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Celestron Focus Motor install problems and solutions for a CPC1100 (and likely other 11" & 14" OTAs, too.)

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Posted (edited)

Celestron Focus Motor install problems on a CPC1100

I've read enough threads online to know I'm not the only person to encounter problems with installing the Celestron Focus Motor.  Despite following the install instructions to the letter and watching a load of videos on how to do this, I could not get the motor work correctly with the screws for the mounting plate and motor mount installed anything other than loosely - which is obviously not right.

I read up on a lot of threads about this and it seems the basic problem is that the mounting plate supplied with the motor causes pressure to be put on the focus bearing and thereafter causes binding and locking up. People have come up with many solutions including installing washers / shims and, taking Celestron's Tech Support advice, to install the orginal focus mounting plate first and then the Focus Motor kit mounting on top. - and that's what I did. 

Whether by luck or design, Cubble came with quite long screws in his original mounting plate so there was ample thread left to pass through both plates. 

With both plates installed, all the screws can now be tightened down (snugged down, nothing OTT), including the 2 hex screws for the motor mount. Before, the screws had to be left loose just to allow the motor to turn and, believe me, I spent hours making sure everything was true and aligned correctly to try and solve this.

Anyway, that's what worked for me and I am happy that my motor is now working as intended. Celestron are a strange set up - they produce great scopes but some of their kit and accessories leaves a lot to be desired, from a R&D point of view.

I hope this may help someone else out down the line. 


Edited by StarGazingSiouxsie
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Thanks for that. I've had the focus motor on order since mid July. When it finally arrives, your post may well be invaluable. I'll let you know how I get on with it.

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1 hour ago, Starwatcher2001 said:

Thanks for that. I've had the focus motor on order since mid July. When it finally arrives, your post may well be invaluable. I'll let you know how I get on with it.

Note that there are 2 plates in the kit - one for OTAs up to 9.25 and the other for the 11 & 14s. 

I'm not sure if your mounting plate screws will be long enough if you wanted to try to the 2 plate method but you can see.

Anyway, I hope it won't come to that and that your install is problem free. :) 

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