Parametric Peristaltic Pump

This is a peristaltic pump design adapted from emmett's [Planetary Gear Bearing](http://www.thingiverse.com/thing:53451). It prints as a single piece, with captive rollers and no rotary wear surfaces. The only non-printed part is the tubing itself.
This is a proof-of-concept and can be driven (out of the box) with a standard nut driver bit. For real applications, you probably want to add a mounting feature for a small electric motor or similar. The pre-baked STL file is for typical 3/16 inch OD latex surgical tubing; for other tubing or to adjust other parameters, use the OpenSCAD file and customize as needed.