GEARS! (Metric)

thingiverse

Check out my Imperial set of gears here for gears with a convenient tooth size for things designed in inches. This is a set of mating gears with a diametral pitch (P) of 1tooth/mm. I include gears for 10-40teeth in increments of 2 teeth. For gears in this set, center distance is simply half the number of total teeth between 2 gears, in mm. I explain this calculation below. These are true gear profiles designed using engineering grade software with a common 20 degree pressure angle. Will make similar sets for other common profiles like 14.5 degree pressure angle as well as an imperial gear set with a diametral pitch of 20 teeth per inch. As well, I include the inventor part files in case anyone wants to use inventor to modify these (even though they could just use inventor to easily create these gears themselves). To obtain the center distance between 2 gears you use the pitch diameter (D) of each gear. The formula for pitch diameter is D=N/P where N is number of teeth. The center distance is then (D1+D2)/2. This is because the pitch diameter represents the diameter of an imaginary cylinder whose surface would touch the surface of the imaginary cylinder representing an opposing gear, so the center distance is the sum of the radii (half of D) of the 2 mating gears.