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CGEM DX Tracking Stops

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#1 DwainM

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Posted 07 June 2013 - 09:56 PM

Hi Y’All,
I need some help on my CGEM DX please.

I'll be enjoying Saturn or some star cluster and suddenly it will just start to slide right out of the field of view. My batteries are charged up, I’ve balanced the OTA on the mount with all accessories attached, I’ve done a good alignment, the scope responds to commands from the hand controller… I don’t get it. :confused:

Here’s the strange thing:
When this happens, if I grab the scope and move it wiggle it by hand the mount will suddenly spring to life and seem to catch up with the object I was viewing.

As I’m writing this it makes me think that something is sticking or stopping the movement until I make it move. I have a Deep Space Products DIY Hypertune Kit for it but before I take the thing apart I thought I’d mention it here in case there is some sort of know issue with this mount that requires returning it to the factory.

Thanks! :bow:
Dwain

#2 cn register 5

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Posted 08 June 2013 - 04:05 AM

You have hit the tracking limit, about 20 deg past the meridian.

Do a slew to Saturn and the mount will do a pier flip and will continue to track Saturn.

Chris

#3 cclark

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Posted 08 June 2013 - 10:38 AM

I had the same issue on my DX. It was not near the limit stops and was very unpredictable. It would seem to hang up or stop tracking but a light touch (or wiggle) would cause it to spring back to life and begin tracking again. This was really starting to worry me as it was happening pretty frequently, but seemingly randomly.

I did the DIY hypertune with the kit and it has not happened since. It has been almost a year since doing the tune up. I think it may have been a paint fleck in the gears. During the hypertune, I found several paint chips and metal shavings inside that may have contributed to the binding.

Also, check that you are running latest firmware. I would suggest joining the Team Celestron beta test group (teamcelestron.com) and trying the latest beta release of the motor firmware. It has really done wonders for the dec cogging issue when guiding. Between the hypertune and the latest firmware, my DX is performing very well.

I hope this helps.

Chris

#4 EFT

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Posted 08 June 2013 - 11:49 AM

If you are not hitting the slewing limits, then what is likely happening is that the gears are binding due to either incorrect worm spacing, too far off balance or both. When the gears in a servo system bind slightly but not completely, when they break free the motor will momentarily rush forward as a result of the increased power being supplied to them as a result of trying to overcome the binding. You definitely want to get this problem solved because eventually it could do damage to the motor by stripping off or bending the teeth on the nylon gear in the motor gearbox. As the previous poster suggested, the problem is likely to go away once the mount it tuned up so that it is more easily balanced and has proper worm centering and spacing.

#5 DwainM

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Posted 08 June 2013 - 10:19 PM

You have hit the tracking limit, about 20 deg past the meridian.

Do a slew to Saturn and the mount will do a pier flip and will continue to track Saturn.

Chris


Thanks Chris,
I'll watch for it again when I'm near the Meridian. I do believe I've seen it in other areas of the sky as well though.
BR
Dwain

#6 DwainM

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Posted 08 June 2013 - 10:25 PM

thanks Chris,
I signed up. Let's see where that gets me. I think tuning the mount is the way to go but it'll have to wait a few weeks. I have some travel to do for work.
The problem must be related to the must sticking mechanically.
I'll report back when I'm done.

Dwain

#7 DwainM

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Posted 08 June 2013 - 10:31 PM

Hi Ed! Thanks for the info.
I like to think that I can balance the setup fairly well but I did notice some tighting of the movement when I'm swinging the scope during balancing.
I'm sure tuning it up will help.
I have the Hypertune kit ready to go, I just need the time to do it.
BR
Dwain

#8 DwainM

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Posted 03 July 2013 - 05:15 PM

You have hit the tracking limit, about 20 deg past the meridian.


You got it right Chris. Once I paid more attention to what part of the sky I was looking at it was obvious.
I haven't had this problem since then but I'm glad I got my DIY Hypertune kit. I tackle that this weekend.

Dwain






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