Kossel linear bearing carriage for Trick Laser 3/8" barbells

When I found out about Trick Laser's nifty ball-cup Kossel arms with plastic barbells to guarantee arm spacing and reduce joint lash (see http://www.tricklaser.com/), I was immediately intrigued, but I couldn't find any designs anywhere for a carriage design using the barbells on a linear bearing with belts (as my Anycubic Linear Kossel XL uses) -- so I made my own. It has a built-in belt tensioning mechanism to boot, although the structure required to support it adds some weight it could do wi