CGX - READ CAREFULLY

I got this mount used a month ago but I'm failing to dial it in.

When I received the mount I heard low-frequency RA motor sound when lifting counterweights up and "stalling" DEC motor sound when slewing, so I opened the motor housing and found that both axis were locked down tight. Then I spent countless hours setting the mesh and spring tension. I eliminiated the spurious motor sounds on both axis and saw mininal if any movement when I wiggled the dovetail or counterweight bar. The motor sounds were pleasant after that

However, when I run GA in PHD2 I also identified a +/- 10" PE which had a period of ~30min. I was suspecting that was the PE from something other than the worm, as CGX worm only has a period of 478 sec. I don't have the time or effort to investigate further.

I also replaced the DEC timing belt with another belt with the same specification from ebay as the previous one showed some cracks due to reasons unknown. I have another spare rubber belt that I could throw in as replacement parts. I've measured DEC backlash to be 30 arc-seconds, give or take, through PHD2's Guiding Assistant. Celestron personnel said that a typical CGX /CGX-L has 60-150 arc sec of backlash, so this value is definitely better than what you'll get from an average CGX.

Basically, if you can figure out why there is a problem for RA you're basically stealing the mount from me.

Typical guiding error was ~0.8"-0.9" for RA and <0.6" for DEC(have proof) and is not going to support my image scale of 0.77". I can see trailing caused by the RA axis for exposures more than 4min guided.

Mount sold as-is with the above condition and with no returns.

I’m willing to ship CONUS if you pay full shipping, which is expected to be $150-200. Decided to get rid of this mount as soon as possible, so if you're interested, we could easily start a discussion.


You will get everything that comes with the mount, and that includes the mount head, the tripod, two 11lb counterweights with counterweight shaft, hand controller, tripod spreader, and the carry handle.