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Equipment Discussions >> Mounts

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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
CGEM: What's the truth?
      #3712248 - 03/29/10 10:46 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


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LLEEGE
True Blue
*****

Reged: 03/03/05

Loc: Cloud-chester,NY
Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3712288 - 03/29/10 11:08 AM

I never had any issues with mine.

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Corky
scholastic sledgehammer
*****

Reged: 04/22/08

Loc: Ohio, USA
Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3712366 - 03/29/10 11:41 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.


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attckbvr
Carpal Tunnel


Reged: 11/11/08

Loc: British Columbia, Canada
Re: CGEM: What's the truth? new [Re: Corky]
      #3712375 - 03/29/10 11:45 AM

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

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SchrödingersCat
sage
*****

Reged: 11/02/08

Re: CGEM: What's the truth? new [Re: LLEEGE]
      #3712377 - 03/29/10 11:46 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.

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Fred1
Carpal Tunnel
*****

Reged: 09/19/07

Loc: Somewhere in the Orion Spur
Re: CGEM: What's the truth? new [Re: SchrödingersCat]
      #3712468 - 03/29/10 12:36 PM

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.


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joec33
sage
*****

Reged: 06/13/09

Loc: Orange County, NY
Re: CGEM: What's the truth? new [Re: SchrödingersCat]
      #3712473 - 03/29/10 12:39 PM

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.

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SanDiegoPaul
Carpal Tunnel
*****

Reged: 07/22/05

Loc: San Diego
Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3712502 - 03/29/10 12:52 PM Attachment (133 downloads)

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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SanDiegoPaul
Carpal Tunnel
*****

Reged: 07/22/05

Loc: San Diego
Re: CGEM: What's the truth? new [Re: SanDiegoPaul]
      #3712508 - 03/29/10 12:54 PM Attachment (119 downloads)

Quote:

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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Hank w
member


Reged: 09/10/08

Loc: Loveland, Colorado
Re: CGEM: What's the truth? new [Re: joec33]
      #3712545 - 03/29/10 01:13 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


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: CGEM: What's the truth? new [Re: Corky]
      #3712561 - 03/29/10 01:20 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


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waassaabee
Postmaster
*****

Reged: 11/26/07

Loc: Central California Coast
Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3712659 - 03/29/10 02:09 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!). 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.

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wsuriano
super member


Reged: 11/13/07

Re: CGEM: What's the truth? new [Re: waassaabee]
      #3712747 - 03/29/10 02:59 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


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stevecoe
"Astronomical Tourist"
*****

Reged: 04/24/04

Loc: Arizona, USA
Re: CGEM: What's the truth? new [Re: wsuriano]
      #3712774 - 03/29/10 03:12 PM Attachment (93 downloads)

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

Edited by stevecoe (03/29/10 03:13 PM)


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bob midiri
Carpal Tunnel
*****

Reged: 06/17/04

Loc: pa 19320
Re: CGEM: What's the truth? new [Re: Fred1]
      #3712787 - 03/29/10 03:16 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

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bill kramm
member
*****

Reged: 04/20/09

Re: CGEM: What's the truth? new [Re: bob midiri]
      #3712820 - 03/29/10 03:32 PM

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

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bbbri
super member


Reged: 11/05/09

Loc: SW Ohio, United States
Re: CGEM: What's the truth? new [Re: bill kramm]
      #3712850 - 03/29/10 03:48 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.

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attckbvr
Carpal Tunnel


Reged: 11/11/08

Loc: British Columbia, Canada
Re: CGEM: What's the truth? new [Re: bill kramm]
      #3712851 - 03/29/10 03:48 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

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Jeff55
professor emeritus


Reged: 04/14/05

Loc: Boston MA
Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3712870 - 03/29/10 04:01 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.

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JadeSmith
scholastic sledgehammer
*****

Reged: 07/15/08

Loc: SE Michigan
Re: CGEM: What's the truth? new [Re: Jeff55]
      #3712978 - 03/29/10 04:51 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)

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jbattleson
Happily Retired
*****

Reged: 03/02/09

Loc: Nebraska
Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3713414 - 03/29/10 08:19 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.


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Fred1
Carpal Tunnel
*****

Reged: 09/19/07

Loc: Somewhere in the Orion Spur
Re: CGEM: What's the truth? new [Re: jbattleson]
      #3713615 - 03/29/10 09:49 PM

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

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Locoweed
sage


Reged: 06/27/07

Loc: Texas
Re: CGEM: What's the truth? new [Re: jbattleson]
      #3713640 - 03/29/10 10:04 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.


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ScoJo
member


Reged: 11/17/09

Loc: Birmingham, Alabama
Re: CGEM: What's the truth? new [Re: Locoweed]
      #3714026 - 03/30/10 02:28 AM

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

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mak7
sage
*****

Reged: 09/29/07

Loc: light polluted Phoenix AZ
Re: CGEM: What's the truth? new [Re: ScoJo]
      #3714042 - 03/30/10 02:41 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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BlueGrass
Carpal Tunnel
*****

Reged: 07/25/09

Loc: Wasatch Front, UT
Re: CGEM: What's the truth? new [Re: ScoJo]
      #3714051 - 03/30/10 02:56 AM

I've had my CGEM for 6 months and it is a very stable, accurate mount. I still use my CG5 for visual but when I want to do imaging, I use the CGEM. It IS a heavy mount and requires some strength to lift the head onto a fully extended tripod. You won't be carrying the tripod and head assembled very far. I've found once you do the 2+4 alignment and PA routine, my CGEM repeatedly puts the DSO targets on the CCD with only a minor adjustment necessary for centering. Once aligned, I use my laptop to control the mount with Cartes. I've only had one problem with my mount this past winter due to cold temps. I got the 17 error code twice but that was fixed by reseating the internal motor connectors attached to the control panel. I made my own HC extension (a must upgrade) and replaced the stock saddle with the ADM dual saddle. IMHO, the dual saddle is also a must upgrade. It's well crafted with typical ADM quality. Overall, I have to say with the HC firmware and the tracking performance, the CGEM is an excellent mount. I thought seriously about the Atlas before purchasing the CGEM, but the HC firmware made the decision for me.

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AntarcticDave
sage


Reged: 02/03/09

Loc: Denver, CO
Re: CGEM: What's the truth? new [Re: BlueGrass]
      #3714454 - 03/30/10 10:56 AM

I bought mine about 14 months ago, and it has perfomed very well. I have been impressed with the pointing accuracy and love the All Star polar alignment routine. Once they became available I added an extra 11 lb CGEM weight, as I have about 32 lbs on mine (before that I used an extra weight I had around from my old CG3).

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Stew57
Carpal Tunnel
*****

Reged: 05/03/09

Loc: Silsbee Texas
Re: CGEM: What's the truth? new [Re: AntarcticDave]
      #3715359 - 03/30/10 06:44 PM

I have had mine for 6 months or so. The hand controller died after 3 days. The new had to be updated but worked fine. The controller had to be reset to factory settinge when the mount started thinking down was up. it gave a error 16 once but a power down and back up seems to have solved the problem. I agree that a few hundred more for a few small fixes would have been nice.

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R Nitzel
member


Reged: 01/14/09

Loc: Owasso, OK
Re: CGEM: What's the truth? new [Re: Stew57]
      #3715554 - 03/30/10 08:16 PM

I received mine back from the shop on Friday. Last night, it, after 1 1/2 nights of imaging, it quit AGAIN. Talking to Celestron tech support manager, so we'll see what they offer up this time. Even though it has spent 4 of the last 12 months (approximately) in the shop, over 4 trips, I really can't find a mount I like better without having to take out a small loan. When it works, it works really well, and when it quits, it quits all the way. I'm looking around for something different, but I really like the polar-alignment routine, the easy setup, and the solid feel. The tracking is pretty smooth. I keep hoping/thinking that if I hang onto it long enough, eventually all the parts will get replaced by warranty.

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tedbnh
scholastic sledgehammer


Reged: 11/14/07

Loc: New Hampshire
Re: CGEM: What's the truth? new [Re: Stew57]
      #3715555 - 03/30/10 08:18 PM

I bought mine used and had it out twice, once for myself and once at a star party. It worked fine both times, even without using the all star polar alignment process. But I found myself unhappy with the slop in the gears, which made for too much vibration when I focused. Called Celestron - tough luck, warranty applies only to original purchaser. They would let me ship it back to them pre-paid both ways and then once they got it they'd tell me if they could tighten it up and quote me a price. Well, I figured if anybody is going on vacation to California it's going to be me, not my mount!

So, I shipped it off to Tom Hadoulias at Astro Motion Technologies for his tighten-up tune-up. When I add his price to the price of the used mount, I will have paid just factory price but will have a zero-backlash mount with all new lube. Should be back next week. (ADM knobs on order too, hope they get here before the mount).


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: CGEM: What's the truth? new [Re: tedbnh]
      #3716810 - 03/31/10 01:35 PM

Interesting posts folks. It seems like there are still some teething pains with the mount. Issues with Celestron hand controllers aren't unique to the CGEM; the same issues have plagued recent CPC scopes too using the same controller. Those issues should be easy to sort out (by getting the supplier of the faulty HC parts to replace them). The other issues, however, are a little more disconcerting. Hopefully in another 6 months Celestron will have the kinks straightened out.

Regards,

Jim


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glennstevens
member


Reged: 05/08/09

Re: CGEM: What's the truth? new [Re: tedbnh]
      #3716836 - 03/31/10 01:44 PM

I owned my CGEM 9 months. It has been set up at least 50 times. No problems. I'm using it with a C8 and I find the set up real stable. I was thinking of going to a C11. I have heard the mount isn't stable enough for the C11. Those of you that have a C11 on a CGEM do you find the mount capable? chip

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gatsbyiv
sage


Reged: 03/29/09

Loc: Whitehouse Station, NJ
Re: CGEM: What's the truth? new [Re: tedbnh]
      #3716845 - 03/31/10 01:48 PM

I bought mine used on a-mart, and I love it. Specifically:

- I'm set up and polar aligned in 15 minutes. The All-Star polar alignment alone is worth the price of admission. By the third night out, I had settled into a routine and understood the controller and options available reasonably well.

- Gotos are dead-on.

- The improvement in my imaging (autoguided) was dramatic (upgrading from LXD75), not only in terms of tighter stars, but also in terms of less subs thrown out.

- I've had no glitches or error messages in three months of use.

- The ability to guide past the meridian is a plus, since I'm usually long asleep by this time, and it gets me 40 minutes or so of additional exposures.

- As for upgrades, I got the scopestuff Losmandy adapter. The ADM saddle is surely nice, but extremely expensive.

- I don't see what all the complaints about the CGEM's knobs are about. They work fine for me; sure, they could be improved, but it hardly seems like a priority upgrade.

I'd be *BLEEP* too if mine had some of the glitches I've heard others here complain about, but so far, mine has been a real workhorse.


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RTLR 12
Post Laureate
*****

Reged: 12/04/08

Loc: The Great Pacific NorthWest
Re: CGEM: What's the truth? new [Re: gatsbyiv]
      #3717175 - 03/31/10 04:25 PM

I've had mine for 5 months now and average 10 to 15 nights a month viewing. For a $1300.00 mount I am pleased and I have not had any surprises nor do I have any complaints. I have set up in the field for as long as 10 days and only had to tweek the alignment because the go to's weren't quite centered in a 6mm EP after 4 days. If I had spent $6000.00 on a mount I would expect it to peform like $6000.00. The CGEM performs as it should.

Stan


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bob midiri
Carpal Tunnel
*****

Reged: 06/17/04

Loc: pa 19320
Re: CGEM: What's the truth? new [Re: gatsbyiv]
      #3717674 - 03/31/10 09:09 PM

Yeh I decided to do the same and get the Scope-stuff adapter and the extended chord for the HC. Like you the nobs don't bother me a bit. Bob

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jbattleson
Happily Retired
*****

Reged: 03/02/09

Loc: Nebraska
Re: CGEM: What's the truth? new [Re: glennstevens]
      #3717728 - 03/31/10 09:55 PM

I have the C11 on mine and it is very stable. I have even done some AP with it but think the C8 would be better choice if AP was your main objective.

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microstar
Pooh-Bah


Reged: 01/05/08

Loc: Canada
Re: CGEM: What's the truth? new [Re: jbattleson]
      #3718399 - 04/01/10 09:44 AM

Great thread, as I am looking to replace the frustration level of my LXD75. A few imaging questions that haven't been asked:

1. What is the periodic error, and how smooth is it (i.e. is it easily guided out)?

2. What is the maximum load for imaging? My SN8 with piggy-backed ZS66 and camera gear is pushing the 40lb limit. Can it really image with a 40lb load and still track smoothly, or would that require the big bucks for a CGEpro?

...Keith


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SanDiegoPaul
Carpal Tunnel
*****

Reged: 07/22/05

Loc: San Diego
Re: CGEM: What's the truth? new [Re: microstar]
      #3719257 - 04/01/10 04:21 PM

Quote:

Great thread, as I am looking to replace the frustration level of my LXD75. A few imaging questions that haven't been asked:

1. What is the periodic error, and how smooth is it (i.e. is it easily guided out)?

2. What is the maximum load for imaging? My SN8 with piggy-backed ZS66 and camera gear is pushing the 40lb limit. Can it really image with a 40lb load and still track smoothly, or would that require the big bucks for a CGEpro?

...Keith




RE: Periodic Error = my CGEM had 13 or so out of the box. PemPRO knocked that down to 2.5 Arc Seconds in one swoop.

RE: Max Load for photography - the general rule is to use a mount at half it's rated capacity if you are imaging. So that would put us at a 20# rating for photog work.


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RobertinTucson
newbie


Reged: 04/01/10

Re: CGEM: What's the truth? new [Re: R Nitzel]
      #3719930 - 04/01/10 11:50 PM

I feel your pain. The new CGEM I just ordered arrived Tuesday this week, only not to work straight out of the box. Later that night I was able to trace the problem to a bad encoder board on the dec motor. (BTW - if the mount periodically slews on a particular axis, or if you can't get the slew rate to slow down on a particular axis, suspect a loss of encoder signal). I've contacted Celestron to see if they'll send me a new dec motor assembly, but haven't heard back from them after the initial call. I like the mount mechanically, but at the moment I've got an 80-pound boat anchor.

Best of luck to you.


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Lane
Post Laureate


Reged: 11/19/07

Loc: Frisco, Texas
Re: CGEM: What's the truth? new [Re: JadeSmith]
      #3720152 - 04/02/10 05:00 AM

Love my CGEM. Now 15 months old. The saddle is the real weak point on the mount and I replaced mine with the ADM version made specifically for the CGEM.

I had one minor issue with mine not finding alignment stars on a night a few months ago. It didn't even point to the right constellation, but it only happened that one time and the solution was just to use the arrow keys to point the scope to the correct stars and all was fine after that.

Another issue I have seen reported and experienced myself a few times is the run-away declination problem where the mount seems to get confused and one of the motors continues to slowly move the scope and does not stop after a GOTO command. It happens only when the object is near the meridian and in the southern direction. The problem is that the electronics should have moved the ota to the other side of the mount during the GOTO, but they don't and then the OTA cannot reach the object because of the slewing limits that protect the OTA from hitting the mount. The solution is just to cancel to GOTO and use the arrows to move the ota to the other side of the mount manually then repeat the original GOTO. Works fine after that. This can also happen when an object is well past the meridian if it has been several hours since you aligned the mount. Apparently it does not keep track of the meridian very well as the night progresses unless you re-align or replace the alignment and calibration stars after about 4 hours of use.

The CGEM is pretty stable with a C11 on board and even works well in mild windy conditions. The C8 is a ROCK on the CGEM, even strong wind hitting the OTA has little effect.


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SanDiegoPaul
Carpal Tunnel
*****

Reged: 07/22/05

Loc: San Diego
Re: CGEM: What's the truth? new [Re: Lane]
      #3720622 - 04/02/10 12:01 PM

Quote:

Love my CGEM.

The CGEM is pretty stable with a C11 on board and even works well in mild windy conditions. The C8 is a ROCK on the CGEM, even strong wind hitting the OTA has little effect.




Nice. Using just my Stellarvue Raptor-90 on the CGEM without a large OTA, I should be able to do 30-minute image subframes. I can't wait for this last burst of junky weather to go away so I can test this out.

I have done 10 and 15 minute subs very easily.


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waassaabee
Postmaster
*****

Reged: 11/26/07

Loc: Central California Coast
Re: CGEM: What's the truth? new [Re: SanDiegoPaul]
      #3720651 - 04/02/10 12:12 PM

Quote:

Quote:

Great thread, as I am looking to replace the frustration level of my LXD75. A few imaging questions that haven't been asked:

1. What is the periodic error, and how smooth is it (i.e. is it easily guided out)?

2. What is the maximum load for imaging? My SN8 with piggy-backed ZS66 and camera gear is pushing the 40lb limit. Can it really image with a 40lb load and still track smoothly, or would that require the big bucks for a CGEpro?

...Keith




RE: Periodic Error = my CGEM had 13 or so out of the box. PemPRO knocked that down to 2.5 Arc Seconds in one swoop.

RE: Max Load for photography - the general rule is to use a mount at half it's rated capacity if you are imaging. So that would put us at a 20# rating for photog work.




I'm running a little under 30# @1625mm on mine and it does just fine. Seven minute subs guided, and could probably go to ten (I just haven't tried it).


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MikeS
Pooh-Bah


Reged: 04/06/04

Loc: Quakertown Pennsylvania
Re: CGEM: What's the truth? new [Re: tedbnh]
      #3768422 - 04/25/10 09:08 PM

Quote:

So, I shipped it off to Tom Hadoulias at Astro Motion Technologies for his tighten-up tune-up...




Ted, what is your opinion of the Astro Motion Tecnologies upgrade?


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wb9sat
sage


Reged: 06/16/09

Loc: Bend, Oregon USA
Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3768510 - 04/25/10 09:53 PM

Hi All,
I am finding this thread most interesting. I just received my new CGEM and haven't had a chance to turn it on yet. It seems that Orion's EON 120ED dovetail does not fit the CGEM so I had to order a new dovetail from Losmandy today. The reports of this mount are encouraging. I was told that this was the best mount in its class. I can't wait to try it.
Bill


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PhilCo126
Post Laureate


Reged: 01/14/05

Loc: coastline of Belgium
Re: CGEM: What's the truth? new [Re: wb9sat]
      #3768938 - 04/26/10 05:37 AM

I’ve bought my CGEM new from TS in Germany one year ago and set it up about twice / thrice each month without any problems!
Bringing it outside, loading the refractor and polar alignment is done in 15 minutes. The All-Star polar alignment alone is worth the price of admission.
No problems nor glitches in 12 months of use and the CGEM knobs seems O.K. for usage in the dark or in cold weather. The ADM upgrade knobs look great in orange color but I don’t know if each of those is available loosely for purchase (e.g. especially the DEC + RA clutch knobs in orange color to find these easier in the dark )


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kevc
Pooh-Bah
*****

Reged: 03/22/10

Loc: Long Island NY
Re: CGEM: What's the truth? new [Re: PhilCo126]
      #3769502 - 04/26/10 01:01 PM

I have had the typical HC issues. It would not update through the USB>serial cable. Went around and around with Celestron about it, after three different cables and multiple chats with the tech dept, they finally are sending me a new HC. Don't have it yet, but I will report back when it comes in. The tech dept is NOT the easiest bunch to deal with, the assumption is that the customer is the idiot and that nothing could be wrong with a piece of Celestron equipment. Hope they prove me wrong in the future.

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RWFAPEX
member


Reged: 12/04/07

Re: CGEM: What's the truth? new [Re: jrbarnett]
      #3770031 - 04/26/10 05:50 PM

Hello all. I am doing a Critical Evaluation on the CGEM EdgeHD 800. If you join the Yahoo!Groups for CGEM you can see my Parts I through IV synopsis. One last set of tests to run (auto meridian flip, wind limits, AllStar Polar Align precision & accuracy) but right now I'd give the CGEM a thumbs up for imaging.

In short, PEMPRO and K3CCD Tools-measured PE was 28 peak-to-peak. Sounds horrible but the amplitude swings are smooth; thus, in no wind, at 2032 mm, I'm able to guide 10 min subs. Due to LP here in Raleigh, NC, I usually stay around 5 mins or less. At 300 seconds, I have anywhere from 75 to 95% sub 'save rate' depending on sky location of target. For $1,400, right out of the box - amazing! Understand I've owned CG5, LXD55/75, Sirius, Atlas (2), G-11 and my current AP900GTO (I'm not going to mention all the CPCs and LX scopes either - lots let's say)!

I did have a runaway Dec incident with new mount. In my case, I traced it to a shorted RJ-11 filament down inside the female on-mount connector. Simple fix but took four hours to find! I've also learned the mount cannot tolerate less than 11.8V - no exceptions during a slew or mount goes bonkers. Since I have discovered both issues, others from all over the world have written to report same issue and all are happy they can resolve themselves.

I may do my own article for Cloudy Nights soon. Lots I didn't report in Yahoo!Groups on EdgeHD particulars as well. Hope this helps.


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tedbnh
scholastic sledgehammer


Reged: 11/14/07

Loc: New Hampshire
Re: CGEM: What's the truth? new [Re: MikeS]
      #3770639 - 04/26/10 11:13 PM

Tom H. still has my CGEM and is communicating several times a week, with long notes and photos of the interior parts. Sometimes I feel like I am following along on an operation by an experienced surgeon. He has found some interesting stuff and wants to keep working on it so I said go ahead. I feel the mount is at the place where it can get the best overhaul possible. Note I have no connection to Tom and have formed this opinion solely upon his communications to me over the last few weeks which have been excellent.

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MySchizoBuddy
member


Reged: 04/22/10

Re: CGEM: What's the truth? new [Re: tedbnh]
      #3771107 - 04/27/10 08:52 AM

Does the mount come with PemPRO or any other software for control and PEC

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Chris Rowland
professor emeritus


Reged: 02/28/05

Re: CGEM: What's the truth? new [Re: MySchizoBuddy]
      #3771287 - 04/27/10 10:33 AM

Celestron's free PECTool software is available for the download. It isn't as feature rich as PemPRO but does the basics of automating collecting multiple PEC cycles, averaging them and loading the result to the scope.

It also allows the PEC data to be archived on the PC so if you need to do a factory reset or update your HC or MC you can reload your hard won PEC.

Chris.


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kpendlebury
Vendor Main Sequence Software


Reged: 11/12/08

Loc: Central TX
Re: CGEM: What's the truth? new [Re: Chris Rowland]
      #3772049 - 04/27/10 04:18 PM

I have had my CGEM for about 10 months now and have take quite a few images with it at short FLs (http://www.flickr.com/photos/kenastro/). Based on testing and use, I would be a little timid about using the CGEM for imaging at longer focal lengths. My peak to peak PE comes in at about 43 arc seconds (I have seen reports up to 55 - 60 arc-seconds) and seemed to train out well coming in a 6.3 arc-seconds peek to peek. I am not complaining here... for $1400 this mount performs admirably.

Obviously, the blue curve is corrected and the red curve is out of the box PE:



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rmollise
Postmaster
*****

Reged: 07/06/07

Re: CGEM: What's the truth? new [Re: kpendlebury]
      #3772151 - 04/27/10 05:15 PM

Quote:

I have had my CGEM for about 10 months now and have take quite a few images with it at short FLs (http://www.flickr.com/photos/kenastro/). Based on testing and use, I would be a little timid about using the CGEM for imaging at longer focal lengths.




6.3 arc-seconds without guiding and you would be timid to use it at longer focal lengths? Why?


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Trox
journeyman


Reged: 01/26/10

Loc: Denmark
Re: CGEM: What's the truth? new [Re: tedbnh]
      #3772283 - 04/27/10 06:27 PM

Quote:

Tom H. still has my CGEM and is communicating several times a week, with long notes and photos of the interior parts.




Hi tedbnh,
Care to share some of those pic's of the interior of the CGEM? I'm about to buy a CGEM, but stumbled across some post about the gear's material (Gearbox).
/Trox


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Jeff55
professor emeritus


Reged: 04/14/05

Loc: Boston MA
Re: CGEM: What's the truth? new [Re: SanDiegoPaul]
      #3772463 - 04/27/10 08:01 PM

I've got mine loaded to almost maximum capacity and it just works. Even fit and finish is excellent. In its' price range it is absolutely unbeatable. I love it!

Edited by Jeff55 (04/27/10 08:18 PM)


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kpendlebury
Vendor Main Sequence Software


Reged: 11/12/08

Loc: Central TX
Re: CGEM: What's the truth? new [Re: rmollise]
      #3773633 - 04/28/10 01:08 PM

Quote:

6.3 arc-seconds without guiding and you would be timid to use it at longer focal lengths? Why?




You have a fair point Rod. My problems are likely not mount related, but rather user related. I still have trouble with exposures greater than 5 minutes, but this might be due to my own inexperience, polar alignment issues or with differential flexure.


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Bart
Carpal Tunnel
*****

Reged: 05/28/06

Loc: Somewhere near Charlottesville...
Re: CGEM: What's the truth? new [Re: Chris Rowland]
      #4329786 - 01/21/11 01:18 PM

Interesting thread. Thanks Jim.

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Ad Astra
professor emeritus
*****

Reged: 05/12/10

Loc: Riverside Co., California
Re: CGEM: What's the truth? new [Re: Bart]
      #4330002 - 01/21/11 02:50 PM

I have a CGEM-11 at work for the kids to use in astronomy class. It works great and tracks fine. We don't do a lot of astrophotos on it, though - so I can't say much about photographic performance.

Fit, finish, and reliability have been fine over the last 18 months, and as you may imagine with it being a 'school' instrumnet, it doesn't always get treated with the utmost care it deserves.

Overall, I've been really pleased, and for visual work, I'd recommend one to a friend or buy one again.

This being said, the mount is about at it's limit for weight with a C11. I've mounted my big refractor (40+ lbs, f/12 monster) and it causes the mount to strain and the wobble and vibration dampening to shoot through the roof to totally unacceptable levels.

Dan


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