This project introduces 3d printed planetary gear actuator. The planetary gear actuator is equipped with a VESC firmware-based motor controller, and the motor controller hardware has also been developed in my other project (https://hackaday.io/project/167660-mj-vesc-circular-type-ver-03). The planet gears have the gear rate of 8:1 and the external diameter is 56mm. The motor used is a Tarot 4008 (330 kv) motor. The 1-stage 8:1 gear rate enables fast motion, good back-drivability and very little gear backlash. The gear design was done by 'Design Accelerator' in Autodesk Inventor. The gears has 14.5deg pressure angle and 25deg Helix angle. The ring gear has 70 teeth, planet gear has 30 teeth, and the sun gear has 10 teeth with gear module 0.65mm. The entire actuator module design file is 'mt4008_Act_Ver8.iam'.
The fully 3d printed 8:1 planetary geared actuator is controlled by mj-vesc(https://hackaday.io/project/167706-mj...). The precise position servo control is done by goto control mode(https://hackaday.io/project/167706-mj...). In this video, it shows the repeatability of single actuator. The result shows that it guarantees sub 0.01mm accuracy (standard deviation : 0.0058mm measured at 150mm from actuator center)