The file 'Belt Tensioner 3D Printer Model' is (scad,stl) file type, size is 1.4KB.
After seeing the Ultimaker Belt Tensioner by psync (http://www.thingiverse.com/thing:10034), I decided to model my own that didn't need a screw. But of course there's also Roboteer's Paperclip belt tensioner (http://www.thingiverse.com/thing:4535)
Note: It's been mentioned in the comments that there isn't enough space between the new style Ultimaker slider blocks and the belts. Which causes the tensioner to hit the blocks.
belt-tensioner.scad | 1.2KB | |
belt-tensioner.stl | 14.2KB |