Orca 0.3 Y axis belt tensioner

A replacement for the stock belt clap that includes a tensioning screw. This works in a similar way to http://www.thingiverse.com/thing:10274 but to maintain straight belt travel the belt is clamped at the bottom and free at the top.

The SCAD file is parametric so this should be adaptable to other machines and belt sizes.

**Version 2 makes the corners round, adds a slimmer clamping strap and incorporates Aggressive's impovement to the nipple form.