Servo-Motor-Mirror-Processor

You can click on the image to see a bigger version.

It may look medieval but it worked to process a 20 inch and a 16 inch mirror. Over 500,000 moves! OUCH LOL. I have the huge servo motor ( >100lbs ) / driver, ball screws and ball spline still. Don't know what you think about doing that sort of thing but I guess its secondary. However I sense you have a very organized approach to a build. The guy who handled mech on this project was a hack(understatement!) A friend and I wrote the VB app to pump data into an LM628 chip that sent the signal to the servo amp.

Media:MirrorMachineMovie.mpg
This movie includes a closeup shot of an automatic abrasives applicator. This applicator was originally a sex toy cut to fit strapped to the side of a tuna can. Later in the polishing phase an automatic liquid polishing compound applicator was made using a peanut butter jar and a cheap electric tire pump.