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CGEM motor cogging

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#26 Mike X.

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Posted 22 March 2013 - 05:17 PM

Very true Rod ;)

Geo..true..steppers have their cons too but so far the SW seems to have a better record.
I am a celestron fan personally... But if the steppers provide me the same tracking resolution with they servo counterparts that's what made me think I favor of them,


#27 tboconnor

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Posted 23 March 2013 - 01:11 AM

I just checked mine - when I set the rate to 2, and look at the RA and DEC numbers, I dont see any pauses or movement back when moving the mount.

Does this mean I dont have a cogging issue?

#28 Raginar

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Posted 23 March 2013 - 08:46 AM

tboconnor,

You won't see it until you're guiding. Your PHD graph will have a 'sawtooth' pattern in declination.

Very frustrating, and the reason most of us get rid of our CGEMs. Mine was 'fixed' via hypertuning (thanks Ed!) but only at lower weights than I wanted (<20# was the sweet spot for my particular mount).

I was up front when I sold it.

Chris

#29 svtdoug

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Posted 23 March 2013 - 10:37 PM

I just checked mine - when I set the rate to 2, and look at the RA and DEC numbers, I dont see any pauses or movement back when moving the mount.

Does this mean I dont have a cogging issue?


With the mount balanced in Dec, if you are pressing short (about half a second) blips with the hand control in dec, and the dec numbers continue to go up or down, without any hangups, or rollback, then you likely do not have the issue. Do check both directions though. Check going one way for a minute of short bursts, then reverse and check the other direction for a minute or so. But as Chris suggested, check your PHD guiding graph for any sawtooth pattern in dec to make sure. If you want more information on this check - I posted a video further up this thread.

Cheers,
Doug

#30 svtdoug

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Posted 09 April 2013 - 01:44 AM

Just a quick update on the cogging issue. We received a new beta motor control firmware version from Celestron about a week ago for testing. The early test result are encouraging. The dec cogging seems to be cured, no sign of it from any testers. There are several intermittent issues that we and Celestron are dealing with, but those might be due to other things than the firmware, a sick RA motor in my case. I have done a lot of testing, but all indoors, as we have had non-stop cloud cover since the beta release. Other tester have been able to guide and the results are good, so far.

The bottom line is that Celestron heard from the user community and put the resources where they need to be to get this problem solved. Hopefully there will be a stable version soon for public release.

Thanks for all who commented about this issue.

Doug

#31 jonbosley

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Posted 09 April 2013 - 10:21 AM

That is very good news Doug I am glad Celestron are finally addressing the issue, it has most likely hit sales as they have know about this issue for a long time.

#32 Raginar

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Posted 09 April 2013 - 12:13 PM

That was always the problem in the past. They had some software ideas to get rid of the cogging, but it always hard broke some other routines.

Hopefully they can figure it out. I really liked my CGEM.

#33 Mike X.

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Posted 09 April 2013 - 01:07 PM

I'm really glad they come out with a fix!!! Thats great news!! (even if i just bought an azeq6gt 2 weeks ago...Couldn't wait anymore )

#34 dickbill

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Posted 09 April 2013 - 03:01 PM

That's great news. Assuming that happens and we can download the upgrade from C, does it require a special cable ? i never did that.

#35 Raginar

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Posted 09 April 2013 - 03:15 PM

Dickbill, you'll need a cable like you use to do computer control.

Also, they thought they had this fixed last year too. Don't hold your breath. The guy who does it ends up getting pulled to work other projects; they already have your money :D

#36 svtdoug

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Posted 21 April 2013 - 05:48 PM

I'm pleased to report that beta testing is going well for the CGEM motor control firmware update that addresses the Dec cogging issue. We are testing the second version this month and results are very good - no dec cogging, and dec RMS values of 0.25 pixels during guiding has been achieved.

But, we need more testers. If you have a CGEM, and are somewhat familiar with updating the firmware via MCUpdate, and can do somewhat controlled tests and write concise reports of the results, and would like to participate - here is how:

1. Go to Teamcelestron.com and register as a member.

2. If you don't already have MCUpdate and HCUpdate installed on your computer, go to the Celestron website, download and installed these two programs. These are the required programs to update your mount's firmware.

3. Go back to the TeamCelestron website, click on the Firmware link, then the Motor Controller section, then the Version 31.07 section. Read through this section to get an idea of what is going on. It also would not hurt to read through the previous version 30.91 thread to see what issues have come up and have been resolved.

4. Download the 31.07.cel file. Its in the first post by Derik in the 31.07 section and install it in your Motorcontroller folder (which will be created on your computer when you install MCUpdate.exe).

5. Run MCUpdate.exe. The beta version 31.07 will now be in the list of available firmware updates. Select it and load it into your mount for both axis - Azmith and Alt.

6. Read all the disclaimers about testing beta firmware, understand the risk, and please test every function that you have ever used with your mount. All the utilities and Setup functions. You can do a lot of testing indoors if you have cloudy conditions. Of course, setup, aligning, ASPA, and guiding under the stars is the best test.

The more testing we can accomplish, the quicker this version will be released to the public.

If you have any questions, please ask!

Thanks!

Doug

#37 gmartin02

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Posted 21 April 2013 - 07:18 PM

That was always the problem in the past. They had some software ideas to get rid of the cogging, but it always hard broke some other routines.

Hopefully they can figure it out. I really liked my CGEM.

This is incorrect. The other big introduced problem (that was so hard to track down) in the firmware that addressed the Dec cogging issue was unrelated to the Dec cogging fix. It's a long story, but available by reading the TeamCelestron motor control forum posts.

#38 amdizack

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Posted 21 April 2013 - 07:41 PM

I have had my CGEM for 6 months, and just noticed this issue last night. I ONLY had the issue when I was imaging East of the Meridian. Anything I started tracking in the West came out just fine.

Does this fit into the category of this CGEM issue? Or would I see it East AND West of the meridian?

#39 gmartin02

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Posted 21 April 2013 - 07:41 PM

Dickbill, you'll need a cable like you use to do computer control.

Also, they thought they had this fixed last year too. Don't hold your breath. The guy who does it ends up getting pulled to work other projects; they already have your money :D

If you were holding your breath, it might be almost time to exhale.

As Doug said above, we have gotten 2 new beta versions in the last 3 weeks, and the latest version is guiding really well in Dec (for me now better than guiding in RA). We could use some more beta testers.

Note: The new motor control firmware is based on "beta" code (not just a tweak to the existing release code, but a re-write from scratch), and has not been thoroughly "fine tuned" yet for public release. That being said, I am now able to use the current beta MC release for multi hour unattended guided imaging without issues.

"The guy who does it..." actually has a name, which is Derik.

Derik, you rock!

Greg

#40 gmartin02

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Posted 21 April 2013 - 08:56 PM

I have had my CGEM for 6 months, and just noticed this issue last night. I ONLY had the issue when I was imaging East of the Meridian. Anything I started tracking in the West came out just fine.

Does this fit into the category of this CGEM issue? Or would I see it East AND West of the meridian?


My CGEM initially had more problems Dec guiding close to the pole. With more use, as the mount continued to break in, the Dec cogging issue appeared to become worse across all latitudes, regardless of which side of the meridian I was guiding on. I wonder if the object(s) you were guiding on East of the meridian was higher in celestial latitude than the object(s) West of the meridian?

#41 tboconnor

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Posted 22 April 2013 - 10:35 PM

This is really great news - I have one of the older hand controllers - will I be able to update it with this firmware?

#42 wolfman_4_ever

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Posted 22 April 2013 - 11:14 PM

looks like Derik just released 31.11 beta and it for the cgem's and cge-pro's..

Go join the beta team!

#43 gmartin02

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Posted 23 April 2013 - 02:11 PM

This is really great news - I have one of the older hand controllers - will I be able to update it with this firmware?

I am pretty sure the answer is "Yes". I think any of the CGEM supplied HCs can be used to upgrade the newest HC or MC firmware. It's best to upgrade to the most recent "official release" HC (4.21) & MC (6.17) versions and make sure those work on your mount before trying a beta MC version.

You can check your firmware versions by using the Version option on the Utility menu in the HC.

#44 svtdoug

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Posted 30 April 2013 - 02:37 PM

Beta testing going well, now have third version this month. Only remaining small bug is we are getting some bumps in dec guiding when using anti-backlash settings, if the dec changes directions. No reports of any dec cogging from about a dozen testers.

Jointly, Derik from Celestron is testing the same firmware version for CGE Pro mount. If you have a CGE Pro mount, Derik needs beta testers badly. If you can test - please go to TeamCelestron.com, register and follow the thread on Firmware/MotorControl/Version 31.15.

Thanks,
Doug

#45 WesC

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Posted 30 April 2013 - 04:23 PM

Cool, thanks for the update. I haven't started AP with my CGEM, but I have a feeling this will be a must have when I do.

#46 TimP

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Posted 30 April 2013 - 04:57 PM

This is great news. Thanks for updating the post.

Tim

#47 tboconnor

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Posted 30 April 2013 - 05:39 PM

I've been using the beta for a few days. I haven't really

Y been able to properly test it for AP, but I like the way the. Motors behave when slewing. Seems a lot more precise for some reason.

#48 svtdoug

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Posted 23 May 2013 - 08:39 PM

We thought the new motor control firmware would be released by now, but there have been several users with strange results, and Derik is exploring whether they are due to hardware issues or the firmware.

But here is proof that the new firmware solves the dec cogging issue. This image is my first with my C8 at the full 2000mm fl. I never was able to guide well enough to attempt before.

This image consists of 23, 5min frames, with no throw-outs. It was shot 3 days before a full moon, on 4/22/13, so it did have some gradient issues, but I was pretty pleased with the guiding.

M-51
CGEM with 31.17 beta MC firmware
C8 OTA
ST80 and SSAG for guiding
Modified Canon XSi
Captured with Backyard EOS, stacked with DSS, processed with PS-3.

Doug

Attached Files



#49 Raginar

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Posted 24 May 2013 - 02:36 AM

Wow Doug, gorgeous :)

#50 Stew57

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Posted 24 May 2013 - 08:36 AM

I wish they would have just fitted the VX motors into the CGEM/DX. Would solve the 8/3 error and the cogging. Seems a waste to spend all this time developing firmware that will have to be replaced if motors and control board are changed. I hope they are still going to do the change. I do hope they have not changed their mind.






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