OpenSCAD User Manual/MCAD
number_of_teeth=15 number of teeth. Note that since circumference=2πr∝number_of_gears the distance_between_gears∝total_number_of_gears*pitch Basically if you have two gears, any two gears with the same sum number of teeth also fit at that distance.
circular_pitch=false, diametral_pitch=false proportional to the size of the teeth. (TODO proportionality constant)
clearance = 0.2
flat Makes the module a 2d object. This way you can `linear_extrude` it yourself.
The module has a lot of 'extra' features.
rim_thickness=8 Thickness of edges(where it contacts.
gear_thickness=5 Thickness inside, it cuts out a circle to make the inside flatter if smaller than rim thickness.
rim_width=5 How far from the edge the gear is made at the
hub_thickness=10,hub_diameter=15, thicker bit in the center.
bore_diameter=5 hole in center, for an axle, for instance.
circles=0 Makes the given number of holes around the center to save material
twist=0 Twist in linear extruding. Used for making helical gears. (e.g.chevron/herringbone or worm drive gears)
gear(number_of_teeth=20, circular_pitch=200, flat=true);