I tapped the mounting holes for 8-32 button head screws, and rounded the ends of the bearing mounts for a better fit. I wanted the ends of the mounts to be inside the square profile of the extrusion. I used 12mm bearings and shaft so the parts will be compatible with my Unimat DB200 machines. Now to make the pulleys.



I may thread one of this shaft for use as an auxiliary power tap. I also discovered that mounting one bearing 'inside-out' wasn't a good idea. There's no way to tighten or loosen the lock screws so the shaft can be moved.