewhere between $1500 and $2k on it too, for what

> with various costs to have it shipped, "repaired" (repairs did

> nothing), and marking it down to sell at a loss (I bought used, but

> sold at a lower price than I bought).

>

> It was a real bad match.

>

> regards

> Greg N

>

>

> --- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@> wrote:

> >

> > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> > wrote:

> > > The Titan was the first mount that defeated me.

> >

> > Oh, The Mighty Titan! :)

> >

> > I really couldn't understand why you had all the issues with it, and

> > felt bad that you had to go through it. Seems that particular mount

> > just liked the warmer climate :)

> >

> > Mine has been fully operational for three years now, with no

> > adjustments after the first winter. It's been sitting outside all

> > this time, in 10F to 100F degree weather, rain, snow, etc. It's

> > covered up by a tarp, but that's all the protection it has from the

> > elements (and the fauna).

> >

> > The biggest issue I've had to deal with was a large bee hive on the

> > pier, under the tarp. Thankfully, they didn't decide to build the

> > hive in the worm/gear area! :-)

> >

> > Regards,

> >

> > -Paul

> >

>



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

#38507 Jul 25, 2008

Greg wrote: > Well AP has the reputation for doing everythign right. And it's real

> nice stuff. Real nice.

>

> But let me tell you this: the AP dsc design is *incredibly* inferior

> to the one Scott designed and still sells. It looks better, but it is

> fatally flawed unless modified. Details and all are in the Argo Navis



Greg, your AP mount must be an old non-GTO mount, correct? (None of the GTO

mounts have DSCs). I think that DSCs have not been shipped in new AP mounts

for several years now (maybe 5+ years). The current mounts are controlled by

servos and are *far* more accurate (a fraction of an arc-sec resolution)

than the DSCs.



-Ray



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

#38509 Jul 25, 2008

My experience roughly parallels yours, Vincent. The PE (uncorrected) of

my MI-250 provides appears to be below the quoted 3-5 arc seconds in the

reference. The worst I've measured, again with no Gemini PEC, was 2.3

arc seconds. As important the PE is smooth with no hard to correct

spikes such as I "enjoyed" with my LX200 several years ago :-). With a

PemPro correction run the mount's PE is correctable to be well under

under 2.0. But frankly, that's hardly worth the effort...guiding takes

care of the PE quite nicely. The diamond lapping of the MI-250 gears

seems to do the trick in driving down the PE on those mounts.



If anyone wishes to look up the PemPro data you'll see that the G-11 PE

with PemPro-generated PE corrections is quite excellent, too. So it's

possible to achieve G-11 results similar to those of the uncorrected

MI-250. Such specs are not at all outlandish.



CS,



Gary











Vincent Huang wrote: > I don't know why the condensending tone but I'll bite.

>

> I think what Larry is trying to say is the error will be between 3-5 arc

> secs. And from the many MI250 owners I've talked to, the range does indeed

> fall in between those numbers. If it doesn't, Larry would be happy to talk

> you through adjusting the worm to see if it somehow shifted during

> transport.

>

> I measured mine at 2.5 arc secs.

>

> VH

>

> On Wed, Jul 23, 2008 at 8:44 PM, Dennis Persyk dpersyk@...> wrote:

>

>

>> Mountain Instruments . now here we see some interesting, I'd call

>> them amusing, specs. I quote from

>> www.mountaininstruments.com/pages/mi250Go-To.html

>> "Perridoc (sic) error is very low and smooth. Average 3-5 arc sec.

>>

>

>

>







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

#38510 Jul 25, 2008

I agree with Vince that the MI-250 PEC often falls between 3-5"

uncorrected. Much depends on the mount's load and worm adjustment

when measuring uncorrected PE. My non-corrected PE has been as low

as 2.5" with light loads, however even with my current heavily loaded

three-scope imaging setup (10" LX200R, NP-127, & TMB80)

www.horizontalheavens.com/Trio-NP127-TMB80-LX200R.jpg



my uncorrected 5.81" PE corrected to just 1.49" P-to-P:

www.horizontalheavens.com/PemPro_8-6-2006.jpg



At such low PEC numbers, seeing starts to become the larger

issue/concern.

Michael Howell





--- In Losmandy_users@yahoogroups.com, "Vincent Huang"

vhuang168@...> wrote: >

> I don't know why the condensending tone but I'll bite.

>

> I think what Larry is trying to say is the error will be between 3-

5 arc > secs. And from the many MI250 owners I've talked to, the range

does indeed > fall in between those numbers. If it doesn't, Larry would be happy

to talk > you through adjusting the worm to see if it somehow shifted during

> transport.

>

> I measured mine at 2.5 arc secs.

>

> VH

>

> On Wed, Jul 23, 2008 at 8:44 PM, Dennis Persyk dpersyk@...> wrote:

>

> > Mountain Instruments . now here we see some interesting, I'd

call > > them amusing, specs. I quote from

> > www.mountaininstruments.com/pages/mi250Go-To.html

> > "Perridoc (sic) error is very low and smooth. Average 3-5 arc sec.

> > Recent Activity

> >

> > - 10

> > New

Membersgroups.yahoo.com/group/Losmandy_users/members;_ylc=X3oD

MTJmYzBwYjI3BF9TAzk3MzU5NzE0BGdycElkAzIxMDM1MzAEZ3Jwc3BJZAMxNzA1MDgyOD

A2BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzEyMTY4NzEwNDQ-> > > - 3

> > New

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> > New

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> >

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2xrA3ZnaHAEc3RpbWUDMTIxNjg3MTA0NA--> > > Yahoo! News

> >

> > Fashion

Newsus.ard.yahoo.com/SIG=13ohlmu3c/M=493064.12016309.12445701.

8674578/D=groups/S=1705082806:NC/Y=YAHOO/EXP=1216878245/L=/B=0BypAULaX

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-> > >

> > What's the word on

> >

> > fashion and style?

> > Yahoo! Finance

> >

> > It's Now

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m/evt=50284/*finance.yahoo.com/personal-finance> > >

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> >

> > advice & more.

> > Dog Groups

> >

> > on Yahoo!

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> > .

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> >

> >

>

>

> [Non-text portions of this message have been removed]

>



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

#38517 Jul 26, 2008

Data is impossible to get. I had a number of unsolicited emails from

people who had formerly owned titans and sold them. This is true of

almost every mount, there are some that just aren't up to speed, but

one never knows what the error rate is.





regards

Greg N

--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

>

> Well Greg, it just goes to show that even well made items will have a

> production problem, usually 1-3 per 100 items or so. Too bad that you

> had to get one of those. :^(

> Floyd

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@> wrote:



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

#38519 Jul 26, 2008

Yes and no Ray. The old DSCs on the APs never got their maximum

pointing accuracy because of the inherent design flaw in the

encoder-to-mount ("aluminum wheel") system that resulted from the

decision to design an encoder that looked good rather than worked good.



The AP *paddle* is not going to give sub arc second *pointing*.

*Pointing* is what this is about, not *angular resolution* (within

limits). The fraction of an arc second *resolution* on the AP and

other servo systems is great to have.



The Ap *paddle* however is not optimized to take advantage of that

resolution. Because it has no compensation for polar alignment (MA,

ME, IA, IE) and no compensation for orthagonality (NP) and no

compensation for other things (DCEC, DCES, CH, TF, etc.), the AP

pointing with the *paddle* will be pretty poor, which is why people

need to use the dumb SYNCH command.



If the AP *paddle* had Gemini capabilities you would get pointing

accuracy below 5 arc minutes routinely even with polar misalignment

and SYNCH would not be part of the program. Argo Navis has no SYNCH.

It doesn't need one because it models the mount it is on and you get

all-horizon accuracy.



If you use your AP900GTO with T-point and pop the $250 for it and

carry a laptop & power supply for it to the field, you'll get better

pointing accuracy because T-point has all those variables.



The fact is that my Argo Navis on the AP900QMD or the G11 delivers

superior pointing accuracy with 10,000 tics than the AP900GTO paddle

with two million +.



The resolution that the servo systems have is like a Lamborghini

engine with a Corolla transmission, unless they are coupled to some

kind of modeling system.



My AP900QMD has excellent pointing accuracy, to sum up. I would put

it up against the current AP *paddle* system no problem. For people

that have laptops and do 50 or 100 star pointing models and leave it

in the observatory, they will get superior pointing accuracy to mine.

Someone who takes a laptop with T point out into the field and does a

10 point model for portable use will get only a slight marginal

improvement over what I get with the AP900QMD (as modified and

equipped with Argo Navis). One or two arc minutes in essence, and

even some of that will depend on the OTA.



Although I think concerns about image shift during focus are

exaggerated on the C14, at high power it is about 1-2 arc minutes so

how I focus affects how I signal to the mount system where I am

pointed. This will show up as variability in the the position inputs

which will get modeled as a 1-2 arc minute error no matter how many

zillion tics I have in my encoders.



The 900QMD is a good mount. Some day I might consider a GTO but not

till AP builds some capability into the paddle. Or if I definitively

flip to observing and resign myself to powering a laptop. The reason

I don't want a laptop is I don't want to power it. I already carry 80

amp hours to feed my dew heaters.



An un-modified QMD with 4,000 tic encoders and OEM arrangements on the

encoders will, by contrast, get pointing accuracy of maybe 40 arc

minutes which is sloppy but satisfy most of AP's refractor owners who

have no idea what good pointing is. With Argo Navis and the coupling

modification I get about a 2 arc minute RMS and 4 arc minute PSD.



It's really insane. AP should just contract with Argo Navis. It's an

excellent portable pointing system with one of the best databases in

the industry and a great interface.



regards

Greg N



--- In Losmandy_users@yahoogroups.com, "Ray Gralak" rgr@...> wrote:

>

> Greg wrote:

> > Well AP has the reputation for doing everythign right. And it's real

> > nice stuff. Real nice.

> >

> > But let me tell you this: the AP dsc design is *incredibly* inferior

> > to the one Scott designed and still sells. It looks better, but it is

> > fatally flawed unless modified. Details and all are in the Argo Navis

>

> Greg, your AP mount must be an old non-GTO mount, correct? (None of

the GTO

> mounts have DSCs). I think that DSCs have not been shipped in new AP

mounts

> for several years now (maybe 5+ years). The current mounts are

controlled by

> servos and are *far* more accurate (a fraction of an arc-sec resolution)

> than the DSCs.

>

> -Ray

>







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

#38521 Jul 26, 2008

Remember in theory you need to use the feeler gauges BECAUSE you have

independent bearing blocks. The worm hits the worm wheel at a

tangent. This is true no matter where you place it. Once you have

the bearings squared to the worm (so it seems to me) the problems are

basically taken care of. (I don't think my issues with the Titan were

related to the worm gapping but I could be wrong. Lord knows I tried

MANY different positions including those recommended by other users).

The only other issue is the connection to the motor, but my

understanding is the Oldham basically deals with that, that's what

it's for.



regards

Greg N



--- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@...> wrote:

>

> Hi Greg,

> That sounds quite easy all right.

> Not sure I would go to the expense of either option for the DEC, not

> really needed I think.

> Floyd

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@> wrote:

> >

> > Franck's directions suggested 1mm of play as measured at the *very

> > end* of the counterweight shaft. There was about 3x to 4x that much

> > when I did the test that you see posted on astromart. Now I've cut it

> > down. (I had originally understood the directions to mean 1mm *at the

> > gear*).

> >

> > This block is so easy to adjust that if the play bothers me in the

> > field I would have no problem pulling out an Allen wrench and snugging

> > it up.

> >

> > Personally I think I've had it with separate bearing blocks. I'm

> > really glad not to be there any more. I'll keep the ones I have in

> > case some extremity requires me to change. I'm still mulling over

> > what to do about Dec. There's no point in Ovision for Dec but it

> > might be no point in the Martin block either. Right now Dec works

> > fine and I'm inclined to leave it. But I *do* have a brass worm here

> > that I haven't installed; when the impulse to fuss with the mount

> > comes, that's probably what will happen.

> >

> > regards

> > Greg N

> >

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@> wrote:

> > >

> > > Hi Greg,

> > > What do you use to set the Ovision if you do not use a feeler gauge?

> > > Do you just use the feel method of grabbing it and seeing how

much it

> > > moves and then move the block or what?

> > > I use the feeler gauges by setting the lash to tight, then add .001"

> > > or more to the gap until it feels about right. The gauges just

give me

> > > control over the changes I make, so that I don't just

guesstimate over

> > > and over, until maybe I get it right. I guess that just comes from

> > > being a mechanic for over 30 years. :^)

> > > Just wondering?

> > > By the way, I do not feel that my testing can be considered the

> > > absolute proof of anything. I may or may not have done this

right, so

> > > I think I will just back out of this at this time. Seems like the

> > > demands for perfection in testing are probably beyond what I want to

> > > get involved with, after all I am just trying to take

photographs, not

> > > get an engineering degree. (Grin)

> > > ;^)

> > > Floyd

> > > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

wrote:

> > > >

> > > > Paramount ME guarantees the PE.

> > > > Ovision guarantees its PE! So there you have something.

> > > >

> > > > Your main point however is one of the thigns that bothers me

> about the

> > > > good results we've been seeing with the brass worms: I don't

> know what

> > > > % of cases it represents, and how replicable it is. Floyd may

> say it

> > > > is easy to use a feeler gauge with the worm setup and that may be

> > > > true. I had oodles of advice about using the feeler gauge when I

> > > > owned a titan. And I had at least four feeler gauges which I

> used both

> > > > in the field and in garage tests.

> > > >

> > > > I got pretty tired of that pretty fast. No feeler gauge is

required

> > > > for the Ovision, which is territory I'm comfortable with. I

> don't use

> > > > one with my AP900 either. Never tested the PE on that.

> > > >

> > > > regards

> > > > Greg N

> > > >

> > > >

> > > > --- In Losmandy_users@yahoogroups.com, "Dennis Persyk" dpersyk@>

> > > > wrote:

> > > > >

> > > > > Glad you raised the issue of PE specs, Greg. In particular,

> Astro-

> > > > > Physics is one of a very few (maybe the only?) mount suppliers

> that

> > > > > *guaranties* a maximum PE. The value of 7 arc seconds applies to

> > the

> > > > > Mach1GTO; the AP1200GTO has a 5 arc second limit. I could tell

> you

> > > > > what Roland measured on my mount before he shipped it, but that

> > would

> > > > > just be bragging.

> > > > >

> > > > > What do other suppliers have in the way of PE specs?

> > > > > Meade . none whatsoever; PEs of 120 arc seconds for LX200GPS

> scopes

> > > > > (on wedges) have been reported by reputable imagers

> > > > > Celestron . none whatsoever

> > > > > Losmandy . none whatsoever

> > > > > Mountain Instruments . now here we see some interesting, I'd

call

> > > > > them amusing, specs. I quote from

> > > > > www.mountaininstruments.com/pages/mi250Go-To.html

> > > > > "Perridoc (sic) error is very low and smooth. Average 3-5 arc

> sec."

> > > > >

> > > > > Now one doesn't need a PhD in Math to note that average is a

> single-

> > > > > valued function, and not a range of values. But more to the

> > point,

> > > > > an "average PE" is no guide to what you will actually get when

> you

> > > > > open the box and test the mount. Indeed, what if the mount you

> > get is

> > > > > in fact several standard deviations removed from the average

> value?

> > > > > In other words, an outlier with a PE of, say, 80 arc seconds.

> > Is the

> > > > > 80 arc second PE out of "spec". Legally, no.

> > > > >

> > > > > It bothers me that mount manufacturers (except perhaps A-P) do

> not

> > > > > adequately specify their products so that the purchaser

knows up

> > > > > front what they can expect from a worst-case perspective. We're

> > just

> > > > > rolling the dice.

> > > > >

> > > > > Soapbox dismounted.

> > > > >

> > > > > Clear skies,

> > > > >

> > > > > Dennis Persyk

> > > > > Igloo Observatory Home Page dpersyk.home.att.net

> > > > > Hampshire, IL

> > > > > Pier Design home.att.net/~dpersyk/Pier_Design.htm

> > > > >

> > > > > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@>

> > > > > wrote:

> > > > > >

> > > > > > AP only certifies to 7 arc seconds peak to peak, so I'd say

> you're

> > > > > > doing better than AP. But the 900 does have more load

> capacity.

> > > > > greg n

> > > > > >

> > > > >

> > > >

> > >

> >

>







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

#38522 Jul 26, 2008

We're talking about two different things. I believe the precision of the

servo movements in a new AP900/1200 has about 26,000,000 ticks in a 360

degree revolution, which is about 2600x the greatest potential accuracy of

the argo narvis and even more of a factor over the old technology OEM

encoders in the 900QMD. Think of the servos as having an encoder with 0.05

arc-sec "ticks" - so using an Argo Narvis would actually greatly lower the

maximum resolution possible.



That said, there just needs to be a pointing model to use the accuracy of

the servos. I think I saw that you're on the APGTO list so you must have

seen that this feature is in development.



-Ray

> Yes and no Ray. The old DSCs on the APs never got their maximum

> pointing accuracy because of the inherent design flaw in the

> encoder-to-mount ("aluminum wheel") system that resulted from the

> decision to design an encoder that looked good rather than

> worked good.

>

> The AP *paddle* is not going to give sub arc second *pointing*.

> *Pointing* is what this is about, not *angular resolution* (within

> limits). The fraction of an arc second *resolution* on the AP and

> other servo systems is great to have.

>

> The Ap *paddle* however is not optimized to take advantage of that

> resolution. Because it has no compensation for polar alignment (MA,

> ME, IA, IE) and no compensation for orthagonality (NP) and no

> compensation for other things (DCEC, DCES, CH, TF, etc.), the AP

> pointing with the *paddle* will be pretty poor, which is why people

> need to use the dumb SYNCH command.

>

> If the AP *paddle* had Gemini capabilities you would get pointing

> accuracy below 5 arc minutes routinely even with polar misalignment

> and SYNCH would not be part of the program. Argo Navis has no SYNCH.

> It doesn't need one because it models the mount it is on and you get

> all-horizon accuracy.

>

> If you use your AP900GTO with T-point and pop the $250 for it and

> carry a laptop & power supply for it to the field, you'll get better

> pointing accuracy because T-point has all those variables.

>

> The fact is that my Argo Navis on the AP900QMD or the G11 delivers

> superior pointing accuracy with 10,000 tics than the AP900GTO paddle

> with two million +.

>

> The resolution that the servo systems have is like a Lamborghini

> engine with a Corolla transmission, unless they are coupled to some

> kind of modeling system.

>

> My AP900QMD has excellent pointing accuracy, to sum up. I would put

> it up against the current AP *paddle* system no problem. For people

> that have laptops and do 50 or 100 star pointing models and leave it

> in the observatory, they will get superior pointing accuracy to mine.

> Someone who takes a laptop with T point out into the field and does a

> 10 point model for portable use will get only a slight marginal

> improvement over what I get with the AP900QMD (as modified and

> equipped with Argo Navis). One or two arc minutes in essence, and

> even some of that will depend on the OTA.

>

> Although I think concerns about image shift during focus are

> exaggerated on the C14, at high power it is about 1-2 arc minutes so

> how I focus affects how I signal to the mount system where I am

> pointed. This will show up as variability in the the position inputs

> which will get modeled as a 1-2 arc minute error no matter how many

> zillion tics I have in my encoders.

>

> The 900QMD is a good mount. Some day I might consider a GTO but not

> till AP builds some capability into the paddle. Or if I definitively

> flip to observing and resign myself to powering a laptop. The reason

> I don't want a laptop is I don't want to power it. I already carry 80

> amp hours to feed my dew heaters.

>

> An un-modified QMD with 4,000 tic encoders and OEM arrangements on the

> encoders will, by contrast, get pointing accuracy of maybe 40 arc

> minutes which is sloppy but satisfy most of AP's refractor owners who

> have no idea what good pointing is. With Argo Navis and the coupling

> modification I get about a 2 arc minute RMS and 4 arc minute PSD.

>

> It's really insane. AP should just contract with Argo Navis. It's an

> excellent portable pointing system with one of the best databases in

> the industry and a great interface.

>

> regards

> Greg N

>

> --- In Losmandy_users@yahoogroups.com

> mailto:Losmandy_users%40yahoogroups.com> , "Ray Gralak"

> rgr@...> wrote:

> >

> > Greg wrote:

> > > Well AP has the reputation for doing everythign right.

> And it's real

> > > nice stuff. Real nice.

> > >

> > > But let me tell you this: the AP dsc design is

> *incredibly* inferior

> > > to the one Scott designed and still sells. It looks

> better, but it is

> > > fatally flawed unless modified. Details and all are in

> the Argo Navis

> >

> > Greg, your AP mount must be an old non-GTO mount, correct? (None of

> the GTO

> > mounts have DSCs). I think that DSCs have not been shipped in new AP

> mounts

> > for several years now (maybe 5+ years). The current mounts are

> controlled by

> > servos and are *far* more accurate (a fraction of an

> arc-sec resolution)

> > than the DSCs.

> >

> > -Ray

> >

>

>

>

>

>







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

#38523 Jul 26, 2008

Vincent averaging 3-5 arc seconds implies that there are some higher

and some lower. It is different from "guaranteed in the range of 3 to

5 arc seconds."



I note that some people sort of just get things down when they're

writing and don't pay attention to all the nuances. Larry may very

well think that he's selling mounts in the 3-5 arc second category and

that may be what he intended. But "guaranteed 3-5 arc seconds peak to

peak" is not the same as saying "averaging 3-5 arc seconds."



One may reflect on the notion of average life span. If you're 50 you

might think "well I've got 27 years to go."



But many of us will have much less than that. We tend to forget that

the average is simply the numeric point between the high and low values.



regards

Greg N







--- In Losmandy_users@yahoogroups.com, "Vincent Huang" vhuang168@...>

wrote: >

> I don't know why the condensending tone but I'll bite.

>

> I think what Larry is trying to say is the error will be between 3-5 arc

> secs. And from the many MI250 owners I've talked to, the range does

indeed > fall in between those numbers. If it doesn't, Larry would be happy

to talk > you through adjusting the worm to see if it somehow shifted during

> transport.

>

> I measured mine at 2.5 arc secs.

>

> VH

>

> On Wed, Jul 23, 2008 at 8:44 PM, Dennis Persyk dpersyk@...> wrote:

>

> > Mountain Instruments . now here we see some interesting, I'd call

> > them amusing, specs. I quote from

> > www.mountaininstruments.com/pages/mi250Go-To.html

> > "Perridoc (sic) error is very low and smooth. Average 3-5 arc sec.

> > Recent Activity

> >

> > - 10

> > New

Membersgroups.yahoo.com/group/Losmandy_users/members;_ylc=X3oDMTJmYzBwYjI3BF9TAzk3MzU5NzE0BGdycElkAzIxMDM1MzAEZ3Jwc3BJZAMxNzA1MDgyODA2BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzEyMTY4NzEwNDQ-> > > - 3

> > New

Photosgroups.yahoo.com/group/Losmandy_users/spnew;_ylc=X3oDMTJmN3JtMnU5BF9TAzk3MzU5NzE0BGdycElkAzIxMDM1MzAEZ3Jwc3BJZAMxNzA1MDgyODA2BHNlYwN2dGwEc2xrA3ZwaG90BHN0aW1lAzEyMTY4NzEwNDQ-> > > - 2

> > New

Linksgroups.yahoo.com/group/Losmandy_users/links;_ylc=X3oDMTJnY3RtZGFhBF9TAzk3MzU5NzE0BGdycElkAzIxMDM1MzAEZ3Jwc3BJZAMxNzA1MDgyODA2BHNlYwN2dGwEc2xrA3ZsaW5rcwRzdGltZQMxMjE2ODcxMDQ0> > >

> > Visit Your Group

> >

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> >

> > Fashion

Newsus.ard.yahoo.com/SIG=13ohlmu3c/M=493064.12016309.12445701.8674578/D=groups/S=1705082806:NC/Y=YAHOO/EXP=1216878245/L=/B=0BypAULaX9g-/J=1216871045300521/A=3848621/R=0/SIG=12u6o6g3h/*news.yahoo.com/i/1597;_ylt=A9FJqa5Gxa5E2jgAYQKVEhkF;_ylu=X3oDMTA2MnU4czRtBHNlYwNzbg--> > >

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> [Non-text portions of this message have been removed]

>



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

#38525 Jul 26, 2008

Greg,



Almost the only people that care about high accuracy pointing are doing

imaging.



If you are using a refractor (what AP mostly sells to complement their

mounts) you can put the object on an small chipped ST-7E every time when

accurately polar aligned. You don't really need higher pointing accuracy

until you go to a larger instrument with significant flexure. Then if you

have a larger instrument most people have fixed observatories where it has

made sense to buy TPoint for $250, or even cheaper, MaxPoint for $150, or

ACP or PinPoint + CCDAutopilot.



It just hasn't been a high priority because most people haven't cared nor

wanted higher pointing precision for visual use. Once you throw in a CCD

camera there are all kinds of solutions that are alternatives to telescope

modeling. It really is a low priority issue. I've had very few problems

pointing my scopes (refractors, SCTs, and large Newts) without any pointing

model at all.



-Ray





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

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com] On Behalf Of gnowellsct

> Sent: Saturday, July 26, 2008 10:17 AM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] PE Specs was Re: 1 complete worm

> period, no PEC or guiding, G-11 Gemini

>

> Ray I'm the last one to disparage AP mounts--I own one. I am on ap-ug

> not ap-gto.

>

> The software has been in the vaporware stage for many years. Gemini

> has been out for at least ten. When it hit the market that should

> have been a big "HELLO ANYONE AWAKE" to AP. Argo Navis has had its

> modeling system out for 5 or 6 years. Even CGE does better than the

> AP paddle. (Gemini blows away CGE) You got friggin dobs out there with

> mount modeling and AP is totally asleep on the subject.

>

> I don't give a fig whehter it is 2.6 million or 26 million tics

> (someone calculated the Geminis at 2 million or so) because that

> resolution is totally superfluous to amateur pointing models where

> diminishing returns probably start at about 30,000 to 50,000. The

> resolution is that high because the servo design permits it. Good for

> the servos.

>

> AP has been behind the ball on its software. They're in the 90s with

> inferior capability. They have not prioritized it. They are not

> pushing it. They have off-loaded the problem to t-point. When I

> raised it on the group I got an irate reply from the master that no

> one needs that kind of accuracy anyhow (I was talking about under 5

> arc minutes all-horizon). In addition to this, the dscs in the 90s

> were poorly designed.

>

> This is *one of the very few* aspects of AP performance that is behind

> rather than ahead of industry best-standards. It's pretty obvious. I

> calls 'em likes I sees 'em. I LOVE Pentax eyepieces but if you want

> to see me ream them on their total lack of customer support see my

> recent posts on sct-user.

>

> If APGTO had had REAL modeling capability when I was on the market, I

> would have bought it. I was tired of the synching nonsense and the

> bad pointing and Argo Navis had already showed me what good pointing

> was on the G11. I had no intention of going back to the bad old days.

> So I blew off the GTO and got a QMD. Call me ornery that way. I

> wanted pointing accuracy without a laptop and I wanted to get up and

> running on an AP with mount modeling as of two years ago. Argo Navis

> let me do that. AP vaporware did not and still will not/cannot.

> Going for speech recognition instead of modeling in the paddle is as

> fundamental a flaw as going for looks in designing the dscs instead of

> designing functional accuracy. These were mistakes: glitz over

> substance.

>

> Regarding their stability and tracking the mounts are gorgeous and

> among the very best. If one wants pointing accuracy, use a laptop

> with t-point or buy another mount. For my money the G11/Ovision with

> Gemini for portable applications equals the Mach 1 in tracking and

> blows it away in paddle capability at 1/2 the cost (factoring in the

> accessories that you have to buy with the Mach 1 that come with the

> G11).

>

> Tak mounts are just as far behind on this as the AP. Shame on them.

>

> regards

> Greg N

>

> --- In Losmandy_users@yahoogroups.com

> mailto:Losmandy_users%40yahoogroups.com> , "Ray Gralak"

> rgr@...> wrote:

> >

> > We're talking about two different things. I believe the

> precision of the

> > servo movements in a new AP900/1200 has about 26,000,000

> ticks in a 360

> > degree revolution, which is about 2600x the greatest potential

> accuracy of

> > the argo narvis and even more of a factor over the old

> technology OEM

> > encoders in the 900QMD. Think of the servos as having an encoder

> with 0.05

> > arc-sec "ticks" - so using an Argo Narvis would actually greatly

> lower the

> > maximum resolution possible.

>

>

>

>

>







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

#38526 Jul 26, 2008

I don't give a fig whehter it is 2.6 million or 26 million tics

> (someone calculated the Geminis at 2 million or so) because that

> resolution is totally superfluous to amateur pointing models where

> diminishing returns probably start at about 30,000 to 50,000. The

> resolution is that high because the servo design permits it. Good for

> the servos.



Actually the accuracy makes a lot of difference compared to the Argo Narvis.

When you position the scope with Argo Narvis the accuracy is only to about 2

arc-minutes, which can really be a disadvantage when calculating the

pointing model.



Not only that, the 0.05 arc-sec accuracy defines the smallest PEC correction

or Dec movement that can be made, both of which are extremely important for

autoguiding and imaging.



-Ray



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

#38530 Jul 26, 2008

Hi Greg,

Unfortunately, very true!

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> Data is impossible to get. I had a number of unsolicited emails from

> people who had formerly owned titans and sold them. This is true of

> almost every mount, there are some that just aren't up to speed, but

> one never knows what the error rate is.

>

>

> regards

> Greg N

>

> --- In Losmandy_users@yahoogroups.com, "Floyd Blue" fblue@> wrote:

> >

> > Well Greg, it just goes to show that even well made items will have a

> > production problem, usually 1-3 per 100 items or so. Too bad that you

> > had to get one of those. :^(

> > Floyd

> > --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@> wrote:

>



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

#38531 Jul 26, 2008

Accuracy matters for visual observers who are chasing visual objects

> where it is critical to have the object as centered as possible rather

> than merely in the field of view. If one is chasing a faint Palomar



This is really a pointless argument... with the Argo Navis your accuracy is

at most 2 arc-minutes, so it wouldn't have helped you much. Just syncing to

the nearest star would allow accuracy to within 10 arc-secs. (LOL!)

> in a 14" aperture or a 1 arc second planetary--visually, not

> photographically--it helps to know where it is or have confidence it

> is more or less centered because you're going to be staring at that

> field a lonnng time before you actually *see* anything and even then

> it you might have negative results for the night. In some cases (I

> have chased 1 arc second planetaries in the Milky way star field) the

> field of view is so insanely stuffed with stars that even star hopping

> isn't much help. In fact the only thing that works for me is to have

> accurate pointing + a spectroscopic grid which streaks the regular

> stars and leaves the planetaries sitting there small and round.



Hmmm... lot's of people I know star hop with large dobs (20"+) without

tracking. It just takes a little bit of experience. I have star-hopped in my

18" many times when I was too lazy to align using the (only 4000 step :-)

encoders on my dob.

> Let's talk about applications for a minute. I found Pal 14, I

> sketched it, I verified my sketch on the Strasbourg database, I

> notified Brian Skiff that the catalog entry location was off by about

> three arc minutes, he looked at the results and verified them, and he

> took it up with other catalog officials, and the positional error got

> fixed.

>

> That is the context. I don't like being told by Roland or anyone else

> that I don't need pointing accuracy for visual. I have in my scope at

> most 43 arc minutes (with a 40mm 70degree XW40) and when I leave a

> 10mm in because I am going for something really really difficult I

> have about 10 arc minutes which is a very chip-like application.



I think you just need a little more practice. Using a telrad I am almost

always able to put a target in the eyepiece of my 18" dob with a 20 Nagler.

And if I had it wrong a little star hopping I could find what I was looking

for.

> So it is incorrect, and frankly, not a little parochial, to say that

> accuracy only matters to imagers. If one is chasing Messiers and the



Yes, if you are a beginner or directionally challenged then you might have

some trouble star hopping, but as you develop your skills you should be able

to find very faint fuzzies without a computer. Many people do this at star

parties every month.

> brighter NGCs in a five inch scope, well OK, one does not need

> accuracy. That's why Roland could get by with those slipping

> encoders. But any time one is pushing the instrument's limiting

> magnitude one needs pointing accuracy especially in those cases where

> there is not a highly distinctive asterism to nail the location (an

> easy object to find via asterism is IC4617; that is to say, it is easy

> to see where it should be, even if one can't see it).



Yea, I remember seeing IC4617 first time about 10+ years ago in my dob. In

fact some other more experienced observers were surprised - until they

looked through my eyepiece. :-)

> But then that gets into the point that Tak and AP blow off the

> pointing model because people don't chase a lot of hard objects in 6

> inch apertures. The dob guys are mostly visual, have large apertures,

> and chase faint objects: the result: these wood and tubed behemoths

> have a pointing system that puts AP and Tak to shame. And thank God



And most don't need a pointing system. In fact in some circles it was

considered cheating if you use a pointing computer on a dob. :-)

> get myself. As far as pointing accuracy goes, the systems are

> equivalent under these conditions, notwithstanding the huge delta in

> tics.



It doesn't really matter in any practical sense. If you are working visual

your skills will get you there, and, if you are automated, plate solving

corrects the position.

> I speak to the question of portable usage and setup, approximate

> (polar scope) alignment, and ten star or fewer models. The pointing

> accuracy of the higher tic system is not commensurate, under these

> conditions, the much larger number of tics at its disposal. The



Sure it makes a huge difference. If I sync on a nearest mag 3 star I can

usually have the mount point to within 10 arc-secs of a target. But that is

not necessary because the object is going to be in the field of view of

almost any instrument you use provided you are well polar aligned.

> separate argument that accuracy need not be there, all of which goes

> to someone else's needs, not mine: I want pointing accuracy.

>

> Some of us live in places with trees or lights. We take the scope

> out, set it up, take it down. We want pointing accuracy. What's so

> hard about that?

>

> I also don't want to synch. It is a waste of time. It is obsolete.



OK, but if you are setting up your scope with a pointing model you had to

align to something... right?

> As in take the scope out our of the car trunk, set it up, and find the

> object without requiring a laptop. We apparently are not disputing

> that then. We are simply saying that some people's needs are

> different. AP go-to mounts (as sold today) are not for people who want

> pointing accuracy out of the paddle. And I think we should readily



If you are using a refractor (like what AP mostly sells) I guarantee you

that pointing accuracy is excellent once polar aligned and synced to one

star. All Sky you will be able to put the object a not-so-widefield

eyepiece. I know, I have done it. You probably haven't because your mount is

not one of the current GOTOs.

> agree that an encoder mount interface with designed in slippage that

> one is told to fix by crimping with pliers is inferior to the G11

> hardware, which is with reference to AP pointing in the 90s. So for

> two decades AP has not been in the lead with regard to pointing

> accuracy for people who don't have observatories in clear dark sites.



Why don't you just buy a new mount instead of using the old technology in

your 900QMD? Your mount is really what is outdated.

> We agree that AP off-loads the problem to software vendors and that it

> is not a high priority for AP or for imagers who lug around laptops



Sorry, no we don't agree. I already sent you a private email detailing why.

Why don't you answer that email instead of clogging the list with your

complaints about a mount that AP stopped producing years ago? :-)



Thanks,



-Ray







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

#38535 Jul 26, 2008

Actually Ray I'm complaining about the current generation of AP paddle. I see this is an

impasse. In your opinion I should star hop, get a laptop, or synch. I disagree. I was

wondering however about the last part of my post, the Gemini servo resolution vs AP servo

resolution and the ramifications on PE. Greg N



--- In Losmandy_users@yahoogroups.com, "Ray Gralak" rgr@...> wrote:

>

> > Accuracy matters for visual observers who are chasing visual objects

> > where it is critical to have the object as centered as possible rather

> > than merely in the field of view. If one is chasing a faint Palomar



> -Ray

>



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

#38537 Jul 26, 2008

Greg,

> Actually Ray I'm complaining about the current generation of

> AP paddle. I see this is an

> impasse. In your opinion I should star hop, get a laptop, or

> synch. I disagree. I was



Actually I think I also said there is another more common option... you may

not have to do anything because the object will be in the field of view.

That will likely be so unless you are using a high magnification or a scope

subject to lots of flexure.

> wondering however about the last part of my post, the Gemini

> servo resolution vs AP servo

> resolution and the ramifications on PE. Greg N



You mean this? > I'm not sure that the feasible PEC adjustments .05 arc seconds on AP

> mounts are substantively better than those on Losmandy/Ovision but if

> it is so, it would be something I would remember once I do know,

> because I like to collect these facts, as well as some evaluation of

> their signficance. So I would like to know how relationship of

> Losmandy servo resolution and AP servo resolution relates to the

> question of PEC in an apples to apples comparison as opposed to the

> red herring of high encoder resolution feeding into a paddle that is

> so feeble it can't even use the data.



Just to be clear, pointing accuracy has absolutely nothing to do with the

ability of a mount to move to a precise servo position. The smallest PEC

unit an AP900/1200 can move is about 0.05 arc-seconds. I don't recall what

the minimum unit is for the Gemini, but I believe is it is dependent on

direction (East/West) and the guide rate.



-Ray



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

#38538 Jul 26, 2008

Ray you brought the servo/PE thing up during the course of the

exchange on the AP paddle. It would never have occurred to me to

bring it in at all. I would be interested in knowing if the different

values between the mounts is of any practical significance.



If one turns the mount modeling off on the AN pointing accuracy

diminishes markedly. It essentially becomes a 1990s dsc box with

superior ergonomics and database management.



regards

Greg N

--- In Losmandy_users@yahoogroups.com, "Ray Gralak" rgr@...> wrote:

>

> Greg,

>

> > Actually Ray I'm complaining about the current generation of

> > AP paddle. I see this is an

> > impasse. In your opinion I should star hop, get a laptop, or

> > synch. I disagree. I was

>

> Actually I think I also said there is another more common option...

you may

> not have to do anything because the object will be in the field of view.

> That will likely be so unless you are using a high magnification or

a scope

> subject to lots of flexure.

>

> > wondering however about the last part of my post, the Gemini

> > servo resolution vs AP servo

> > resolution and the ramifications on PE. Greg N

>

> You mean this?

> > I'm not sure that the feasible PEC adjustments .05 arc seconds on AP

> > mounts are substantively better than those on Losmandy/Ovision but if

> > it is so, it would be something I would remember once I do know,

> > because I like to collect these facts, as well as some evaluation of

> > their signficance. So I would like to know how relationship of

> > Losmandy servo resolution and AP servo resolution relates to the

> > question of PEC in an apples to apples comparison as opposed to the

> > red herring of high encoder resolution feeding into a paddle that is

> > so feeble it can't even use the data.

>

> Just to be clear, pointing accuracy has absolutely nothing to do

with the

> ability of a mount to move to a precise servo position. The smallest PEC

> unit an AP900/1200 can move is about 0.05 arc-seconds. I don't

recall what

> the minimum unit is for the Gemini, but I believe is it is dependent on

> direction (East/West) and the guide rate.

>

> -Ray

>



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

#38542 Jul 26, 2008

Ray you brought the servo/PE thing up during the course of the

> exchange on the AP paddle. It would never have occurred to me to

> bring it in at all. I would be interested in knowing if the different

> values between the mounts is of any practical significance.



The reason I brought it in is that you seem to be complaining about the

encoder solution on a mount that no longer exists and for which there will

probably never be a "pointing model" solution from AP. The only solution is

to purchase a servo controlled mount because it has the much higher

precision needed to accurately model pointing errors.

> If one turns the mount modeling off on the AN pointing accuracy

> diminishes markedly. It essentially becomes a 1990s dsc box with

> superior ergonomics and database management.



I have no idea what you are talking about? At least two AP GTO users here

have told you that we don't have problems with pointing. You don't even own

one of the newer servo-controlled mounts so you really are not in a position

to say anything more than maybe that the OEM encoder solution on your 900QMD

sucks. I'm glad that Argo Narvis solved that problem for you.



-Ray







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