AT72ED Scope focuser support

This is a support to mount a stepper motor on a scope to be able to fine tune the focus using an arduino, and without touching the scope, avoiding vibration issues.
I'm using rubber bands to attach the mount on the scope, and a small belt to drive the focus knob.
I glued both parts after checking the position of the belt, knob and gear.
I used a gear from http://www.thingiverse.com/thing:16627 you should adapt to your belt.
I bought the belt from a hardware store, it's a spare for vacuum cleaner.