I modeled this on a surplus garage door opener gear set I used for a solar panel tracker system I built. http://www.youtube.com/watch?v=Xj-fqcNuqIk&context=C3a3cbd0ADOEgsToPDskKnJlu7Qa_3ZtIJa_xQ_wmG

I just wanted learn how to design worm gears in CAD. Even trickier than I imagined.

The worm has a 1/2" bore and holes for 0.125" Roll pins.

I think I am close but until I get my printer I won't know for sure.

This is a work in progess. I don't have my printer yet so I don't know if this works.