Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4278695.

A simple 4:1 gearbox that I designed with a friend. Both the gears require support with shortest side down. Shafts are held in by the holding tabs, and are glued down. You can use the included fan blade as a waterwheel for fun. Please like, remix, make, and comment!