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CGEPro Problem

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#1 LLEEGE

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Posted 21 June 2010 - 11:24 AM

Serious DEC axis issues for me to return my club's mount to Celestron for repair. There is so much play in the DEC axis, we can't get 30 sec exposures without "double" stars. :(
Good news is, Celestron is picking up the shipping costs. I hope they can get the mount working properly. I encouraged the club to spend the $$ on it. :foreheadslap:

#2 David Pavlich

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Posted 21 June 2010 - 12:54 PM

Well let's hope it's just a matter of adjustments. Any idea how long it'll take? I'm sure there's a bunch of Pro owners that will watch this very carefully.

David

#3 nofxrx

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Posted 21 June 2010 - 07:28 PM

Hey Luke!
I am not sure about the DEC issues with the CGE PRO. but my good friend Terry Hancock(CN id:turbo399,or on my HyperCams Y!Group) sent his entire RA assy to a machinist in Alaska,and he performed a spring loaded worm mod to the housing..he has been getting PERFECT stars at ~1"pixel image scale.never any issues with DEC however..
Before the mod,he was scratching his head at this mount, and regretting the purchase for some time..and his images had fairly obvious double star, or drift.
He tried everything..now, it is only the weather holding him(and most of us..) back from imaging!

I am saying this because it seems that these mounts are hit and miss...I am hoping your club's is a simple fix!!! AND that they do it quickly,but do it right, before sending it back!!
It was NOT a bad decision to suggest this mount...if I had an OBS I would own one as well!
It is a PERFECT mount for the market in that price/capacity range...just needs a bit better QC maybe...

Good luck!!!

#4 Chris Rowland

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Posted 22 June 2010 - 02:30 AM

I think the CGE pro has a spring loaded Dec worm, for minimal backlash, and a fixed Ra worm, for better tracking.

Backlash is less of an issue on the Ra axis because it's always moving in the same direction, even when guiding.

Chris

#5 LLEEGE

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Posted 22 June 2010 - 07:10 AM

I think the CGE pro has a spring loaded Dec worm, for minimal backlash, and a fixed Ra worm, for better tracking.

Backlash is less of an issue on the Ra axis because it's always moving in the same direction, even when guiding.

Chris

That is correct. However, no adjustment would correct the problem on ours. I'm crossing my fingers that they fix it right and the mount will give us years of use. Our club is having our annual star party July 9-11th. The mount was going to be the centerpiece. I hope we get it back in time. If not, I'll have to provide my mount as a "loaner".

#6 jimegger

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Posted 23 June 2010 - 01:22 PM

Mounting an RA worm with a fixed position is not the best way to do it. There is always some eccentricity in the gear system as well as differential expansion and contraction of components. A major source of periodic error comes from these situations due to variable binding causing the system to speed up or slow down depending on whether the worm is getting tighter or more loose in the gear teeth. This will occur even if the worm and gear are perfect in tooth spacing. I ALWAYS spring load my worms in my personal drive systems and get excellent tracking without the hassle of constant adjusting and tinkering. The spring automatically does all the adjusting for me. It gets rid of backlash and binding in a well designed system.






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