Remix of Eric Lien's Eustathios v2 Spyder belt tensioner. This version is designed to work with 10mm cross bars, 30mm graphite bushings (still uses a 15.9mm diameter opening), and allows the cross rods to be removed without a full disassembly of the x-y gantry. (update: it turns out that the cross bars can be removed from the original belt tensioners by sliding the bar to one side and lifting it out)
A version for 8mm cross bars is included, but it has not been printed or tested.
This version needs support material to print (the original does not). I would recommend using the original parts, they've been tested on a lot of machines. Once you have a working machine, it's easier to customize it further.
Filaments: (full list can be found on thrinter.com)
-- Hatchbox Transparent Black ABS
-- Hatchbox Transparent Red ABS
-- 3D Solutech See Through Orange ABS