(Please note: I have not tested this code yet.)
Arduino code to drive 3D printed ABENICS active ball joint mechanism. Requires 4 stepper motors.
3D printed ABENICS active ball joint mechanism: https://www.printables.com/en/model/482299-abenics-mechanism
Gears to attach on your stepper motors are at: https://www.printables.com/model/853586-abenics-driver-screw-gear-and-mounting-plate
The original ABENICS mechanism was introduced in:
Abe, K., Tadakuma, K., & Tadakuma, R. (2021). ABENICS: Active ball joint mechanism with three-DoF based on spherical gear meshings. IEEE Transactions on Robotics, 37(5), 1806-1825.