Linear ball bearings

These are the designs for Mendel style linear ball bearings. The bearings are for use in a DIY CNC mill.

Since there isn't too much room for the bearings (especially at the Z axis), I designed the printed ball bearing retainers as low profile as possible. The "inner" ball bearings are halfway sunk in the base plate.
This not only keeps the assembly as low as possible, but also guarantees the same height reference for the fixed bearings (the axle sits directly on the plate). All upper bearings are adjustable.

See a video with a comparison of bush bearings and these linear ball bearings on the same rods:
http://www.youtube.com/watch?v=nL-CA5Fm8bk

For more information on the DIY CNC mill, see http://pleasantsoftware.com/developer/3d/2011/05/13/poor-mens-laser-cutter/