gearTemplate2.jpg
gearTemplate1.jpg
Woodworker Matt Wandel has a tool on his site for designing your own “low precision” gears (i.e. wood, phenolic plastic, etc) and printing them out onto paper templates for cutting. You can define two gears (with tooth size, count, angle) and watch them interact. The site also includes a brief tutorial on how to cut out the gears from the templates.

Interactive gear template generator – Link