Printable rack: Modular, parametric ,for rack&pinion system for Reprap

This is an OpenScad script to generate modular and parametric racks, for a printable rack & pinion system for Reprap 3d printers, as a replacement for belts or threaded rods.
More info here : http://www.kaosat.net/?p=1670
Please note that this is an experimental , work in progress version

Edit 07/01/11:
-Added the herringbone version , in wich you can set the center angle (see schematic), that script can also generate the straight teeth with an angle of 0
-this version is cleaned up and