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CGEM: What's the truth?

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#1 jrbarnett

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Posted 29 March 2010 - 09:46 AM

I find that folks having problems with gear are more likely to share their experiences on forums such as this than are folks who have a trouble-free experience with the same gear. This can create an imbalanced impression as to the reliability of certain products.

The CGEM seems (from the reports on this forum) to have its share of "teething" issues. My goal is to get a more balanced perspective as to whether the CGEM is a gremlin-ridden nightmare or basically a sound product with a few units missing the mark.

If you own or have owned a CGEM, please share your experiences both good and bad. If your use has been trouble free, please share as this is the kind of data that seems underrepresented.

Thanks,

Jim

#2 LLEEGE

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Posted 29 March 2010 - 10:08 AM

I never had any issues with mine.

#3 Corky

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Posted 29 March 2010 - 10:41 AM

Jim, are you already thinking you made the wrong decision getting a CPC, wishing you had opted for the equatorial mount instead? - Second-guessing your major pre-purchase evaluation?
In my opinion, you settled on the perfect design for visual; the fabulous Celestron alt-azimuth mount. All the noises it makes are totally normal and harmless. :)

#4 attckbvr

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Posted 29 March 2010 - 10:45 AM

I just bought a used CGEM from amart, It has preformed very well so far for me....no complaints

#5 SchrödingersCat

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Posted 29 March 2010 - 10:46 AM

My first unit had the dreaded "no reponse 16 (and 17)" issue. Sent it back and promptly received a replacement, which works fine with the exception that the number 3 hand pad light flickers.

#6 Fred1

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Posted 29 March 2010 - 11:36 AM

Near dead accurate gotos and excellent tracking when care is taken with a 2 star alignment with 4 star calibration and the polar alignment program. The stock knobs are an ergonomic nightmare, however, I bought the ADM upgrade kit along with the longer CW shaft which makes the mount much easier to set up and adjust.

It's heavy, so one must learn to lift it onto the tripod in one fluid motion without having to shift one's grip. Also, there is, at times, some very slight play in Dec, when the scope points in a certain direction, but it's only apparent when the scope or part of it is touched.

Even being aware of all of this, I'd still buy the mount again.

#7 joec33

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Posted 29 March 2010 - 11:39 AM

I love mine! No problems so far and is a pleasure to use every night out. The CGEM has also helped improve the overall quality of my CCD images too. My exposures are at least twice as long as they were with my ASGT. All around great mount for the money in my opinion.

#8 SanDiegoPaul

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Posted 29 March 2010 - 11:52 AM

I have had mine (new) for two months. It has travelled with me to the desert with the club twice, and been set up on the back patio on the weeks inbetween desert trips.

It is a very reliable performer.

Just this past weekend, I imaged with it again from my back porch - this time with NO polar alignment and stretching my image time from 10 minute subframes to 15 min subs. I imaged M108 under the 99 percent Moon for 75 minutes using those 15-min subframes. The only alignment done was the built-in All Star alignment procedure, using four calibration stars. Goto's are perfect when I use four calibration stars. the ST2000 camera does not have such a large chip in it.

But the GOTO's will always put the object very near center of my chip's FOV unless I'm swinging the mount all the way around, doing a polar flip.

This image was internally guided with the ST2000's built in guide chip, using 5 second pulses. The image shows good, round stars even though no drift or polar alignment was done. The only exception is the top left of the image, where my shots always show footballs because the camera doesn't sit in the SV90T APO squarely.

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#9 SanDiegoPaul

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Posted 29 March 2010 - 11:54 AM

I have had mine (new) for two months.

Here's a Leo Trio taken from this mount at ARizona Sky Village two weeks ago
.

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#10 Hank w

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Posted 29 March 2010 - 12:13 PM

I purchased one of the first CGEM's almost 1 year 3 months ago. I did have problems with the MC and HC control firm ware. When Celestron upgrade the firmware all was well. I have a fork mounted nexstar 9 1/4 which I am using less and less since I find the CGEM is much easier to setup and tote around. Once I got the setup and alignment routine down pat, I find it very easy, fast, and accurate to use. The CGEM is definitely louder than my fork mount at full speed, slower slews are much quieter, then again the top speed on the CGEM is a bit faster then the fork mount. I do have a P.E. bump the keeps showing up with every revolution which I have not tried to correct yet but will do so soon. I do like this mount and celestron's updating of firmware for discontinued products such as for my 91/4 GPS Fork mount.
Hank

#11 jrbarnett

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Posted 29 March 2010 - 12:20 PM

Not at all.

I'm actually considering upgrading my Atlas to a CGEM.

I have seven OTAs and three EQ mounts currently, in addition to the CPC.

Regards,

Jim

#12 waassaabee

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Posted 29 March 2010 - 01:09 PM

My CGEM operates flawlessly... now. I was having the No Response 16 & 17 errors and what finally appeared to be a dead hand control. When it returned from Celestron I looked at the worksheet and all they did was update the frimware (DOH!:foreheadslap:). But I think they did the mechanical adjustments as well, becase it moves like glass now. I think it's a fantastic and reliable mount.

#13 wsuriano

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Posted 29 March 2010 - 01:59 PM

I had a HC that died. Celestron sent me a new one. The mount works great. My experience is consistent with others - dead on gotos and a stable platform for imaging with the 2 star alignment, 4 calibration stars and All Star Polar Alignment. I'm usually up and running in 20-25 minutes from no set up at all to imaging.

Bill

#14 stevecoe

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Posted 29 March 2010 - 02:12 PM

That "thud" is me jumping on the bandwagon.

My CGEM does a great job, I have never had a problem. Visually, it is perfect. Once I got trained on using it, the object is in the central part of the field of view everytime. Until I let the battery get too low. Blame it on the human.

Photographically, I only do piggybacking. I have a 300mm lens and as long I keep the tracking accurately, it tracks smoothly and the images turn out great. For wide field stuff with my 35mm lens, I can go over the do some binocular observing while the CGEM tracks.

I also replaced the knobs, they were just too slippery. I bought from Scope Stuff.

Lots of fun;
Steve Coe

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#15 bob midiri

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Posted 29 March 2010 - 02:16 PM

Hi guys well I just bought one, it just arrived. Haven t even set it up yet. But have a few questions. What would you recommend for my situation. I own a Celestron 6" refractor and a Celestron SCT ULTIMA 9.25" which I now have both mounted on my ASGT mounts. I also only have these Vixen style dovetails on all my scopes. What do i need to do to get these mounted on the CGEM since this dovetail saddle is different. I have heard of ADM mentioned. Do they have a replacement saddle? TIA Bob Midiri

#16 bill kramm

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Posted 29 March 2010 - 02:32 PM

Bob, I got the AMD saddle for my CGEM. Worth every penny. Check out their web sie for other Cgen upgrades.

#17 bbbri

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Posted 29 March 2010 - 02:48 PM

CGEM is great. No problems so far, other than user created. It is my first GoTo mount. Now that I have learned the alignment routine, it points the C8 directly at the selected object. Milder weather has helped make alignment more fun. It takes about 15 minutes for 2 alignment + 4 calibration stars.

#18 attckbvr

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Posted 29 March 2010 - 02:48 PM

Bob buy all the upgrades from ADM if its in your budget, the dual saddle is great. The knob upgrades are wonderful as well. Just under $400.00 for everything. Scope stuff has the same upgrades for less money....BUT ADM's are bigger and look alot better. IMHO

#19 Jeff55

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Posted 29 March 2010 - 03:01 PM

Works extremely well...it was a long learning curve to get the goto right but this is my first EQ mount...I read the same articles and I unconsiously (on occassion) wait for something to go wrong (have got to stop reading those CGEM problem postings) BUT it is a great mount in every way and it just plain works.

#20 JadeSmith

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Posted 29 March 2010 - 03:51 PM

My first CGEM was louder than my CG5 and had a bad clicking noise. I promptly exchanged it (which was very difficult due to the vendor from whom I will never buy from again). The second unit has worked great for the last 9 months although it did act up once...a factory reset solved the "issue". Overall, I am pleased. (but you gotta buy a few ADM knobs to really enjoy it to the fullest IMO)

#21 jbattleson

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Posted 29 March 2010 - 07:19 PM

I bought a CGEM 1100 about 1 1/2 ago and have zero problems.
This is my 2nd scope. The first was an LX200 so have had a little problem getting use to GEM.
I am very happy with the CGEM. :jump:

#22 Fred1

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Posted 29 March 2010 - 08:49 PM

I forgot to mention in my earlier post that my CGEM typically carries about a 39lb payload. Yes, I'm visual only.

#23 Locoweed

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Posted 29 March 2010 - 09:04 PM

Lets ignore the fact that mine is in the shop right now & talk about some niggling details that irritate me. You have probably read about the short cord on the HC, it's also very stiff in cold weather. I also do not like having the cord come out the back instead of the bottom. Having the connection for the computer routed through the HC means you have 2 cords to deal with when using it.

The instruction manual is something I would expect from a really cheap setup from Wally World.

The adjustment for Dec sux big time if your down around 30 degrees like I am.

On the other side, it has some neat features & if they can get my problem (Gear mesh I think)fixed I will be satisfied with it.

I guess what bugs me the most is that I would have been happy to spend a couple of hundred more on the mount if they would have fixed these & some other minor issues that would not have cost them much to have done right the first time.

#24 ScoJo

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Posted 30 March 2010 - 01:28 AM

I loved my CGEM for the two months it worked properly. It's at Celstron for repair now.

#25 mak7

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Posted 30 March 2010 - 01:41 AM

I have had mine for 6 days. When I set it up inside to just check function ( without an OTA ) I did a false alignment and got one 16 error and one 17 error. I repeatedly hit undo and luckily was able to continue. I have had the mount out twice loaded with an OTA and observed for many hours without a problem. Maybe the weight was needed for the encoders ? I pre spread the center contact in the power connector before it came out of the shipping foam. I read the threads !!! Thus far, the weak link appears to me to be the tripod, not very robust at all for the size of the GEM head. More time will tell.
Brad






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