Here I present a design for a compact lego technic 2 speed automatic gearbox. Instead of using a differential to react to torque on the output it uses the force on the gear teeth to push a liftarm to automatically change the gearing ratio to the 2nd speed once the torque threshold has been exceeded. The automatic gearbox will switch back down to the first speed once the torque on the output is reduced by using two rubber bands to pull back the liftarm.

The first speed is simply a 1 to one ratio and the second speed is a 0.6 ratio. The design can be easily modified to change the the second gear speed to other ratios such as 0.36 or 0.2.

SUBSCRIBE HERE: https://tinyurl.com/s2frxnf

Build instructions: https://rebrickable.com/mocs/MOC-4979...

#technicbrickpower, #legotechnic