Modulus Gear Customizer

Public Domain Modulus Gear OpenSCAD code
version 1.0
This code defines a gear based on its modulus rather than pitch in mm, Modulus is the ratio of tooth count:diameter, effectively the pitch of the gear is modulus * pi, ie, a gear of mod=1 has a tooth pitch of 3.1415mm.

The advantage of using modulus rather than pitch to define a gear is that it is very easy to prototype - for example, a gear of mod = 1 will have a diameter that matches the tooth count, with mod = 2, radius = tooth count.