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RA sags on CGEM-DX

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#1 MRNUTTY

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Posted 17 June 2013 - 05:35 AM

6 months (and only 5-6 uses) after I bought my CGEM-DX it developed a severe problem; when moving to a position between 0-45 degrees above the horizon the mount will track to the correct position then sag down, away from the correct position by 10-20 degrees along the RA axis. These early uses were with the heavy AT12IN.

At the time I had purchased the iEQ45, and a few lighter alternative scopes, so I shelved the problem. My observatory is ready to accept a mount; so I provisioned the ability to accept both iEQ45 and CGEM mounts on the primary Pier. The CGEM is intended for AP, so I'm sending the mount out for Hypertune at DeepSpaceProducts for the tune, and I seem to remember they can also repair faulty issues with the product as well.

Is my recollection sound?

thx!
john

#2 rmollise

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Posted 17 June 2013 - 08:30 AM

What does "sagging" mean? That the go-to is off? The tracking is off?

#3 MRNUTTY

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Posted 17 June 2013 - 09:21 AM

The Goto is right on I think, not much time to tell. However, it will then immediately sag, move down, drop, lax, reduced vitality, nothing to keep it up; so it drops about 10-20 degrees dependiing on where the Goto stopped at. It seems to track from this position, but it's still off by however many degrees it sagged by. The Dec positioning is fine, it's just the RA positioning.

Description make sense now Rod?

#4 rmollise

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Posted 17 June 2013 - 09:54 AM

Not really...sorry. Does the scope move, do the motors engage...or does it not seem to be tracking in RA...or is there mechanical slack somewhere?

Make sure clutches are secure and that the head is firmly attached to the tripod and that the alt bolts are tightened down. Other than that? Sounds like time for Mr. Ed, who will likely be along soon... ;)

#5 MRNUTTY

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Posted 17 June 2013 - 11:08 AM

In fact, Ed found my post here :-) we're working it out in addition to getting it hypertuned.

Thanks Uncle Rod!

#6 RTLR 12

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Posted 17 June 2013 - 12:05 PM

One of the hardest parts of my business was getting people to explain their mechanical problems. I had one lady that could only explain to me that her key didn't work. Not until after a very long and painful inquisition did I surmised that what she meant by her key not working was that when she put the key in the ignition and turned it, the key did not work...She had a dead battery!

Stan

#7 cn register 5

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Posted 17 June 2013 - 04:15 PM

It's difficult to come up with any suggestions other than balance and tightening the clutches.

Chris

#8 MRNUTTY

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Posted 17 June 2013 - 06:58 PM

Chris, yeah, those occurred to me. Luckily, my next step is DeepSpaceProducts.com where Ed will repair it along with a Hypertuning then back to the observatory!






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