Parametric Timing Pulley v3

NOTE: "These are not the timing pulleys you want". No really, you want version 4, which is here:
http://www.thingiverse.com/thing:36568

This is an OpenSCAD parametric model for making most any timing pulley that you need. It's designed to generate a model printable without support material (observing the overhang rule of thumb).

You can configure it to fit the belt that you're using. The pulley can be fixed to a threaded shaft with a nut. On one side the nut (the setting for an M8 hex nut is configured for you already) will sink into the pulley. If you tighten a nut on the other side as well it will be very well fixed.

Another option is to use set screws. You just specify the diameter of the screw and it will create a hub with a (capped) teardrop hole. The set screw option has been fixed in this version so that odd numbers of set screws (such as the very useful 3 set screw version) can be supported without the holes going out the back of the hub. An option has also been adde