Summary

A parametric pulley designed to be clipped on a bearing.
It has flanges to keep the belt in.
It was initially designed to keep off my mendel X-axis belt from the fixed flange.

Instructions

Parameters are in millimeters except for Flange_Shape which is 1 if you want squared flanges or 2 if you want rounded flanges.
You may have to add a fraction of a millimeter to the Belt_Width to allow some clearance.

I have printed it without any noticeable problem. It fits tightly around the bearing and you'll need a hammer to mount it.

On a reprap, as the flanges make the pulley a bit larger than the bearing, you'll need to add a washer on each side.

Parametric Pulley