This pulley was designed to press fit onto Sparkfun.com's stepper motor (#ROB-09238). It was used to create SADbot, a project featured in my book Making Things Move (www.makingthingsmove.com) that Ben Leduc-Mills and I created for the window gallery at Eyebeam Art + Technology Center.

When printed on Eyebeam's Dimension 3D printer, the pulley is a tight hand press fit to the shaft.