OpenSCAD Inverted Helical Gears

Remixed from the amazing Catarina's design (http://www.thingiverse.com/thing:1339) for use with my slew bearing (http://www.thingiverse.com/thing:885141).

It will work well with a driving gear made using Catarina's design with similar settings (height, tooth width and angle etc.) and can be modified for any purpose!