NEMA17 Stepper motor spacer

Since I'm replacing the Z axis in my Replicator clone with a threaded rod that's 3cm too long, I needed to lower the NEMA 17 stepper motor bolted to the bottom of the printer. This is a spacer to accomplish just that. Adds about 3.5cm of spacing (it turns out to be exactly the height of a typical stepper motor). Changing the length to what you need should be easy enough in blender :)

EDIT: I forgot to account for the size of the coupling I'm using. I've added a version with a circular cutout