[Tristan Lall]

For most purposes, I find it easier to simply use cylinders in place of actual involute teeth--it's just too difficult to model an accurate involute. (Not impossible, just messy and difficult!)

If it's for display, the teeth may look nice, but it's actually easier to just work with a cylinder with the diameter equal to the gear's pitch diameter. There's less work for the computer to do (rendering and evaluating all those faces), and it's easier for the designer to select and manipulate the part.

Like this....
(Note: that's an improved version of the Woburn Robotics 2004 gearbox....)