Hub width problems - need to find something skinnier!

You’re welcome! The suggestion of John is another good one. I just spoke Tommy Miller for 1 hour! I only met him once, but he did remember me (or at least; one of my unicycles).

I even used 3D printing to test my CNC code to create ISIS:

If the material and printer are good (and the conditions of the room where you do the printing), then you end up with very precise pieces.