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CG5 RA Axis Works Loose Occasionally

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#1 _Z_

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Posted 09 May 2011 - 07:13 PM

I've tweaked my CG5 ASGT quite a bit but I find that the RA Axis, the one that I really have to have just right so my autoguider will play nicely with it, tends to lose that just setting a little too easily.

On at least 2-3 different occasions whether it's from transporting it or doing something with the scope that is mounted on it, the RA clutch is locked down tight and some force ends up being put on the RA axis because of whatever else is going on, and it manages to move some even while locked down, loosening up the worm gear and introducing a noticeable amount of slop.

After that happens, even if locked down, the mount can wobbly back and forth a short distance, enough to completely ruin autoguiding and the several nights worth of work to tweak it just right.

I have to fix my RA axis yet again before a star party at the end of the month and i'm wondering if there's anything that I should be checking for why it works loose so easily? I don't mean to apply pressure to the axis when it's locked, but maybe it's working loose too easily?

Thanks,
Jeremy

#2 Geo.

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Posted 10 May 2011 - 08:36 AM

Are you tightening the set screws that lock the RA axle ring nut?

#3 RTLR 12

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Posted 10 May 2011 - 08:44 AM

Remove the clutch lever from the shaft and rotate it counterclockwise one notch and then reinstall it. This will give you more adjustment on the tension of the clutch.

Stan

#4 _Z_

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Posted 10 May 2011 - 10:06 AM

Are you tightening the set screws that lock the RA axle ring nut?


Are you talking about the ring nut in the 3rd picture on astronomy boy's instructions?

http://astronomyboy.com/cg5/ra.shtml

I really haven't done much with that part of the axis, the main part I adjust is the worm gear, so it engages just enough with basically no slop, so the autoguider can be responsive without slop or resistance.

#5 _Z_

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Posted 10 May 2011 - 10:06 AM

Remove the clutch lever from the shaft and rotate it counterclockwise one notch and then reinstall it. This will give you more adjustment on the tension of the clutch.

Stan


I thought I heard if you tighten the clutches too much, an autoguider won't be able to move the axis very easily?

#6 RTLR 12

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Posted 10 May 2011 - 10:38 AM

An autoguider controls the motors on the mount to maintain alignment on the target. The motors are connected to the worm drive gear via a spur gear. The worm drive gear is meshed to the ring gear that rotates the mount on the axis. The clutch locks the mount axis and the ring gear together. It has no direct correlation to the autoguider's ability to control the mount. It is only a lock between motor drive and mount.






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