Jump to content


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


CGEM problems fixed?

  • Please log in to reply
10 replies to this topic

#1 docchilie


    Lift Off

  • -----
  • topic starter
  • Posts: 12
  • Joined: 17 Jul 2012
  • Loc: Parnell, Iowa

Posted 30 October 2012 - 01:54 PM

A new mount is in my near future and I've been researching this quite a bit, but I can't find any definitive information in my Google searches.

I've read many old threads highlighting the issues CGEM had, but many of them are a year or more old. I've seen recent posts in mount threads where people reference that the CGEM problems are resolved, but nowhere can I find exactly what was resolved.

One of my main concerns was the reliability and the ability to operate in cold. Someone said that the lubricant used would be too viscous at what I thought were average cold temperatures here in Iowa.

If I'm buying new, I've narrowed down to CGEM, Atlas or IEQ45. The IEQ45 freaks me out because it is so new. The CGEMs reputation is freaking me out, so I'm down to the Atlas, but some of the CGEMs features I find interesting.

Thanks for the help.

#2 Baxstar



  • -----
  • Posts: 48
  • Joined: 15 Sep 2012
  • Loc: The Netherland

Posted 30 October 2012 - 01:58 PM

I have my CGEM almost a year and have no problems with it! Really like it!


#3 bbbri


    Vostok 1

  • -----
  • Posts: 141
  • Joined: 05 Nov 2009
  • Loc: SW Ohio, United States

Posted 30 October 2012 - 02:15 PM

Haven't been hearing about as many issues with the CGEM lately but it's hard to tell. I had to return mine to Celestron for repair 2 years ago but it's been working since then.

#4 Starhawk


    Space Ranger

  • *****
  • Posts: 6189
  • Joined: 16 Sep 2008
  • Loc: Tucson, Arizona

Posted 30 October 2012 - 02:26 PM

I've been using two of them without trouble.


#5 Lane



  • -----
  • Posts: 3599
  • Joined: 19 Nov 2007
  • Loc: Frisco, Texas

Posted 30 October 2012 - 03:50 PM

Never had trouble with mine but I have never used it below 20 degrees so can't comment on how it would do in extreme cold. It was bought within 6 months of the initial release. I don't treat it very well either, it gets used a lot in heavy dew and I keep the mount in the trunk of the car most of the time where it gets bounced around, so it seems to be very well built to handle all that and still work so well.

It is noisy IMO, maybe not as bad as an LX200 but enough that I don't use it in the backyard where it would bother the neighbors. If that is an issue for you then consider the Atlas instead, it is fairly quiet and is basically the same mount. If I was going to choose between them today I would probably go with the Atlas just because of the noise issue.

#6 mich_al



  • *****
  • Posts: 3006
  • Joined: 10 May 2009
  • Loc: Rural central lower Michigan Yellow Skies

Posted 30 October 2012 - 10:55 PM

I used my CGEM thru a Michigan year before I had it supertuned and never had any issues with its grease.
I think the biggest issues the CGEM had where QC at the end of the production line, resulting in many problems that should never have happened, and customer service when the mounts failed. Mine was back to Torrance for repairs twice in the first 18 months, I'm over 3.5 years now. Replacemnt parts are nearly non-existant and replacement motors are WAY overpriced. Other than that it's a pretty good mount for its price & weight class. I thinks it's hand controller software is as good as anything out there though there still seem to be a bug or two and a deficientcy here or there. I'm 100% visual, pier mounted and have mine loaded to nearly max.


#7 docchilie


    Lift Off

  • -----
  • topic starter
  • Posts: 12
  • Joined: 17 Jul 2012
  • Loc: Parnell, Iowa

Posted 31 October 2012 - 10:32 AM

Thanks, everyone. Neighbors aren't a problem out here. It could be powered by an un-muffled V8 and no one would care.

#8 Raginar



  • *****
  • Posts: 8078
  • Joined: 19 Oct 2010
  • Loc: Rapid CIty, SD

Posted 31 October 2012 - 05:47 PM

Mine worked fine outside in SD during the winter; most of my issues were user-generated.

It worked alot better after it was hypertuned. Better being defined as it produced a smooth(er) PHD graph and was easier to balance. GOTO was much improved as well.

#9 YetAnotherHobby


    Mariner 2

  • *****
  • Posts: 286
  • Joined: 02 Sep 2009
  • Loc: Central CT

Posted 01 November 2012 - 07:22 PM

I bought my CGEM DX this past March. I had some initial problems with alignment, but after updating the firmware (10 minute operation, free downloads) I have had zero issues. The goto accuracy is a huge improvement over my Nexstar 8i, and precise goto just knocks my socks off. I was looking for a fairly faint galaxy visually with no luck. I swapped in the Stellacam, used precise goto, and on the first integration, there she was, dead center. I love this mount!
There is a Yahoo group and those guys know this mount intimately. Their advice helped me resolve the alignment issue. I have noticed a steep falloff in traffic on that group - maybe the bugs have all been worked out?

#10 Stew57



  • *****
  • Posts: 2731
  • Joined: 03 May 2009
  • Loc: Silsbee Texas

Posted 01 November 2012 - 09:31 PM

The vast majority have good pointing accuracy. Those that don't point well are defective (disregarding operator error induced problems) They all will keep an object in a high power eyepiece all night. Now tracking for ap work is a totally different mnner.

The cogging effect is still present on many mount (mine does not have it) but a firmware fix is being worked on for that and the effect does have some work arounds.

PE is quite variable. i have had 3 cgems and they ran from 16 (+-8) arc seconds to 180 (+-90) arc seconds. The 180 arc second mount was returned and replaced under warranty. As long as the PE is smooth it can be guided out anyway.

There is a non integer PE component. It Runs at 8/3 worm revolution. For some mounts it is actually higher than the worm PE. Mine runs 75% of the 1st integer and does not guide well. It also makes PEC rather useless in my case. Not all cgems suffer from this os as bad.

My take on the cgem is it is a good value. I would look at it or the Atlas. For longer FL AP this mount is not it.

#11 EFT


    Vendor - Deep Space Products

  • *****
  • Vendors
  • Posts: 3826
  • Joined: 07 May 2007
  • Loc: Phoenix, AZ

Posted 02 November 2012 - 10:15 AM

Interestingly, the CGEM DX Yahoo group tends to have very little traffic and, as far as I can tell, an indication of relatively few problems which I attribute to its different motor board.

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics