Quick video, just milling a mounting bracket for the motor shaft. Rather than a grub screw, the d-shaft is sandwiched between two plates, and the whole thing screwed down to a 2x4 for testing. A cheap ...

Slide the two together, and the result is a far sturdier solution than trying to mate a 3D printed gear directly to a motor shaft with a friction fit or a screw. This solution isn’t necessarily ...