The file 'Bead Chain Gear For Stepper Motors With 5mm Shaft, E.g. For Polargraph Plotter 3D Printer Model' is (stl) file type, size is 102.5KB.
A remix of the bead gear found here http://www.thingiverse.com/thing:42188 - I only added a part ready to be put on a 5mm shaft of a standard stepper motor. The shaft can be fixed with a M3 screw from the side.
On my printer the 5mm hole was a bit too tight, a bit of work with a 5mm drill fixed this. The M3 makes its own thread when screwed in.
608zz_gear_mount.stl | 263.0KB |