About this 3D model

Inspired by this http://www.thingiverse.com/thing:3981 and this http://www.thingiverse.com/thing:5584One of the first things I would like to print when I finish my Mendel is a roller bearing. I am also playing around with OpenSCAD so I have started writing a script to generated either complete printable bearings or just the races with an optional ball cage.The end result I would like is a lookup table of common bearing sizes, or size to suit.