The file 'Prusa I3 5mm/5mm Z-Axis Shaft Coupling 3D Printer Model' is (stl) file type, size is 13.0KB.
Customized version of http://www.thingiverse.com/thing:15633
Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=15633
This was customized to be a coupling between the 5mm z-axis steppers and 5mm threaded rod used on a Prusa i3. These seem to hold really well and are small enough to still allow the rods to rotate - other implementations were too large as the spacing between the threaded and smooth rods is narrow. These were customized to use US standard hardware:
customizable_shaft_coupling_20130623-1547-1ma22ao-0.stl | 199.3KB |