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What's Wrong With My New CGEM?!?!?

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#1 JadeSmith

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Posted 07 August 2009 - 02:48 PM

I just finished putting together my new CGEM. It's a beautiful mount. I heard about how much quieter these are than the CG5's (which I sold to help fund this) so I powered it up and ran both the RA and DEC to hear the difference. With only the counterweight attached (no scope) the RA motor does not appear to powerful enough to turn more than 45 degrees before the weight of the CW is just too much for the motor to handle. Is balance SO important that the motor can't handle its own counterweight?

The DEC motor turns Ok, but it's clicking....loudly. Sounds bad.

I used both AC adapter and DC adapter with my freshly charged powertank to rule out power issues and both produce identical results.

What the heck? This was a factory sealed unit...

#2 Fred1

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Posted 07 August 2009 - 03:19 PM

Put a scope on it, balance it and try again. Then report back. I suspect that the motors are straining due to the lack any counterweight to the counterweights. But I might be wrong.

#3 deSitter

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Posted 07 August 2009 - 03:27 PM

I just finished putting together my new CGEM. It's a beautiful mount. I heard about how much quieter these are than the CG5's (which I sold to help fund this) so I powered it up and ran both the RA and DEC to hear the difference. With only the counterweight attached (no scope) the RA motor does not appear to powerful enough to turn more than 45 degrees before the weight of the CW is just too much for the motor to handle. Is balance SO important that the motor can't handle its own counterweight?

The DEC motor turns Ok, but it's clicking....loudly. Sounds bad.

I used both AC adapter and DC adapter with my freshly charged powertank to rule out power issues and both produce identical results.

What the heck? This was a factory sealed unit...


ARGH!! NEVER run a drive grossly unbalanced like this - you could burn it out and it will put enormous lapping frictional force on the gears. The motors are designed to smoothly drive a balanced (or nearly so) system.

-drl

#4 JadeSmith

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Posted 07 August 2009 - 04:06 PM

Ok, so I get it when it comes to the RA axis, but the clicking on the DEC axis? I'm going to have to make a dovetail to mount my scope until the one from scopestuff arrives next week... I'll balance it and try it again.

#5 JadeSmith

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Posted 07 August 2009 - 04:43 PM

Dovetail is made and scope is on the mount now. The RA is totally fine now. I wrongly assumed the mount was stronger than it is. It ~does~ need to be balanced :) The DEC still clicks on speed settings 8 and 9. Should I be concerned?

#6 JadeSmith

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Posted 07 August 2009 - 04:50 PM

Here's a pic.... she looks good. 1st light tonight. Posted Image

#7 rmollise

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Posted 07 August 2009 - 05:26 PM

With only the counterweight attached (no scope) the RA motor does not appear to powerful enough to turn more than 45 degrees before the weight of the CW is just too much for the motor to handle. Is balance SO important that the motor can't handle its own counterweight?


As the good doctor said, 'THEN DON'T DO THAT!' As was mentioned, you are lucky you didn't ruin something. Never run the drives this far out of balance.

#8 deSitter

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Posted 07 August 2009 - 05:41 PM

Dovetail is made and scope is on the mount now. The RA is totally fine now. I wrongly assumed the mount was stronger than it is. It ~does~ need to be balanced :) The DEC still clicks on speed settings 8 and 9. Should I be concerned?


Yes, it should not be clicking - I would immediately get an RA for it. Don't take it apart, the warranty will be void. Just to guess, a missing gear tooth allowing slippage as it passes could do it.

-drl

#9 JadeSmith

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Posted 07 August 2009 - 05:42 PM

I got it I got it.... :foreheadslap:

Can anyone comment on the clicking? It only happens at fast slewing speeds....

#10 donsinger1

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Posted 07 August 2009 - 11:22 PM

I do not know about clicking, but my DEC on my CGEM has always been noisy and grindy sounding like a CG5, but, it works and works well, so I don't fuss about it.

Try the mount first and see how it works. If it does, great. My DEC btw has become smoother over time and is a bit less chattery than at first.

Don






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