NEMA-17 Planetary Gear Actuator

thingiverse

I plan to build a robot arm, inspired by LoboCNC's robotic arm: https://www.thingiverse.com/thing:3327968 I designed this actuator myself, although it heavily borrows its design from the one in the robot arm. This is a 2 stage compound planetary gearbox for NEMA-17 motors, intended for robotics. There are grooves cut into the ring gears where you have to insert 3mm stainless steel balls. They are available at bicycle repair shops or online stores that deliver. The bearings hold the two ring gears in place, but it's possible to pop the steel balls out due to the included clearances, requiring some elbow grease.