*resolved* Screw size for focus knob cover plate - C8

[Prathab]

I'm trying to install a Celestron autofocuser on an old C8 OTA. The 3 screws that hold the original cover plate are too short for the new cover plate included with the focus motor. The countersunk screws look like they are between 2-3mm thick.

It would be a great help if you can tell me the screw size, so that I can order some longer screws.

Thank you for your input.

Cheers

 

Edited October 17, 2021 by Prathab

[Prathab]

Surprised that I got no response. My C8 is probably older than 2006. The back of the scope is flat and focus knob cover plate was black (instead of the orange in newer models). The screw slots in the orange cover plate that came with focus motor matched perfectly. 

Took a screw to a few local stores with no luck identifying the size. So decided to throw money at the problem and ordered all the UNC sizes between 2&3mm in various lengths from accu. Screws arrived today.  The size that I needed was 4-40 at 1/2 inch length.

Installation went smooth and was able to calibrate it on first attempt. Was able to test focus on a distant tree. Hope it works ok on the stars.

Hope this helps anyone with a similar C8 model to install celestron focus motor. Image of the rear of the telescope to show the model I'm referring to.