VintageBigBlue.org

 

RE: [Losmandy_users] Re: PEC and oldham coupler


Sep 5, 2006

 


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

#30736 Sep 5, 2006

Pity I did not join the group earlier. Hardware problems belong here

rather than on the Gemini group.



I wasted tremendous amount of time with Pempro trying to optimize my

PEC (some 15 plus arcsecs peak to peak). No matter what I did, it

made no difference whatever. Autoguiding with an SBIG camera works

but this is NOT the solution for PE. I bought my G11 about a year

ago based on the specs that talk enthusiastically about the PEC

functionality, especially with Gemini. During the testing of Gemini

L4 I reported and documented problems with my PEC only to be

dismissed by people in that group and ignored by the Goerlichs

(authors of Gemini and Gemini Control Center software).



The lack of communication between Scott Losmandy and the Goerlichs

(in Germany) is amazing. Nowhere during the testing of Gemini the

problem with the non-periodic (i.e., not related to the period of

the worm) problem was mentioned. Rene Goerlich has a Losmandy mount

but he is a programmer first, mechanic last...



I am really upset by this situation. A few hours ago Ray Gralak

wrote

me to do my own research how to fix the problem he identified as

lack of centering of the Oldham coupler, whatever that means. One

would expect that he would provide more help since I am not going to

spend $150 for Pempro (fortunately now in my 60 day trial period) if

it is NOT going to work.



Scott Losmandy is currently not available but he is supposed to be

back by September 8. I sent him a private mail, bit strong for his

taste, perhaps. I prefer not to communicate with manufacturers, I

expect their equipment to work. Well, I should have known better a

year ago before I spent my $3,500 for the mount (including CA

taxes).



Any comment and, most importantly, instructions how to fix this

problem (if it is fixable) will be greatly appreciated through this

forum or privately.



Ladislav Nemec

Big Bear, CA

Minor Planet Center 'observatory' G77, Baldwin Lake



nemecl@...



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

#30738 Sep 6, 2006

Ladislav, don't blame Ray for something he can't do. He doesn't own

a Gemini mount and has no hands-on experience with one (at least I'm

pretty sure he doesn't). I'm not sure why you'd expect him to give

you instructions on how to adjust something he has no experience

with.



Neither is Doc Goerlich to blame, as the problem is not with Gemini.

And believe me, not every G11 has this non-periodic error: mine has

a total PE (without PEC) of under 4 arcseconds, with only about 1

arcsec of non-periodic error which I attributed to the Oldham

coupler.



Adjusting your mount properly is important. Search the archives for

worm/motor-shaft alignment instructions. This is critical -- there

should be a straight line between the motor shaft and the worm. Make

sure the worm blocks are straight and the worm bearings not twisted

in the worm blocks, even by a tiny amount.



Don't forget: you have two complete worm assemblies on the mount, PE

is important only in RA. Swap the motors, swap the gear boxes, swap

the worms and even the worm blocks between DEC and RA, and check

again with PEMPro. You may find a much lower PE and a lower or non-

existent 76-sec periodic component.



Regards,



-Paul

--- In Losmandy_users@yahoogroups.com, "nemecll" nemecl@...> wrote:

>

> Pity I did not join the group earlier. Hardware problems belong

here

> rather than on the Gemini group.

>

> I wasted tremendous amount of time with Pempro trying to optimize

my

> PEC (some 15 plus arcsecs peak to peak). No matter what I did, it

> made no difference whatever. Autoguiding with an SBIG camera works

> but this is NOT the solution for PE. I bought my G11 about a year

> ago based on the specs that talk enthusiastically about the PEC

> functionality, especially with Gemini. During the testing of

Gemini

> L4 I reported and documented problems with my PEC only to be

> dismissed by people in that group and ignored by the Goerlichs

> (authors of Gemini and Gemini Control Center software).

>

> The lack of communication between Scott Losmandy and the Goerlichs

> (in Germany) is amazing. Nowhere during the testing of Gemini the

> problem with the non-periodic (i.e., not related to the period of

> the worm) problem was mentioned. Rene Goerlich has a Losmandy

mount

> but he is a programmer first, mechanic last...

>

> I am really upset by this situation. A few hours ago Ray Gralak

> wrote

> me to do my own research how to fix the problem he identified as

> lack of centering of the Oldham coupler, whatever that means. One

> would expect that he would provide more help since I am not going

to

> spend $150 for Pempro (fortunately now in my 60 day trial period)

if

> it is NOT going to work.

>

> Scott Losmandy is currently not available but he is supposed to

be

> back by September 8. I sent him a private mail, bit strong for his

> taste, perhaps. I prefer not to communicate with manufacturers, I

> expect their equipment to work. Well, I should have known better a

> year ago before I spent my $3,500 for the mount (including CA

> taxes).

>

> Any comment and, most importantly, instructions how to fix this

> problem (if it is fixable) will be greatly appreciated through

this

> forum or privately.

>

> Ladislav Nemec

> Big Bear, CA

> Minor Planet Center 'observatory' G77, Baldwin Lake

>

> nemecl@...

>







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

#30741 Sep 6, 2006

Hello Ladislav,



I know your frustrations when it comes to spending $$$$ on a mount

and having to do some work to get it to where you can use it for your

intended use. I am not saying that mounts don't need tweaking

however, but they should not have to be repaired to get them to work

out of the box (more info on that can be found at

www.helixgate.net/g11.html ). Having experience in mechanics

myself I was able to repair my new G11's fairly random PE camel type

humps (on each side of the sinusoidal curve) as well as a few other

issues without sending the parts back and waiting. I addressed the

issue with the tight and mis-aligned Oldham coupler easily and it

totally eliminated the sudden PE humps, most probably due to friction

loading and un-loading, with a simple use of a Dremel bit to hone the

bore opening in the nylon coupler. Please refer to message ID # 27966

for the details.

Personally I thing the Oldham coupler design is not the best for a

mount used for imaging but with a little work can be made to perform

well.

I can answer any question either public or private.



Best Regards,

Mike Siniscalchi



www.helixgate.net

--- In Losmandy_users@yahoogroups.com, "nemecll" nemecl@...> wrote:

>

> Pity I did not join the group earlier. Hardware problems belong

here

> rather than on the Gemini group.

>

> I wasted tremendous amount of time with Pempro trying to optimize

my

> PEC (some 15 plus arcsecs peak to peak). No matter what I did, it

> made no difference whatever. Autoguiding with an SBIG camera works

> but this is NOT the solution for PE. I bought my G11 about a year

> ago based on the specs that talk enthusiastically about the PEC

> functionality, especially with Gemini. During the testing of Gemini

> L4 I reported and documented problems with my PEC only to be

> dismissed by people in that group and ignored by the Goerlichs

> (authors of Gemini and Gemini Control Center software).

>

> The lack of communication between Scott Losmandy and the Goerlichs

> (in Germany) is amazing. Nowhere during the testing of Gemini the

> problem with the non-periodic (i.e., not related to the period of

> the worm) problem was mentioned. Rene Goerlich has a Losmandy mount

> but he is a programmer first, mechanic last...

>

> I am really upset by this situation. A few hours ago Ray Gralak

> wrote

> me to do my own research how to fix the problem he identified as

> lack of centering of the Oldham coupler, whatever that means. One

> would expect that he would provide more help since I am not going

to

> spend $150 for Pempro (fortunately now in my 60 day trial period)

if

> it is NOT going to work.

>

> Scott Losmandy is currently not available but he is supposed to be

> back by September 8. I sent him a private mail, bit strong for his

> taste, perhaps. I prefer not to communicate with manufacturers, I

> expect their equipment to work. Well, I should have known better a

> year ago before I spent my $3,500 for the mount (including CA

> taxes).

>

> Any comment and, most importantly, instructions how to fix this

> problem (if it is fixable) will be greatly appreciated through

this

> forum or privately.

>

> Ladislav Nemec

> Big Bear, CA

> Minor Planet Center 'observatory' G77, Baldwin Lake

>

> nemecl@...

>



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

#30742 Sep 6, 2006

Paul,

you are, as almost alwyas, right. No matter what the cause of this 77

second 'periodic error' is, it is a HARDWARE not software problem (in

either Rene's Gemini code or Ray's Pempro). It has bee very

unproductive on my part to become kind of 'emotional' and blame

anyone - this is just one of the things amateurs with limited means

have to cope with.



I was briefly considering to spend some $12,000 for Software Bisque

Paramount but I dismissed the idea as not appropriate to my financial

situation. Who knows, even that mount may have its glitches...



Recently I 'played' with the RA worm assembly and for no apparent

reason the RA jumps and humps were diminished. Now I know what to

look for and this is the first and fairly easy step. If I succeed

I'll try to describe my 'procedure' in some detail here.



I am not worred about the DEC assembly - except for tracking unusual

objects continuous DEC motion is not needed. Bad DEC motion can of

course affect the autoguiding. In any case, first things first.



Going back to Gemini. I actually detected the problem months ago and

I reported it on the Gemini L4 group without having any idea what the

problem was. Simply: my tracking WITH PEC was worse than without it.

At that time I attributed it to some glitches in the Gemini code

still under development. It was dismissed by the group and by Rene -

interestingly enough, as far as I remember, nobody mentioned the

Oldham coupler (or other hardware glitch) as a possible reason for my

then 'inexplicable' results. Since then very similar experiences was

reported on the CCDWare users group - I did not read all the messages

but one was just like my own 'Worse with PEC than without it'.



It is satisfying to confirm my results months back - the science (?)

of G11 is making slow but sure progress and we all (first of all I)

should stop being emotional...



Regards, Ladislav



--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@...> wrote:

>

> Ladislav, don't blame Ray for something he can't do. He doesn't own

> a Gemini mount and has no hands-on experience with one (at least

I'm

> pretty sure he doesn't). I'm not sure why you'd expect him to give

> you instructions on how to adjust something he has no experience

> with.

>

> Neither is Doc Goerlich to blame, as the problem is not with

Gemini.

> And believe me, not every G11 has this non-periodic error: mine has

> a total PE (without PEC) of under 4 arcseconds, with only about 1

> arcsec of non-periodic error which I attributed to the Oldham

> coupler.

>

> Adjusting your mount properly is important. Search the archives for

> worm/motor-shaft alignment instructions. This is critical -- there

> should be a straight line between the motor shaft and the worm.

Make

> sure the worm blocks are straight and the worm bearings not twisted

> in the worm blocks, even by a tiny amount.

>

> Don't forget: you have two complete worm assemblies on the mount,

PE

> is important only in RA. Swap the motors, swap the gear boxes, swap

> the worms and even the worm blocks between DEC and RA, and check

> again with PEMPro. You may find a much lower PE and a lower or non-

> existent 76-sec periodic component.

>

> Regards,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "nemecll" nemecl@> wrote:

> >

> > Pity I did not join the group earlier. Hardware problems belong

> here

> > rather than on the Gemini group.

> >

> > I wasted tremendous amount of time with Pempro trying to optimize

> my

> > PEC (some 15 plus arcsecs peak to peak). No matter what I did, it

> > made no difference whatever. Autoguiding with an SBIG camera

works

> > but this is NOT the solution for PE. I bought my G11 about a year

> > ago based on the specs that talk enthusiastically about the PEC

> > functionality, especially with Gemini. During the testing of

> Gemini

> > L4 I reported and documented problems with my PEC only to be

> > dismissed by people in that group and ignored by the Goerlichs

> > (authors of Gemini and Gemini Control Center software).

> >

> > The lack of communication between Scott Losmandy and the

Goerlichs

> > (in Germany) is amazing. Nowhere during the testing of Gemini the

> > problem with the non-periodic (i.e., not related to the period of

> > the worm) problem was mentioned. Rene Goerlich has a Losmandy

> mount

> > but he is a programmer first, mechanic last...

> >

> > I am really upset by this situation. A few hours ago Ray Gralak

> > wrote

> > me to do my own research how to fix the problem he identified as

> > lack of centering of the Oldham coupler, whatever that means. One

> > would expect that he would provide more help since I am not going

> to

> > spend $150 for Pempro (fortunately now in my 60 day trial period)

> if

> > it is NOT going to work.

> >

> > Scott Losmandy is currently not available but he is supposed to

> be

> > back by September 8. I sent him a private mail, bit strong for

his

> > taste, perhaps. I prefer not to communicate with manufacturers, I

> > expect their equipment to work. Well, I should have known better

a

> > year ago before I spent my $3,500 for the mount (including CA

> > taxes).

> >

> > Any comment and, most importantly, instructions how to fix this

> > problem (if it is fixable) will be greatly appreciated through

> this

> > forum or privately.

> >

> > Ladislav Nemec

> > Big Bear, CA

> > Minor Planet Center 'observatory' G77, Baldwin Lake

> >

> > nemecl@

> >

>







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

#30749 Sep 6, 2006

Ladislav,



The root cause of the 76 sec oscillation is (IMHO) not due to Oldham

coupler alignment. Coupler misalignment may increase the amplitude of

this cycle but by itself does not generate it. The coupler has even

symmetry, defects should tend to show up as primarily Peroid/2 or /4

cycles, 76 sec does not divide into 240 sec as you well know. I believe

the problem is caused by the ball bearings holding the worm, they are

pinched by the bearing block. This hypothesis is supported by data I

took during my G11 tuning odyssey.



I have graphs showing the tracking error for runs with the coupler

intentionally misaligned, no 78sec component is visible. The

misalignment seems to cause the tracking to be more erratic, which makes

sense since the coupler is working hard bending and sliding all over the

places causing random jumps.



I tried Mike S.'s fix of reeming out the slot in the nylon center piece

of the coupler. No help. Tried a helical coupler, no better. Finally

enlarging the ball bearing pockets in the worm blocks did the trick.

Others have reported that filing off the bottom of the worm blocks works

just as well (and is probably easier to do). If your tracking error

look like this:

www.freewebs.com/ebenson/G11%20Tracking/PemPro-2006-04-09-223103.\

png

www.freewebs.com/ebenson/G11%20Tracking/PemPro-2006-04-09-223103\

.png>

then suspect a pinched block. see the rest of the saga here:

www.freewebs.com/ebenson/g11tracking.htm

www.freewebs.com/ebenson/g11tracking.htm>



BTW the range of feelings you describe (Shock/Denial/Anger...) should

have it's own name (G11 grief cycle!?!). It seems a lot of us with

problamatic G11's went through the same thing. Hope you get to

acceptance fast! ;)



EB



--- In Losmandy_users@yahoogroups.com, "nemecll" nemecl@...> wrote:

>

> Paul,

> you are, as almost alwyas, right. No matter what the cause of this 77

> second 'periodic error' is, it is a HARDWARE not software problem (in

> either Rene's Gemini code or Ray's Pempro). It has bee very

> unproductive on my part to become kind of 'emotional' and blame

> anyone - this is just one of the things amateurs with limited means

> have to cope with.

>

> I was briefly considering to spend some $12,000 for Software Bisque

> Paramount but I dismissed the idea as not appropriate to my financial

> situation. Who knows, even that mount may have its glitches...

>

> Recently I 'played' with the RA worm assembly and for no apparent

> reason the RA jumps and humps were diminished. Now I know what to

> look for and this is the first and fairly easy step. If I succeed

> I'll try to describe my 'procedure' in some detail here.

>

> I am not worred about the DEC assembly - except for tracking unusual

> objects continuous DEC motion is not needed. Bad DEC motion can of

> course affect the autoguiding. In any case, first things first.

>

> Going back to Gemini. I actually detected the problem months ago and

> I reported it on the Gemini L4 group without having any idea what the

> problem was. Simply: my tracking WITH PEC was worse than without it.

> At that time I attributed it to some glitches in the Gemini code

> still under development. It was dismissed by the group and by Rene -

> interestingly enough, as far as I remember, nobody mentioned the

> Oldham coupler (or other hardware glitch) as a possible reason for my

> then 'inexplicable' results. Since then very similar experiences was

> reported on the CCDWare users group - I did not read all the messages

> but one was just like my own 'Worse with PEC than without it'.

>

> It is satisfying to confirm my results months back - the science (?)

> of G11 is making slow but sure progress and we all (first of all I)

> should stop being emotional...

>

> Regards, Ladislav

>

>

> --- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@ wrote:

> >

> > Ladislav, don't blame Ray for something he can't do. He doesn't own

> > a Gemini mount and has no hands-on experience with one (at least

> I'm

> > pretty sure he doesn't). I'm not sure why you'd expect him to give

> > you instructions on how to adjust something he has no experience

> > with.

> >

> > Neither is Doc Goerlich to blame, as the problem is not with

> Gemini.

> > And believe me, not every G11 has this non-periodic error: mine has

> > a total PE (without PEC) of under 4 arcseconds, with only about 1

> > arcsec of non-periodic error which I attributed to the Oldham

> > coupler.

> >

> > Adjusting your mount properly is important. Search the archives for

> > worm/motor-shaft alignment instructions. This is critical -- there

> > should be a straight line between the motor shaft and the worm.

> Make

> > sure the worm blocks are straight and the worm bearings not twisted

> > in the worm blocks, even by a tiny amount.

> >

> > Don't forget: you have two complete worm assemblies on the mount,

> PE

> > is important only in RA. Swap the motors, swap the gear boxes, swap

> > the worms and even the worm blocks between DEC and RA, and check

> > again with PEMPro. You may find a much lower PE and a lower or non-

> > existent 76-sec periodic component.

> >

> > Regards,

> >

> > -Paul

> >

> > --- In Losmandy_users@yahoogroups.com, "nemecll" nemecl@> wrote:

> > >

> > > Pity I did not join the group earlier. Hardware problems belong

> > here

> > > rather than on the Gemini group.

> > >

> > > I wasted tremendous amount of time with Pempro trying to optimize

> > my

> > > PEC (some 15 plus arcsecs peak to peak). No matter what I did, it

> > > made no difference whatever. Autoguiding with an SBIG camera

> works

> > > but this is NOT the solution for PE. I bought my G11 about a year

> > > ago based on the specs that talk enthusiastically about the PEC

> > > functionality, especially with Gemini. During the testing of

> > Gemini

> > > L4 I reported and documented problems with my PEC only to be

> > > dismissed by people in that group and ignored by the Goerlichs

> > > (authors of Gemini and Gemini Control Center software).

> > >

> > > The lack of communication between Scott Losmandy and the

> Goerlichs

> > > (in Germany) is amazing. Nowhere during the testing of Gemini the

> > > problem with the non-periodic (i.e., not related to the period of

> > > the worm) problem was mentioned. Rene Goerlich has a Losmandy

> > mount

> > > but he is a programmer first, mechanic last...

> > >

> > > I am really upset by this situation. A few hours ago Ray Gralak

> > > wrote

> > > me to do my own research how to fix the problem he identified as

> > > lack of centering of the Oldham coupler, whatever that means. One

> > > would expect that he would provide more help since I am not going

> > to

> > > spend $150 for Pempro (fortunately now in my 60 day trial period)

> > if

> > > it is NOT going to work.

> > >

> > > Scott Losmandy is currently not available but he is supposed to

> > be

> > > back by September 8. I sent him a private mail, bit strong for

> his

> > > taste, perhaps. I prefer not to communicate with manufacturers, I

> > > expect their equipment to work. Well, I should have known better

> a

> > > year ago before I spent my $3,500 for the mount (including CA

> > > taxes).

> > >

> > > Any comment and, most importantly, instructions how to fix this

> > > problem (if it is fixable) will be greatly appreciated through

> > this

> > > forum or privately.

> > >

> > > Ladislav Nemec

> > > Big Bear, CA

> > > Minor Planet Center 'observatory' G77, Baldwin Lake

> > >

> > > nemecl@

> > >

> >

>









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







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

#30751 Sep 6, 2006

I appreciate your advice and sense of humor. There are 5 stages (?) of

grief? And it is a 'process', as the shrink in 'Analyze That' used to say.

Hopefully, the G11 angst (for lack of a better word) is a less serious

phenomenon.







I just posted my little treatise on the sources of errors and it seems that

blaming the Oldham coupling is not quite fair - as Paul writes,



It is not designed to handle two moving axes at different angles, only

non-collateral axes. Instead of filing the bottom of one or both bearing

blocks, thin 'shins' may do the job bit more easily. I think such shins are

available although I am not sure where.







Let's google shins against G11 angst! If Google is any good, it should

retrieve this message.







I will look at the images of your link but I am most anxious to see what my

actions improved, made worse or had no effect. It seems that each G11 is a

slightly different animal although they all are supposed to be identical

twins or clones.







Best, LN







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

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

On Behalf Of Eric Benson

Sent: Wednesday, September 06, 2006 3:46 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: PEC and oldham coupler









Ladislav,



The root cause of the 76 sec oscillation is (IMHO) not due to Oldham

coupler alignment. Coupler misalignment may increase the amplitude of

this cycle but by itself does not generate it. The coupler has even

symmetry, defects should tend to show up as primarily Peroid/2 or /4

cycles, 76 sec does not divide into 240 sec as you well know. I believe

the problem is caused by the ball bearings holding the worm, they are

pinched by the bearing block. This hypothesis is supported by data I

took during my G11 tuning odyssey.



I have graphs showing the tracking error for runs with the coupler

intentionally misaligned, no 78sec component is visible. The

misalignment seems to cause the tracking to be more erratic, which makes

sense since the coupler is working hard bending and sliding all over the

places causing random jumps.



I tried Mike S.'s fix of reeming out the slot in the nylon center piece

of the coupler. No help. Tried a helical coupler, no better. Finally

enlarging the ball bearing pockets in the worm blocks did the trick.

Others have reported that filing off the bottom of the worm blocks works

just as well (and is probably easier to do). If your tracking error

look like this:

www.freewebs

www.freewebs.com/ebenson/G11%20Tracking/PemPro-2006-04-09-223103.png > .com/ebenson/G11%20Tracking/PemPro-2006-04-09-223103.\

png

www.freewebs

www.freewebs.com/ebenson/G11%20Tracking/PemPro-2006-04-09-223103.png > .com/ebenson/G11%20Tracking/PemPro-2006-04-09-223103\

.png>

then suspect a pinched block. see the rest of the saga here:

www.freewebs www.freewebs.com/ebenson/g11tracking.htm>

.com/ebenson/g11tracking.htm

www.freewebs www.freewebs.com/ebenson/g11tracking.htm>

.com/ebenson/g11tracking.htm>



BTW the range of feelings you describe (Shock/Denial/Anger...) should

have it's own name (G11 grief cycle!?!). It seems a lot of us with

problamatic G11's went through the same thing. Hope you get to

acceptance fast! ;)



EB



--- In Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

yahoogroups.com, "nemecll" nemecl@...> wrote: >

> Paul,

> you are, as almost alwyas, right. No matter what the cause of this 77

> second 'periodic error' is, it is a HARDWARE not software problem (in

> either Rene's Gemini code or Ray's Pempro). It has bee very

> unproductive on my part to become kind of 'emotional' and blame

> anyone - this is just one of the things amateurs with limited means

> have to cope with.

>

> I was briefly considering to spend some $12,000 for Software Bisque

> Paramount but I dismissed the idea as not appropriate to my financial

> situation. Who knows, even that mount may have its glitches...

>

> Recently I 'played' with the RA worm assembly and for no apparent

> reason the RA jumps and humps were diminished. Now I know what to

> look for and this is the first and fairly easy step. If I succeed

> I'll try to describe my 'procedure' in some detail here.

>

> I am not worred about the DEC assembly - except for tracking unusual

> objects continuous DEC motion is not needed. Bad DEC motion can of

> course affect the autoguiding. In any case, first things first.

>

> Going back to Gemini. I actually detected the problem months ago and

> I reported it on the Gemini L4 group without having any idea what the

> problem was. Simply: my tracking WITH PEC was worse than without it.

> At that time I attributed it to some glitches in the Gemini code

> still under development. It was dismissed by the group and by Rene -

> interestingly enough, as far as I remember, nobody mentioned the

> Oldham coupler (or other hardware glitch) as a possible reason for my

> then 'inexplicable' results. Since then very similar experiences was

> reported on the CCDWare users group - I did not read all the messages

> but one was just like my own 'Worse with PEC than without it'.

>

> It is satisfying to confirm my results months back - the science (?)

> of G11 is making slow but sure progress and we all (first of all I)

> should stop being emotional...

>

> Regards, Ladislav

>

>

> --- In Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

yahoogroups.com, "Paul K" pkane2001@ wrote: > >

> > Ladislav, don't blame Ray for something he can't do. He doesn't own

> > a Gemini mount and has no hands-on experience with one (at least

> I'm

> > pretty sure he doesn't). I'm not sure why you'd expect him to give

> > you instructions on how to adjust something he has no experience

> > with.

> >

> > Neither is Doc Goerlich to blame, as the problem is not with

> Gemini.

> > And believe me, not every G11 has this non-periodic error: mine has

> > a total PE (without PEC) of under 4 arcseconds, with only about 1

> > arcsec of non-periodic error which I attributed to the Oldham

> > coupler.

> >

> > Adjusting your mount properly is important. Search the archives for

> > worm/motor-shaft alignment instructions. This is critical -- there

> > should be a straight line between the motor shaft and the worm.

> Make

> > sure the worm blocks are straight and the worm bearings not twisted

> > in the worm blocks, even by a tiny amount.

> >

> > Don't forget: you have two complete worm assemblies on the mount,

> PE

> > is important only in RA. Swap the motors, swap the gear boxes, swap

> > the worms and even the worm blocks between DEC and RA, and check

> > again with PEMPro. You may find a much lower PE and a lower or non-

> > existent 76-sec periodic component.

> >

> > Regards,

> >

> > -Paul

> >

> > --- In Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

yahoogroups.com, "nemecll" nemecl@> wrote: > > >

> > > Pity I did not join the group earlier. Hardware problems belong

> > here

> > > rather than on the Gemini group.

> > >

> > > I wasted tremendous amount of time with Pempro trying to optimize

> > my

> > > PEC (some 15 plus arcsecs peak to peak). No matter what I did, it

> > > made no difference whatever. Autoguiding with an SBIG camera

> works

> > > but this is NOT the solution for PE. I bought my G11 about a year

> > > ago based on the specs that talk enthusiastically about the PEC

> > > functionality, especially with Gemini. During the testing of

> > Gemini

> > > L4 I reported and documented problems with my PEC only to be

> > > dismissed by people in that group and ignored by the Goerlichs

> > > (authors of Gemini and Gemini Control Center software).

> > >

> > > The lack of communication between Scott Losmandy and the

> Goerlichs

> > > (in Germany) is amazing. Nowhere during the testing of Gemini the

> > > problem with the non-periodic (i.e., not related to the period of

> > > the worm) problem was mentioned. Rene Goerlich has a Losmandy

> > mount

> > > but he is a programmer first, mechanic last...

> > >

> > > I am really upset by this situation. A few hours ago Ray Gralak

> > > wrote

> > > me to do my own research how to fix the problem he identified as

> > > lack of centering of the Oldham coupler, whatever that means. One

> > > would expect that he would provide more help since I am not going

> > to

> > > spend $150 for Pempro (fortunately now in my 60 day trial period)

> > if

> > > it is NOT going to work.

> > >

> > > Scott Losmandy is currently not available but he is supposed to

> > be

> > > back by September 8. I sent him a private mail, bit strong for

> his

> > > taste, perhaps. I prefer not to communicate with manufacturers, I

> > > expect their equipment to work. Well, I should have known better

> a

> > > year ago before I spent my $3,500 for the mount (including CA

> > > taxes).

> > >

> > > Any comment and, most importantly, instructions how to fix this

> > > problem (if it is fixable) will be greatly appreciated through

> > this

> > > forum or privately.

> > >

> > > Ladislav Nemec

> > > Big Bear, CA

> > > Minor Planet Center 'observatory' G77, Baldwin Lake

> > >

> > > nemecl@

> > >

> >

>



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











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







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

#30755 Sep 6, 2006

Many thanks. Very encouraging.

LN







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

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

On Behalf Of Mike Siniscalchi

Sent: Wednesday, September 06, 2006 6:52 AM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: PEC and oldham coupler







Hello Ladislav,



I know your frustrations when it comes to spending $$$$ on a mount

and having to do some work to get it to where you can use it for your

intended use. I am not saying that mounts don't need tweaking

however, but they should not have to be repaired to get them to work

out of the box (more info on that can be found at

www.helixgat www.helixgate.net/g11.html> e.net/g11.html ).

Having experience in mechanics

myself I was able to repair my new G11's fairly random PE camel type

humps (on each side of the sinusoidal curve) as well as a few other

issues without sending the parts back and waiting. I addressed the

issue with the tight and mis-aligned Oldham coupler easily and it

totally eliminated the sudden PE humps, most probably due to friction

loading and un-loading, with a simple use of a Dremel bit to hone the

bore opening in the nylon coupler. Please refer to message ID # 27966

for the details.

Personally I thing the Oldham coupler design is not the best for a

mount used for imaging but with a little work can be made to perform

well.

I can answer any question either public or private.



Best Regards,

Mike Siniscalchi



www.helixgat www.helixgate.net> e.net



--- In Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

yahoogroups.com, "nemecll" nemecl@...> wrote: >

> Pity I did not join the group earlier. Hardware problems belong

here > rather than on the Gemini group.

>

> I wasted tremendous amount of time with Pempro trying to optimize

my > PEC (some 15 plus arcsecs peak to peak). No matter what I did, it

> made no difference whatever. Autoguiding with an SBIG camera works

> but this is NOT the solution for PE. I bought my G11 about a year

> ago based on the specs that talk enthusiastically about the PEC

> functionality, especially with Gemini. During the testing of Gemini

> L4 I reported and documented problems with my PEC only to be

> dismissed by people in that group and ignored by the Goerlichs

> (authors of Gemini and Gemini Control Center software).

>

> The lack of communication between Scott Losmandy and the Goerlichs

> (in Germany) is amazing. Nowhere during the testing of Gemini the

> problem with the non-periodic (i.e., not related to the period of

> the worm) problem was mentioned. Rene Goerlich has a Losmandy mount

> but he is a programmer first, mechanic last...

>

> I am really upset by this situation. A few hours ago Ray Gralak

> wrote

> me to do my own research how to fix the problem he identified as

> lack of centering of the Oldham coupler, whatever that means. One

> would expect that he would provide more help since I am not going

to > spend $150 for Pempro (fortunately now in my 60 day trial period)

if > it is NOT going to work.

>

> Scott Losmandy is currently not available but he is supposed to be

> back by September 8. I sent him a private mail, bit strong for his

> taste, perhaps. I prefer not to communicate with manufacturers, I

> expect their equipment to work. Well, I should have known better a

> year ago before I spent my $3,500 for the mount (including CA

> taxes).

>

> Any comment and, most importantly, instructions how to fix this

> problem (if it is fixable) will be greatly appreciated through

this > forum or privately.

>

> Ladislav Nemec

> Big Bear, CA

> Minor Planet Center 'observatory' G77, Baldwin Lake

>

> nemecl@...

>











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



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