About this 3D model
Needed a simple gear that could be mounted with an external axel and driven by a central axel gear (sprocket). Didn't have the phone number for Spacely's Sprockets handy. Oh, to give credit where credit is due, the main gear is a variation of one of the gears found on thingiverse.com months ago. I apologize that I do not know of whom it specifically hails.