In the search for NEMA 23 mounts, I came up with a really simple design for the stepper motor mounts. I had two problems: The mount had to have wider than usual footprint as a regular one would bump right into the mounting bolts for the BK12 bearing block, and my milling/machining limitations prevented a more complex mount. I was a bit concerned about having it built into two separate parts. I wondered how it would handle axial forces. Once (my rather limited) mathematical models suggested plenty of rigidity, I built one to test. Indeed, these mounts don’t even notice the 400oz/in motors.