Ball Caster - Parametric

This is a small ball caster to be used on robots or other things that need to roll.

The openscad file is set up to easily tweak values for commonly changed parameters:

Ball Diameter
Airgap - How much play between the ball and the wall
Ball protrusion - How much the ball should stick out of the housing.
Total Height.
Base thickness.
Mounting screw radius.
Spread between the mounting screws.

I've started playing with a parameter to switch between two different mounting types. Thi