Airsoft parametric bearing

This is a parametric version of the excellent bearing by Lamune
https://www.thingiverse.com/thing:1478868

I made it because I need a wider bearing, and I wanted to have control over the internal tolerances. It also opens up the possibilities of making bearings combined with gears and other fun mashups.

The diameters and tolerances are probably the only things you should really change.
But you might want to optimize clipBodyWidth so that it is exactly 2 filaments wide.

It is made to use the 6mm Airsoft balls (0.30 g)
I prefer the heavier ones based on the idea that they will be denser and more robust.

I had good results with clearance = 0.0 for PLA and 0.2 for nylon