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CGEM Cannot Align Properly PLEASE HELP!

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#1 Domerman

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Posted 14 August 2009 - 10:30 PM

I just purchased a used but like new CGEM to replace my CG5 and I am so furious right now with the problems I am having. I am very familiar with the new Celestron 4.15 version. I use a side by side configuration that points the scopes west when the index marks are aligned. So I chose west as the scope orientation and aligned the index marks, but the scope is pointing nowhere near the location of the objects...this is even occurring after I do the two star align and pick 3 calibration stars. My alignments are perfect because I use a CCD camera to assist with this. Also, when the CGEM is slewing to an object it pauses for a few seconds and then continues slewing. This is very strange and never happened with the CG5. With the CG5, I just left the scope orientation as "normal," pointed the scopes north disregarding the index marks and everything worked beautifully. I tried this initially with the CGEM, but it did not work. I've tried every variation of the orientation and still all the objects are waaaaaaay off point. What is going on here???? :confused: Was I screwed over by the guy that sold me the mount?

EDIT: Time zone, time, location, date were all set correctly...I checked many times.

#2 Domerman

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Posted 14 August 2009 - 11:41 PM

I just tried to align it several times with a single light weight scope from its "normal" position. Both index marks were aligned with the scope pointing perfectly at polaris, but still in the end the same result. Gotos nowhere near the target. I am majorly disappointed here. :bawling:

#3 Domerman

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Posted 15 August 2009 - 12:58 AM

I just looked at the index marks on my mount and compared them to the photos in the manual. It looks like one of my index marks for the dec might have been printed on the wrong side of the mount. In the manual, it shows the index mark on the front for dec, but on my mount it is on the back. Can anyone who owns a CGEM please tell me where the index marks on your mount are for the dec?

#4 snommisbor

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Posted 15 August 2009 - 01:22 AM

Index marks go on the back. If I remember I think in the manual the picture showed the scope on backwards with the knobs to tighten the dovetail on the right side of the OTA instead of the left if you are looking from the side with the eyepeice

#5 Domerman

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Posted 15 August 2009 - 01:37 AM

Well there goes that idea. Is it normal for the CGEM to pause for a few seconds while slewing in dec and then begin to slew again?

#6 David Pavlich

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Posted 15 August 2009 - 08:32 AM

Hey Steve...I would go into the menu and find the command that resets the mount to default which will probably be somewhere in California.

After resetting it, enter your information. I've done this with a couple of different mounts and it worked.

David

#7 Harold925

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Posted 15 August 2009 - 11:31 AM

Your dec index mark needs to be matching the ra index mark, with the saddled screws on the control panel side. Just release the dec clutch and turn the saddle to line up. Page 29 of the manual explains the Home Position, it will line up the index marks automatically for you when you select it from the hand control. Celestron could have prepared the manual better!

#8 Domerman

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Posted 15 August 2009 - 12:15 PM

Your dec index mark needs to be matching the ra index mark, with the saddled screws on the control panel side. Just release the dec clutch and turn the saddle to line up. Page 29 of the manual explains the Home Position, it will line up the index marks automatically for you when you select it from the hand control. Celestron could have prepared the manual better!


That's exactly how I lined the index marks up.

#9 Domerman

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Posted 15 August 2009 - 12:36 PM

Now whenever the mount tries to align to a star the RA moves in the correct spot, but the dec keeps rotating around and around endlessly while pausing every so often.

#10 jrcrilly

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Posted 15 August 2009 - 12:42 PM

the dec keeps rotating around and around endlessly while pausing every so often.


That's certainly not an alignment problem, and the initial position isn't relevant. The free running DEC indicates an open loop - the DEC encoders aren't being read. The most common causes are an internal connection problem or a bad power source. I've also seen the encoder itself (inside the motor housing) defective.

#11 Domerman

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Posted 15 August 2009 - 01:01 PM

the dec keeps rotating around and around endlessly while pausing every so often.


That's certainly not an alignment problem, and the initial position isn't relevant. The free running DEC indicates an open loop - the DEC encoders aren't being read. The most common causes are an internal connection problem or a bad power source. I've also seen the encoder itself (inside the motor housing) defective.


Is there anyway to fix this on my own, or is this pretty much a thing that only Celestron can do?

#12 Blixx

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Posted 15 August 2009 - 02:00 PM

Steve,
If you have the power cord from your cg5 I would try using it. I have a bad connection on the cord that came with the mount. So I tried the cord from my cg5 and have had no other problems.
Dan

#13 Domerman

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Posted 15 August 2009 - 04:06 PM

I use exactly the power cord from the CG5 and continue to have the same problems. Thanks for everyone's ideas. I appreciate the help.

#14 Harold925

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Posted 15 August 2009 - 05:36 PM

Hello Steve,

I'm very sorry to hear of your mount troubles. I've never experienced pauses during the slews so far. I wish that I could help you with the situation. I've only had my new CGEM for about a month now, but I guess I was lucky for it to perform out of the boxes. I feel that the manual could have been prepared with more accurate details, it seems that trial and error takes over at times. Hey, give Celestron Tech Support a call, hopefully they can give you a hand and get everything taken care of. This mount delivers great stability and performance. I checked your site and you deserve high priced equipment to satisfy!

Regards,

#15 Domerman

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Posted 15 August 2009 - 10:18 PM

Thanks for the comments Harold. Unfortunately, the person who sold me this mount from Astromart does not want to issue me a refund and I am probably about to file a dispute. This guy had great ratings and seemed like a professional, but is not willing to own up to the fact that the mount arrived to me damaged. It looks to be in great condition externally just as he had described, but internally something is clearly wrong. I hope to get this issue resolved before I go to my offshore studies in two weeks. This is a lot of money just to throw down the toilet for a student like myself. I was hoping to get some imaging in before my classes and do some when I come back during my breaks. Doesn't look like that is going to happen... :(

#16 CounterWeight

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Posted 15 August 2009 - 11:54 PM

This may seem from left field, but well intentioned. Seems you've narrowed it down to a dec problem. I'd open up the dec housing and take a really good look at connections and etc. I have had the same problem when the conx to the dec was shorted on 2 pins - was inside the conx housing and very difficult to see... after much exploration, I did find the problem, and was relatively easy to fix (there went my warranty) - so I think if impoortant enough - try and take a good look - maybe something relatively east to remedy? If cable swapping between the assys makes no change then I'd go the next linear step in the troubleshooting process.

The electronics in Celestron mounts are really extremely simple (and in ways also 'cheap') and lend to 'I think' easy troubleshooting due to the modularity and in some cases commononality of parts between the RA and Dec housings.

This will not help with your dispute with the seller and I do not know what you can count on from Celestron as you aren't the original purchaser. But with luck it get the mount up and 'doing it's thing'.

Best of luck to you.

#17 rmollise

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Posted 16 August 2009 - 03:38 PM

I use exactly the power cord from the CG5 and continue to have the same problems. Thanks for everyone's ideas. I appreciate the help.


Check:

1. The power receptacle on the mount. If the fit is not snug, spread toe pin halve apart gently (if your mount has them).

2. Change power sources...that is the first thing to do when troubleshooting. Switch batteries or try an AC source.

#18 Domerman

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Posted 16 August 2009 - 04:49 PM

REALLY BAD NEWS NOW! I tried to disassemble the mount to see what was going on and I removed all the allen screws, but was unable to make the mount head budge...so I screwed all those back on. Then, I unscrewed the circuit panel or whatever it's called using the four screws that are at the corners of the panel. I did not disconnect anything at all...and now the mount does not move in RA at all!! It kind of responds. I hear the gears trying to engage in RA, but it does not move. I did a reset and still nothing. I am seriously screwed here!!

#19 Taylor

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Posted 16 August 2009 - 05:31 PM

Well it sounds like either a trip under warranty to Celestron is one of your options, or a dispute with the seller. Sounds like a pretty shady seller to me, if I send a product to a buyer I feel they have an expectation for it to fully operate upon arrival and its my job as a seller to ensure this.

In my experiences PayPal is less than helpful with disputes, "buyer protection" doesn't really exist. Try claiming it as "product significantly not as described". If that doesn't work, hopefully you paid with a credit card as they have better buyer protection than PayPal.

#20 Domerman

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Posted 16 August 2009 - 05:41 PM

That's the thing...now this damage with the RA is probably my fault and I can't make a dispute about it. I am such a fool for touching the mount! Jeez. :bawling:

#21 Taylor

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Posted 20 August 2009 - 02:38 AM

So how did this situation pan out for you Steve?

#22 Lord Beowulf

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Posted 20 August 2009 - 11:41 PM

Now whenever the mount tries to align to a star the RA moves in the correct spot, but the dec keeps rotating around and around endlessly while pausing every so often.


This sounds kind of like the Southern Hemisphere bug (assuming it's moving slowly).

Beo

#23 Domerman

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Posted 23 August 2009 - 01:16 AM

So how did this situation pan out for you Steve?


Shipping it off for repairs... :tonofbricks:

#24 ROTAG

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Posted 25 August 2009 - 09:47 PM

I just bought a cgem brand new in australia and have the same problems In fact i cant even do a two star alignmen,the first stars dec is 180 deg. out the next star is okay the third is 180 deg. out and it goes on. my idex mark is on the back which is hard to see with scope mounted. The ouck alignment is marginly better getting to a bout 30 to 40 degreg, of targets,also in tracking mode set to eq south when power is turned off mode resets to off and has to be reset when power is turned on .Needless to say, it,s going back.
ROTAG

#25 Chris Rowland

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Posted 26 August 2009 - 01:50 AM

There was an alignment problem in the southern hemisphere, it's been fixed.Just update you HC.

Chris






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