Parametric Herringbone Gear Set for Stepper Extruders

This is an OpenSCAD script for the generation of a stepper motor gear set, to your exacting specifications.

I'm sure there's other scripts like this out there, so here's what makes mine cooler than theirs:

• I made it!
• It's ANIMATED! Yes, OpenSCAD has an animation option, and this set will take advantage of it. It seems like Thingiverse may not render a GIF though, so here's a link to a copy: http://scribblej.com/wadesgears.gif (obviously, that's animated through 1 gear length so it's only 5 frames).
• I made it!
• The perfect companion to: Parametric Tensioner: http://www.thingiverse.com/thing:6492
• I made that, too!
• Goes great with: Stepper Motor Mount http://www.thingiverse.com/thing:6549
• I made it!

... that's about all I got, really. Based loosely on TheRuttmeister's excellent herringbone gear set here: http://www.thingiverse.com/thing:5795

THANKS to the entire crowd on IRC Freenode in #reprap, #makerbot, and #makergearv2.

SPECIAL THANKS to GregFrost for his involute gears script and some special handholding while I was writing this.