I found a neat little tool the other day that I thought you folks my be interested in. It's called Gear Generator: http://www.woodgears.ca/gear/index.html

The software is $23 and will create DXF files suitable for cutting gears on your ShopBot.

The main woodgears.ca site showcases some of the projects the guy has built. He'd be an animal if he had a 'bot! *laughs*

g.