Contraptor - shaft mount

This thing is a part of Contraptor - a DIY open source construction set for building Cartesian robots: http://contraptor.org

A pair of shaft mounts with bearings support a threaded rod used as a pulley shaft or a lead screw.

Sketchup source:
http://sketchup.google.com/3dwarehouse/search?q=contraptor+shaft-mount