I dunno Chip, maybe it's just my mount. ?But it is horrible cranked tight. ?So horrible that imaging isn't possible. ?It basically turns that beautiful mount into a visual only mount. ?
At this point I'm not too concerned because it's just plain working now so I'm happy. ?
BTW, your arc-sec rms is super good. ?I hope to get mine there in time. ?Still getting used to using it.
-Rich-
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Michael, my new G11G doesn't have that upper bellevue wavy washer. ?My problem was the thrust bearing down by the clutch knob. ?If it gets squeezed too tightly it makes the RA rough. ?Kinda like a wheel bearing on a car that is tightened too tight.
-Rich-
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Re: File - Guidance on Posting Documents and Pictures.doc
You have to do it yourself. Here's the link.
losmandy_users-unsubscribe@...
Don
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----- Original Message ----- From: "'George Seitz' gwsarch@... [Losmandy_users]" <Losmandy_users@...> To: <Losmandy_users@...> Sent: Wednesday, November 01, 2017 4:04 PM Subject: RE: [Losmandy_users] File - Guidance on Posting Documents and Pictures.doc Please delete me from your email.
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The open design of the Losmandy drive system makes working on it rather easy. But it leaves open the potential for airborne dust or grit to get in there and wreck havoc with the operation.?? That is just our nightmares on a clear moonless windless night... ready to image when a drive glitch appears.
I hope you sort out the trouble.? So far, I have not got that particular trouble... (did I say... so far?)
- Best? Michael?
On Wed, Nov 1, 2017 at 1:56 PM, tazercn@... [Losmandy_users] <Losmandy_users@...> wrote:
?
Michael, my issue may be different than Rich's but what I'm experiencing seems like a bearing popping and some slight stiction/backlash afterwards where PHD has trouble getting RA back to the center line. Once it does it stays there nicely until it pops again. Mine's only about 2" (I'm imaging at ~0.5" ppx using an OAG) so it looks like seeing but it only happens in one direction.
Figured the stiction/backlash might be due to the Belleville washer I installed a while back (before I increased the payload) so I removed it and saw the same behavior.
Read a bit about removing backlash with the original opwb and I had been doing it by loosening one bearing block only. I figured it might be 'twisting' the bearings causing something like the old 76s error. So I took care to loosen/tighten both blocks together when adjusting backlash. Still I see the same behavior.
Next I suspected it could be related to the Oldham, so I carefully aligned the gearbox-oldham-worm axis so that it would all spin freely before installing the servo. Same behavior.
I had been thinking it was potentially grit or damage in the gearbox and was planning on replacing it with a brand new spare I have in the closet.
I was also considering putting the old bearing back in, I had upgraded to ABEC7's when I put in the Belleville washer, in case one of the new ones were damaged somehow.
I'll do the clutch test soon and see if that has any effect. I'll start off with it tight (like normal) and then incrementally back off on it until the scope starts slipping.
If that doesn't work I'll do the bearings and gearbox swap at the same time.
Mark
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Michael, my issue may be different than Rich's but what I'm experiencing seems like a bearing popping and some slight stiction/backlash afterwards where PHD has trouble getting RA back to the center line. Once it does it stays there nicely until it pops again. Mine's only about 2" (I'm imaging at ~0.5" ppx using an OAG) so it looks like seeing but it only happens in one direction.
Figured the stiction/backlash might be due to the Belleville washer I installed a while back (before I increased the payload) so I removed it and saw the same behavior.
Read a bit about removing backlash with the original opwb and I had been doing it by loosening one bearing block only. I figured it might be 'twisting' the bearings causing something like the old 76s error. So I took care to loosen/tighten both blocks together when adjusting backlash. Still I see the same behavior.
Next I suspected it could be related to the Oldham, so I carefully aligned the gearbox-oldham-worm axis so that it would all spin freely before installing the servo. Same behavior.
I had been thinking it was potentially grit or damage in the gearbox and was planning on replacing it with a brand new spare I have in the closet.
I was also considering putting the old bearing back in, I had upgraded to ABEC7's when I put in the Belleville washer, in case one of the new ones were damaged somehow.
I'll do the clutch test soon and see if that has any effect. I'll start off with it tight (like normal) and then incrementally back off on it until the scope starts slipping.
If that doesn't work I'll do the bearings and gearbox swap at the same time.
Mark
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Rich,
That sounds odd to me. When I got my updated G11 to a G11G and tested it I cranked the clutches down as usual and saw no measured changes in tracking error. I have always cranked the clutches down pretty firmly for Gemini use and imaging with very good results. Maybe I should try retesting with the clutches set looser than normal to see if the PE improves though it seems unlikely as my PE is already low when unguided and guided my G11G is 034-0.41 arcsecond range which seems good enough.?I also have tested the current draw using a precision bench power supply and there is zero difference in current draw duty cycle and lag rates when cranked down super tight and loose enough to use in PUSH-TO mode. This is on a Losmandy G11 Scott had retrofitted as fully optioned G11G spec mount with w/Gemini 2-mini and high torque servo motors.?
Chip
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Re: File - Guidance on Posting Documents and Pictures.doc
Please delete me from your email. ?
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From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Wednesday, November 01, 2017 9:01 AM
To: Losmandy_users@...
Subject: RE: [Losmandy_users] File - Guidance on Posting Documents and Pictures.doc? ? Please delete me from your email. ? ? ?
File : Guidance on Posting Documents and Pictures.doc
Description : A few rules and comments to prevent anarchy in the files and photos section
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That's unfortunate and I don't find that clutch effect on worm gear to ring gear spacing on the old CG11 that I have, or the newer GM8.??
I wonder if it has to do with the extra new Belleville spring washer I think they installed in the newer systems.? Nothing should affect the worm as the ring gear only rides on the upper flat needle bearing system.? That is not affected by the clutch...or it should not be if the ring gear surface is flat and perpendicukar tobthe axis and parallel to the upper driven plate (Are they?)
Only you can run this experiment: see if that spring washer is in there and remove it.? You shouldn't need it anyway...it was installed to make the axis move more freely for scope balance.? Would your worm gear behavior work better (no effect of clutch knob) if the spring is removed?
Anyway, its an unwelcome puzzle to figure out.??
best, Michael?
On Nov 1, 2017 12:29 PM, " sornborger@... [Losmandy_users]" < Losmandy_users@...> wrote:
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Hope it works for you too Mark.? I can't believe the difference it has made on this mount.? For 11 days I've been struggling with this new mount and all I had to do was back off the clutch knob.? Unbelievable.
-Rich-
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Hope it works for you too Mark. ?I can't believe the difference it has made on this mount. ?For 11 days I've been struggling with this new mount and all I had to do was back off the clutch knob. ?Unbelievable.
-Rich-
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Glad you figured it out. I'm actually experiencing something similar where I'm getting 2-3" spikes in RA consistently while my DEC guiding is very solid (1-2" RMS in RA, .3-.4" in DEC). I haven't measured the spike period but 30-40 seconds sounds about right.
My only semi-recent change was putting a larger scope on, so I'm running about 40lbs of gear. Since I use the system visually, I tend to crank down on the clutches to prevent the scope from moving when I change eyepieces (heavy ones anyway). I bet I've got the clutches way too tight.
I'll chime in with my results as well when I get a chance to setup again.
Thanks again for sharing your experiences and solutions.
Mark
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Re: File - Guidance on Posting Documents and Pictures.doc
You have to go to Losmandy Yahoo Groups and delete yourself.
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On 11/1/2017 12:01 PM, 'George Seitz' gwsarch@... [Losmandy_users] wrote: Please delete me from your email.
*From:*Losmandy_users@... [mailto:Losmandy_users@...]
*Sent:* Tuesday, October 31, 2017 8:23 PM
*To:* Losmandy_users@...
*Subject:* [Losmandy_users] File - Guidance on Posting Documents and Pictures.doc
File : Guidance on Posting Documents and Pictures.doc
Description : A few rules and comments to prevent anarchy in the files and photos section
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Re: File - Guidance on Posting Documents and Pictures.doc
Please delete me from your email. ?
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From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Tuesday, October 31, 2017 8:23 PM
To: Losmandy_users@...
Subject: [Losmandy_users] File - Guidance on Posting Documents and Pictures.doc? ?
File : Guidance on Posting Documents and Pictures.doc
Description : A few rules and comments to prevent anarchy in the files and photos section
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File - Guidance on Posting Documents and Pictures.doc
File : Guidance on Posting Documents and Pictures.doc
Description : A few rules and comments to prevent anarchy in the files and photos section
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That sounds like good progress ;) ? ? Brian ? ? Brian Valente Brianvalentephotography.com ?
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From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Tuesday, October 31, 2017 7:35 PM
To: Losmandy_users@...
Subject: [Losmandy_users] Re: G11G RA Clutch? ? Ok, I've found out that on my mount tightening that clutch screw tight does indeed ruin auto guiding. ?Backed off half a turn has turned my guiding into .5 RA guiding without those huge spikes. So the little flat thrust bearing hates to be squeezed too tight. ?It protests.
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Ok, I've found out that on my mount tightening that clutch screw tight does indeed ruin auto guiding. ?Backed off half a turn has turned my guiding into .5 RA guiding without those huge spikes.
So the little flat thrust bearing hates to be squeezed too tight. ?It protests.
-Rich-
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I feel better now, Brian! 5 arcsec I can believe.??
All the best, Michael?
On Oct 31, 2017 1:56 PM, "'Brian Valente' bvalente@... [Losmandy_users]" < Losmandy_users@...> wrote:
?
Eric you are correct, my bad. I thought we were talking G11GT ? I¡¯ll have to revisit my comments ? My G11G does not have the 40 second periodic error, so ignore that (I should also clarify I meant 40 second periodicity, the actual error is something like 2.4arcsecs. wow I¡¯m in rare form today) ? SO on my G11G - My experience of getting the tucked in gearing added to my G11G and getting it back sounds the same as Chip¡¯s - the RA performance was basically identical. I think unguided it¡¯s around +/- 5 arcsec ? Rich, Regarding the RA clutch disk, I could have sworn Losmandy switched to a new better clutch system than the plastic ones, or at least they have it as an upgrade, you might call them and ask. ? ? Sorry again folks ¨C messed up my terminology. I¡¯m not used to this renaming of the old mounts. ? I¡¯ll crawl back in my cave now ;) ? Thanks ? Brian ? ? Brian Valente Brianvalentephotography.com ? ? ? According to the Losmandy website the G11G is just a G11 with goto. The G11GT the the G11 DEC and Titan RA. ? ? Guys ? Just to clarify, are we talking a G11 or a G11G? ? The G11G is the Titan RA with G11 DEC ? The RA portion has nothing to do with the regular G11 RA axis ? I¡¯m confused now, but again, I am here in LA and have both G11 and G11G. I currently have my G11G setup, G11 is semi-retired sitting on the table. ? ? ? Thanks ? Brian ? ? Brian Valente
? ? ?? Hi Rich, Where are you located??I'm sure there is somebody near you that has a G11 that can help if you live near a city or large town. I'm in L.A., Michael Herman is up in bay area. I'm sure people are willing to help near you, they just need to know they are needed. Don't get me wrong, I used to mess with mine all the time but when I got my updated G11G back from Scott I wanted to test it as delivered and to see if the mount's PE had changed. When I tested it the tracking error was virtually identical to my modified and carefully adjusted 2-piece worn block and HP worms before I drove over the G11 over to Scott's shop. I'm a car guy and I love working with all things mechanical, I enjoyed playing with the G11 so much I bought a GM8 to play with. Well sort of anyway, I also needed a lightweight mount for wheelie bar driveway duty and the SkyView-Pro was very scarily overloaded at the time with my P/AT130mm f/6 APO and M10" f/6.3 SCT OTA both optically outstanding scopes that I did not want to risk on a mount rated for a 15 lb payload.?
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I am ¨C I forgot that! ? But no, I wasn¡¯t there, sorry ? Thanks ? Brian ? ? Brian Valente Brianvalentephotography.com ?
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From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Tuesday, October 31, 2017 4:09 PM
To: Losmandy_users@...
Subject: [Losmandy_users] Re: G11G RA Clutch? ? Hi Brian, I think you're an LAAS member. Were you at Mt Wilson a few weeks ago??
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Hi Brian,
I think you're an LAAS member. Were you at Mt Wilson a few weeks ago??
Chip
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At 21:56 31-10-17, 'Brian Valente' bvalente@... [Losmandy_users] wrote: Rich, Regarding the RA clutch disk, I could have sworn Losmandy switched to a new better clutch system than the plastic ones, or at least they have it as an upgrade, you might call them and ask. Apparently this happened c. 2015. See: David
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Rick,
Another link that seems to speak to your problem:
David
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Michael Herman