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

[StarGazingSiouxsie]

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. 

Siouxsie 

Edited August 24, 2020 by StarGazingSiouxsie

[Starwatcher2001]

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.

[StarGazingSiouxsie]

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.  

[stargazer27]

On 22/08/2020 at 23:28, StarGazingSiouxsie said:

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. 

Siouxsie 

I just wanted to thank you for this, so much. My first Celestron 11” had a problem when installing the motorized focuser that shredded the gasket under the bearing. I reluctantly sent it back for warranty service. I received my second one (which I had to wait 2.5 months for) and attempted to install the focuser and had the binding problem. I investigated the bearing and saw that it appeared to be slightly higher on one side, contacted support, and was about to send another one back out AGAIN. That would make 7/9 Celestron products that required RMA or support. Their quality control is just poor, and they really don’t care. Anyway, you saved me probably two months of waiting. I appreciate it very much. Now I have to RMA a brand new CGX, CGEM II and a Sky Portal. :/

[Surfjumper]

I ran into the same issues. I couldn't seat the Cel. Focus Motor properly on my Evo 9.25. After reading everyone's posts I found the optimal solution. I'm shocked Celestron can't figure this one out, and recommend, but it's quite easy once you know what to get.

Step 1: Replace the original cover plate that came with the scope.

Step 2: Place whichever new cover plate required for your scope on top of the original cover plate.

Step 3: Run down to Ace Hardware and buy three (3) M3x0.5x10mm metric socket head screws. (Be sure you have a 3mm socket wrench). I bought mine for $0.27/piece at Ace. Edmonds optics offers a pack of 5 for $6.00. Here's a link for those that would like to order direct: https://www.edmundoptics.com/p/m3-x-05-x-10mm-l-socket-head-cap-screw-pack-of-5-/28329?gclid=CjwKCAjw2f-VBhAsEiwAO4lNeOpotb68msz8rXfzDvYbGLZ6Rryv-n358vGZUYbcvD8xV8tk_rw5jBoC0UsQAvD_BwE

Step 4: With the original cover plate aligned properly with the screw holes, place an equally aligned scope plate (the one that came with the motor that adapts to your scope) on top of that. Then use a 3mm socket wrench to work each of the three screws into place. Twist it slowly, until it goes snug, for each screw in turn, then tighten each up snug. You will enjoy the experience of feeling a snugged up screw and that sense of "omg, this actually was designed properly!" That's the feeling that Celestron has been robbing each of us who've purchased this device... until now. 

Step 5: Continue with the rest of the installation with total ease at this point. Everything will lock down nice and firmly.

That is LITERALLY all you have to do. If you use the screws I specified above, they will tighten down perfectly. If you wanted to work some Threadlocker into the screw holes, you can, but I haven't found the need and I've been using it for several nights in a row now... Unfortunately, in Orange County that means focusing on clouds, but the motor worked perfectly, without a hitch. 

In reality, this is actually a more effective fix than what Celestron shipped, and using this approach is inherantly better for mounting against this bearing. As was written up pretty well by another fellow, the bearing is not flush with the rest of the housing. It protrudes approximately 1mm out, poking its little neck up enough to make screwing in the three provided crews a completely impossible task. On the reverse side of the original cover plate, there is a recession of approximately 1mm that is finely milled into the cover plate. By keeping this in place, the bearing is able to rotate, ever so slightly, within that milled space. I think most engineers would agree that this is the far superior solution for this product as all they would have to do is change the screws they ship, and change the instructions. 

 

Not quite sure Celestron doesn't just ship the scopes with three extra socket head screws for less than $1, with no returns, and full satisfaction.