Realizing that it’s essentially a cycloidal drive meshed with a planetary gear set, he got to work in ... To test this, [Michael] built a test jig with a NEMA 23 stepper providing the torque ...

In those mechanisms, a high-torque, low backlash gearbox might be just the thing, and a 3D printable split planetary harmonic drive for the popular NEMA 17 motors would be even better. Right up ...