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CGEM -- first impressions

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#1 amys

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Posted 02 May 2011 - 04:05 PM

A fellow club member just got a new CGEM last week and I got to help him set it up and assist him in his first 2-star alignment. I have a CG-5, which I haven't used in a few years, so I was familiar with the basic desgin and the software.

I have to say that I was quite impressed with the mount. It's quiet, fast and our first 2-star align with only 1 calibration star produced very good go-tos. Right out of the box. Our polar alignment consisted of our setting the tripod down and eyeballing true north with my compass in my hand, offset for our declination. We did not go through the polar alignment routine. It's a good thing the mount is too heavy for me or I'd be tempted to sell my Vixen SXW and buy one. :grin:

It does have me seriously considering ordering the NexSXW board so that I can use the Celestron software and CG-5 hand controller with my Sphinx. While I really like the design of the Sphinx (the hardware is much more solid than the CG-5), the Celestron software is clearly superior.

#2 BCB

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Posted 02 May 2011 - 06:52 PM

Next go round, do a three star with one calibration star.. It'll work even better.. LOVE mine.. :)

Three star removes cone error..

#3 amys

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Posted 02 May 2011 - 07:24 PM

I'll remember that. And I'll pass it along to the owner.

#4 deepskyguy

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Posted 02 May 2011 - 10:46 PM

Sorry if this is common knowledge but how do you do 3 star alignment? I can only find info on 2 star plus calibration. I looked through the manual and couldn't find it...

#5 clchildress

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Posted 03 May 2011 - 06:01 AM

I found that a two-star alignment with three calibration stars produced deadly accurate go-to performance for me. Glad you like the CGEM; I'm absolutely loving mine so far.

#6 Javier

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Posted 03 May 2011 - 10:16 AM

I'm looking forward to buying one as well for my C6R.

#7 biggles

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Posted 03 May 2011 - 12:45 PM

:cool:Loved my MeadeLX90 10" so much I bought it a CGEM for it's birthday!! :bigshock: :waytogo: :band: :bounce: :FarmerRon: :photo: :whee: :drool5: :lalalala: :bow: :jump: :grin: :D

#8 Helcarexe

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Posted 03 May 2011 - 01:07 PM

I'm looking forward to buying one as well for my C6R.


+1 for a C6R also

#9 jrbarnett

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Posted 03 May 2011 - 02:43 PM

I had a chance to play with a CGEM at the last club star party. I fielded an Atlas. It was nice to see both mounts in action at the same time.

The CGEM is better finished, and much more ergonomic than the Atlas. It goes without saying that the Nexstar firmware is light years ahead of Synscan on the feature front. The CGEM also slews to targets MUCH faster than the Atlas (I'd estimate >2x the slew rate).

On the other hand, the CGEM is much noisier in operation than the CGEM, and the particular unit we were using suddenly bound up in its declination axis during the session. It had been "hypertuned" professionally, and I suspect something had been either meshed too tightly or left too loose. By the cold light of day the owner discovered that the declination worm adjustment screws were loose, and tightening them fixed the glitch. Whew!

My Atlas hasn't missed a day of school since I bought it many years ago.

I really liked the CGEM and if I was going to refresh my aging Atlas, I'd definitely consider it. My only misgiving is the less than stellar reliability reports and my own observed failure of the unit I had the opportunity to use.

Regards,

Jim

#10 hfjacinto

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Posted 03 May 2011 - 02:53 PM

I have the CGEM and while the first one was defective the second has worked very well. I am even able to image with the 9.25 which in itself is a large feat considering with cameras, guide scope etc. I am pushing 35lbs.

Mark (BCB),

How do you do 3 star alingment?

#11 BCB

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Posted 03 May 2011 - 03:04 PM

It's been awhile since I've fired mine up.. I MAY be thinking of a two star plus calibration.. I wasn't 100% certain when i posted that.. :lol: With the weather we've gotten up her (as you well know Helder) I haven't had many opportunities to actually use the darn thing..

I CAN say adding more calibration stars does make the alignment deadly accurate.

#12 hfjacinto

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Posted 03 May 2011 - 03:14 PM

I use 2 star alingment and 4 star calibration but thats becuase when imaging having the DSO in the center of FOV is much easier to image when you don't have an eyepiece to look through :)

#13 amys

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Posted 03 May 2011 - 04:59 PM

I have the CGEM and while the first one was defective the second has worked very well.

Mark (BCB),


Mark:

What kind of issues did you have with the first one?

#14 mistyridge

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Posted 03 May 2011 - 06:06 PM

I liked mine so much I am selling it to share the wealth. :whistle: :money:

#15 BCB

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Posted 04 May 2011 - 04:35 AM

I have the CGEM and while the first one was defective the second has worked very well.

Mark (BCB),


Mark:

What kind of issues did you have with the first one?


It was actually hfjacinto who posted that.. :lol: I was sitting here trying to figure out WHERE i put that in this post and had to re-read the whole thing to find it.

For me, the biggest thing that popped up was one error 17 that happened the second night i used it.. I was able to back out of it completely (undo key), and the mount kept the alignment and never skipped a beat.

I'm not completely sure, but I think he suffered from the dreaded error 17 issue as well..

#16 amys

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Posted 04 May 2011 - 05:36 AM

Sorry 'bout that. :foreheadslap:

An issue developed the other night after I left where the mount stopped finding objects and responding to the directional arrows. They ultimately got it going again. I was just curious to know if there are certain common issues that tend to crop up with these mounts.

I didn't run into any problems at all using my CG-5 except for my bonehead tendency to hit the "enter" key instead of the "align" key while doing my alignment. :p

#17 Swamp Fox

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Posted 04 May 2011 - 06:35 AM

Another satisfied customer here! I have had my CGEM for less than 2 weeks and have used it 5 nights with both the 4” and 9-1/4”. So far using 2-star alignment +1 calibration star, it is dead on when moving from object to object.

#18 Bart

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Posted 04 May 2011 - 07:52 AM

Which brings me to my conundrum. Should I upgrade to the CGEM DX or the Losmandy G11/G2? I'd save 1200 bucks going with the CGEM, but I'd gain 10 more pounds of weight capacity if I went with the G11. This is a Buridan's @ss dilemma for me.

#19 gdd

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Posted 04 May 2011 - 08:25 AM

Which brings me to my conundrum. Should I upgrade to the CGEM DX or the Losmandy G11/G2? I'd save 1200 bucks going with the CGEM, but I'd gain 10 more pounds of weight capacity if I went with the G11. This is a Buridan's @ss dilemma for me.



You would also gain more precision with the G11. How do you plan to use it? That would determine whether it is worth it to spend more.

Gale

#20 jrcrilly

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Posted 04 May 2011 - 08:30 AM

Which brings me to my conundrum. Should I upgrade to the CGEM DX or the Losmandy G11/G2? I'd save 1200 bucks going with the CGEM, but I'd gain 10 more pounds of weight capacity if I went with the G11. This is a Buridan's @ss dilemma for me.



You would also gain more precision with the G11. How do you plan to use it? That would determine whether it is worth it to spend more.

Gale


Yup. I'd rather image with the G11 but I'd prefer to carry a CGEM around for visual use in the field.

#21 hfjacinto

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Posted 04 May 2011 - 08:38 AM

Amys,

The first CGEM I had the following issues:
1) Way too much slop, the mount would move an inch in alt and dec.
2) One of the screws was stripped on the housing
3) Part of the mount housing was cracked
4) Motor Fault errors.

The best I can tell was that the mount was dropped and something broke inside. As soon as I tried it the first time, I knew something was wrong. It would tick, tick, tick, tick while tracking. When I started looking at it, I saw the crack, the stripped broken screw and realized the mount was damaged. OPT took really good care of me, so if you buy from a good dealer, you should have no issues.

The second mount has worked well for almost a year and tracks very well.

Attached Files



#22 Helcarexe

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Posted 04 May 2011 - 08:43 AM

Nice image it does look like the mount is working, its good to hear that a dealer will take care of its customers.

#23 AntarcticDave

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Posted 04 May 2011 - 09:00 AM

I have had mine for a bit over 2 years and it's still working just fine.

#24 EFT

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Posted 04 May 2011 - 09:32 AM

I had a chance to play with a CGEM at the last club star party. I fielded an Atlas. It was nice to see both mounts in action at the same time.

The CGEM is better finished, and much more ergonomic than the Atlas. It goes without saying that the Nexstar firmware is light years ahead of Synscan on the feature front. The CGEM also slews to targets MUCH faster than the Atlas (I'd estimate >2x the slew rate).

On the other hand, the CGEM is much noisier in operation than the CGEM, and the particular unit we were using suddenly bound up in its declination axis during the session. It had been "hypertuned" professionally, and I suspect something had been either meshed too tightly or left too loose. By the cold light of day the owner discovered that the declination worm adjustment screws were loose, and tightening them fixed the glitch. Whew!

My Atlas hasn't missed a day of school since I bought it many years ago.

I really liked the CGEM and if I was going to refresh my aging Atlas, I'd definitely consider it. My only misgiving is the less than stellar reliability reports and my own observed failure of the unit I had the opportunity to use.

Regards,

Jim


Just a note on this mount. If it is the mount I think it is, the owner got it second hand after the original owner had made some adjustments and apparently either left the bolts loose or they somehow got loose in shipment. They were not loose from the service on the mount and it was not a defect in the mount. This mount has also been shipped very long distances including to Canada and mounts that travel like that may frequently need fine adjustment afterwards to account for environmental changes, especially if the mount has been previously fine tuned to remove as much backlash as possible. Again, it is not a defect in these mounts, just a fact of life.

#25 jmiele

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Posted 04 May 2011 - 10:40 AM

IMO, shipping mounts and telescope long distances is a fact of life. If manufaturers are making gear that cannot be shipped and still perform to a certain level, then that is a problem. Upon arrival, ANY of the gear from ANY maker, should perform to the documented spec. And it's NOT the carriers fault. We too often want to blame UPS and FEDEX. Poor design and packaging are the main reason things arrive out of spec. Can you ship Eggs via UPS.....? Sure you can, but not in the catron you buy at the supermarket. But as we learned in school, you can make a carton or package to support dropping the egg from the 2nd floor window without it breaking. Telescope and mount makers need to make gear and packaging the can live within the current delivery systems because we aren't going to pick everything up at the shop :)

3,4 maybe 5 cents :)

Joe






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