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Re: RA guiding awful after upgrade
开云体育Y’all are leaving out the NEW pier extension.. .. You installed BOTH a new RA eXT *and* a 12” pier extension, right?? My suggestion would be to take the fully loaded setup and loosen and retighten all the fasteners (used to install the extension to your mount, not any fasteners used to assemble the extension itself..).. Do the same with the RA EXT.. I have the RA EXT, and no pier extension and never had this issue.. To me it’s the pier extension.. ? My second suggestion would be balance is not as east heavy as you think it is, which is why it doesn’t work on one side but not the other.. ? Something else.. You didn’t mention the weather.. has it been obviously colder than when it work well?? How much does the bottom end of the counterweight shaft move when you try and move it with your hand?? I have other *simple* suggestions before you do anything drastic.. ? Derek ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Chip Louie
via groups.io
Sent: Thursday, January 30, 2025 4:30 PM To: [email protected] Subject: Re: [Losmandy_users_io] RA guiding awful after upgrade ? On Wed, Jan 29, 2025 at 05:58 PM, Thomas Kallenbach wrote:
? To follow up on my previous post Losmandy is an outstanding company in that the people really do their best to support the Losmandy community.? Losmandy fully, and I mean FULLY supports every mount new and used they have ever produced including the Celestron branded mounts.? I mean nobody, NOBODY will take a mount in they made 30+ years ago and rebuild it to the current specs for that mount no matter how fancy the brand is considered today.? Sure it's not free but you cannot get this from any other mount maker in the normal course of business period.??Losmandy knows the value of their mounts, it just goes to show you what all the other telescope mount makers think of their work and your investment.? ? ? All it takes is money on your part.? Does it always make economic sense?? In my experience no,? but it can be done for those mounts with a special attachment or special history.? I've done it and IME it was well worth the additional cost when it was all said and done.? But also I think I need to say that unless you bought the mount for peanuts it will not really be time or cost effective to have the old mount updated to current specs.? At least you already have a Gemini (2??) so that makes it closer to cost effective.?? ? I will say that as an owner of several G11 and GM8 mounts as well as my original 20+ YO G11"s" model that over a few years I upgraded through the full 30+ year progression from the original model G11s PUSH-TO #492 Digital Drive mount which I fully disassembled to rebuild and lube the internal bearings, then installing High Precision worms, aligning the gearbox output shaft so the Oldham coupler connection to the worm was as straight as possible, modifying the bearing blocks to encourage full worm bearing rotation and remove worm endplay using Belleville springs, adding a new modern era double clamp 8" Losmandy dual D/V saddle, experimentally making a one piece worm block with Belleville springs to use the bearings to preload the worms (this worked very well so I told Scott about it who then showed me what he was working on in secret which caused me to wait for over a year for the coming Losmandy spring loaded OPW) installing a Gemini 1 controller, building a regulated multi-voltage (13.5v & 17.5v) multi-bank power pack to support portable field use for visual and imaging work for 2 Losmandy Gemini mounts, installing a Gemini 2 system and then having Scott do the full update to the new OPWs, RA extension etc. then at a later date once finalized Scott added the spring loaded feature.? It has been a journey but what fun we had!? So was it worth it?? As I said for me it most certainly was.?? ? To answer the ASIAIR question it has been my experience that the ASIAIR is not quite as good at autoguiding as using a laptop and PHD2 on the same mount and imaging rig.? I say this because I relied on ASCOM and PHD2 and SGP for imaging and 5 years ago PHD2 produced excellent guiding on the same 20+ YO mount using the same guide scope and ASI120MM mini and ASI290MM mini.? The numbers are just not as good in absolute terms but what I have seen is that if you are guiding well under 0.5" total error and then the ASIAIR comes along and is guiding at 0.7" total error and I cannot see any advantage to putting up with all the extra trouble of using a laptop and a dozen cables to make it work I'm just not going to bother.? Give me the elegance of the ASIAIR solution anyday. ? Here is the small driveway imaging rig clamped to an old school Losmandy S-B-S dovetail on the even older G11G, LWT and Wheelie Bar.? The small imaging rig is an Askar FRA500 90mm f.5.6 Petzval working @ f/3.9, ASIAIR Plus 256GB v3, ASI2600MC-Pro main camera, EFW 2"x5, EFA w/temp probe, ASI678MM guide camera on Stellarvue 50mm f/4 guide scope, Deep Sky Dad Flat Panel and a Stellarvue 50mm visual finder.? Waiting for the CAA to show up, should be any day now LOL.? All of the components and most cables are on the scope and move with the scope except for 2 independent power cords and an Ethernet cord.? The ASIAIR Plus and Gemini 2 talk to each other through a high performance Slate AX1800 travel router via Ethernet and the tablet or phone use the Slate to connect over Wi-Fi.? ? ? ? ? ? ? ? --
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Re: RA guiding awful after upgrade
On Wed, Jan 29, 2025 at 05:58 PM, Thomas Kallenbach wrote:
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To follow up on my previous post Losmandy is an outstanding company in that the people really do their best to support the Losmandy community.? Losmandy fully, and I mean FULLY supports every mount new and used they have ever produced including the Celestron branded mounts.? I mean nobody, NOBODY will take a mount in they made 30+ years ago and rebuild it to the current specs for that mount no matter how fancy the brand is considered today.? Sure it's not free but you cannot get this from any other mount maker in the normal course of business period.??Losmandy knows the value of their mounts, it just goes to show you what all the other telescope mount makers think of their work and your investment.? ?
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All it takes is money on your part.? Does it always make economic sense?? In my experience no,? but it can be done for those mounts with a special attachment or special history.? I've done it and IME it was well worth the additional cost when it was all said and done.? But also I think I need to say that unless you bought the mount for peanuts it will not really be time or cost effective to have the old mount updated to current specs.? At least you already have a Gemini (2??) so that makes it closer to cost effective.??
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I will say that as an owner of several G11 and GM8 mounts as well as my original 20+ YO G11"s" model that over a few years I upgraded through the full 30+ year progression from the original model G11s PUSH-TO #492 Digital Drive mount which I fully disassembled to rebuild and lube the internal bearings, then installing High Precision worms, aligning the gearbox output shaft so the Oldham coupler connection to the worm was as straight as possible, modifying the bearing blocks to encourage full worm bearing rotation and remove worm endplay using Belleville springs, adding a new modern era double clamp 8" Losmandy dual D/V saddle, experimentally making a one piece worm block with Belleville springs to use the bearings to preload the worms (this worked very well so I told Scott about it who then showed me what he was working on in secret which caused me to wait for over a year for the coming Losmandy spring loaded OPW) installing a Gemini 1 controller, building a regulated multi-voltage (13.5v & 17.5v) multi-bank power pack to support portable field use for visual and imaging work for 2 Losmandy Gemini mounts, installing a Gemini 2 system and then having Scott do the full update to the new OPWs, RA extension etc. then at a later date once finalized Scott added the spring loaded feature.? It has been a journey but what fun we had!? So was it worth it?? As I said for me it most certainly was.??
?
To answer the ASIAIR question it has been my experience that the ASIAIR is not quite as good at autoguiding as using a laptop and PHD2 on the same mount and imaging rig.? I say this because I relied on ASCOM and PHD2 and SGP for imaging and 5 years ago PHD2 produced excellent guiding on the same 20+ YO mount using the same guide scope and ASI120MM mini and ASI290MM mini.? The numbers are just not as good in absolute terms but what I have seen is that if you are guiding well under 0.5" total error and then the ASIAIR comes along and is guiding at 0.7" total error and I cannot see any advantage to putting up with all the extra trouble of using a laptop and a dozen cables to make it work I'm just not going to bother.? Give me the elegance of the ASIAIR solution anyday.
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Here is the small driveway imaging rig clamped to an old school Losmandy S-B-S dovetail on the even older G11G, LWT and Wheelie Bar.? The small imaging rig is an Askar FRA500 90mm f.5.6 Petzval working @ f/3.9, ASIAIR Plus 256GB v3, ASI2600MC-Pro main camera, EFW 2"x5, EFA w/temp probe, ASI678MM guide camera on Stellarvue 50mm f/4 guide scope, Deep Sky Dad Flat Panel and a Stellarvue 50mm visual finder.? Waiting for the CAA to show up, should be any day now LOL.? All of the components and most cables are on the scope and move with the scope except for 2 independent power cords and an Ethernet cord.? The ASIAIR Plus and Gemini 2 talk to each other through a high performance Slate AX1800 travel router via Ethernet and the tablet or phone use the Slate to connect over Wi-Fi.? ? ? ? ? ?
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric Forecast - South Pasadena, CA? ?
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Re: RA guiding awful after upgrade
On Thu, Jan 30, 2025 at 07:14 AM, Thomas Kallenbach wrote:
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No. You use PHD2 to autoguide but turn off corrections.? This will display the guide scope data used for correction which will show you the mount's basic mechanical tracking accuracy.??
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric Forecast - South Pasadena, CA? ?
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Re: RA guiding awful after upgrade
On Thu, Jan 30, 2025 at 12:36 AM, Thomas Kallenbach wrote:
Tom, just making sure: the mount had no such problems before you installed the RA Extension? Did you test it well prior to the installation? As others have said, the extension should have no effect on guiding, especially on one side of the mount. Something isn't properly engaging on the west side of your mount causing frequent jumps. I see some similar errors on the east side, although they are fewer and lower in magnitude. That's why I suggest collecting an unguided autoguider log on both sides. This will tell you how the mount behaves with simple tracking.
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Re: RA guiding awful after upgrade
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There are many potential issues with used mounts and even more with the now classic Losmandy straight line drivetrain with the 2-piece worm bearing blocks.? There are several places where issues can crop up.? Backlash, bearing blocks square and worm loaded axially no end play, bearings sticking, Oldham coupler set screws, gearbox fasteners, servomotor pinion mesh, servo motor fasteners etc. I'd also look in the drivetrain for something loose.??
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric Forecast - South Pasadena, CA? ?
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Re: RA guiding awful after upgrade
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It's a complex hobby.? Losmandy doesn't do nighttime testing so you are more likely to find the issue than they are and think of all the fun we'll be having! .??
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric Forecast - South Pasadena, CA? ?
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Re: Did my Gemeni 2 firmware become corrupt?
On Wed, Jan 29, 2025 at 04:07 PM, Paul Kanevsky wrote:
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Maybe do an HGM default reset then manually enter your settings.? If the memory has a bad couple of bits often the data corruption can walk through the memory making the problem worse until you notice something is weird.? Extreme cold and long hours of intermittent battery voltage may also have had something to do with it.? For that reason I would not trust any saved config files unless they are old enough to be well outside the possible data corruption time frame.??
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric Forecast - South Pasadena, CA? ?
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Re: RA guiding awful after upgrade
Hi Tom,
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I looked at your guide log with PEMPro Log Viewer and I see this log has multiple runs one after the other. So I am not sure which you consider having the problem and which are good. Attached is a screen shot of the very last one. Here we can see you have the typical 240s worm error which is not terrible (Y-axis in Arc-Sec). But you also have some 120s error, which is multiple of 240, and 32 secs which is the gear box. But all these values are changing from run to run suggesting you made mechanical changes between them. If you download this app from Ray Gralak's website, you can also open the log file and scroll through the runs. You may need to convert it to a Notepad text file first to open.?
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When we see these errors, we can sometimes correct them very well by creating a PEC curve using PEMPro (free for 60 days, not like the always free Log Viewer) and upload to the Gemini 2 unit. The upload curve should mostly correct for the common periodic errors and let your guide program correct for the seeing effects. In PHD2 we also use the PPEC corrective algorithm which can be used to correct for the largest magnitude error by setting the appropriate period in seconds. If you wish to proceed with PEMPro there is an instruction file on how to use with Losmandy mounts:
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I think these are the latest correct instructions. We still have no explanation why your mount changed from better to worse, so this may still involve some worm adjustments. There are a number of good videos on this subject on the Losmandy YouTube channel.
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John
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_____________________________________________________________________________________________________________________________________________________________________________ Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, NINA, Sequence Generator Pro and PixInsight user |
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Re: Did my Gemeni 2 firmware become corrupt?
On Wed, Jan 29, 2025 at 07:03 PM, Brian Maynard wrote:
I'd suggest that you just need to reset Gemini and set all the parameters from scratch. Possibly some setting got corrupted since your last session.
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Re: RA guiding awful after upgrade
On Wed, Jan 29, 2025 at 06:19 PM, Thomas Kallenbach wrote:
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I'd try to collect a few worm-cycles of autoguider data with actual corrections disabled -- just tracking on a star. Do this from both sides of the mount, and we can then see if the issue is mechanical or software/configuration related.
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It is also possible that, as was suggested previously, you wind up on different parts of the worm-gear when pointing from east or west sides, and if the gear is slightly eccentric, one side may cause a tighter worm mesh than the other. To check, move the scope 90 degrees in RA from CWD position (should be roughly at the meridian). Then, loosen the clutches and move the mount back to CWD manually, not using the motors. Turn off and cold start Gemini. This will shift the worm-gear by 90 degrees relative to where it was with your previous tries. Then, try guiding (or collecting unguided log data) from both sides, as before. See if things change because of the different position of the worm gear.
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Once you've done all of the things suggested already, the next step would be to see why or how the RA extension is causing this. You may need to loosen everything up, make sure nothing is askew, everything lines up properly. Reassemble carefully, don't overtighten. If that doesn't help, I would try to find out if the RAExt is actually what's causing it by removing it and testing again without.?
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Regards,
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? -Paul
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Re: RA guiding awful after upgrade
Thanks, Tom. You can use PHD log viewer to review the results of this log.?
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> ?Last night I adjusted the CW slightly so that it would be east-heavy.?
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When you say you adjusted it, what did you do? The weight needs to be re-adjusted after flipping to the other side of the mount to make sure the east side remains the heavier one. I'd just add a 2-3lb weight (a magnet?) to the CW on one side, and move it to the OTA side on the other.?
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It does appear that the error is significantly higher in RA on the west side of the mount, compared to the east. This is from the west side:
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And this is from the east. RA is better, although there are still occasional random spikes, though fewer and not as large:
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The large spike error doesn't repeat with the worm cycle, so is not caused by the worm (largest periodic error component seems to be at 2x worm cycle, magnitude of 1.4 arcsecs, so nothing major:
Regards,
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? -Paul
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On Wed, Jan 29, 2025 at 01:20 PM, Thomas Kallenbach wrote:
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Chip Louie
Paul Kanevsky
