A reduction gear train made of pine plywood sheathing scraps laminated together with screws and powered by a 3/4 h.p. electric motor. Herringbone or Chevron gears are stronger than spur gears and do not have any tendency to move along the axle even under heavy loads. There are no bearings other than the center hole drilled through the plywood turning on half inch diameter smooth steel shafts lubricated with axle grease. The gear ratio is 72:1 not including the belt drive, the belt drive makes the overall ratio around 172:1 (About 10 rpm output with a 1720 rpm input from the motor). The gears are made using a technique I developed – visit my web site for more information.
This gear train was built for fun and to use up some small scraps of plywood laying around in my workshop. It demonstrates that wooden gears are capable of handling some load, but certainly not as much as metal gears. It is obviously an extremely dangerous machine and could easily crush hands, arms, etc…