Rigid Carriage for V-slot Kossel Delta

This is basically a stiff magball carriage for a Kossel V-slot delta printer, with 43 mm spacing, based on the Ultibots K250 / D300VS carriage.

For the 3W design view: http://a360.co/2yBcCaA
For the 4W design view: http://a360.co/2yvqQKd

I wanted to make it really stiff with a unbroken full frame, so I made wheel tensioning using a concentric spacer. I also designed a slot belt tensioning system where the tensioner is pushed through from behind, and endstop mounts that's mounted behind th