Gears fablabchemnitz.de.gears 24 1.0 mm cm in pt px Module Circular Pitch Diametral Pitch 20.0 false false false 0 0 false 4.0 3 3.0 10.0 automatic 20 points: best 12 points: medium 6 points: low Use higher accuracy with lower tooth count. Set Number of spokes to 0 to disable. Set Mount hole diameter to 0 to disable. false 10 5 5 The matching rack gear is drawn additionally and below the spur gear. Gears: Be sure to set the document properties to inches or mm if you want real-world dimensions. For gears to mesh - the size of the teeth on each gear must be the same. This is why tooth count and Circular Pitch or Metric Module is used to define gears and not radius. The Circular Pitch, p, is the distance between adjacent teeth around the Pitch Circle. p = pi * D / z - where z is the number of teeth on a gear of pitch diameter D. The SI measure is the Module - which expresses the core ratio of Pitch Diameter to number of Teeth: m = p / pi = D / z where: - Pitch Circle: Radius is equal to the distance from the center of the gear to the pitch point. - Pitch Point: The point of tangency of the pitch circles of two meshing gears. Gears: Pressure angle [in degrees]. Usually 20. Historical: 14.5; High torque gears: 25. The higher the pressure angle, the stronger the teeth. With higher pressure angles, more effort is needed to turn the gears (due to friction). Caution: Undercut is currently not generated. E.g. a gear at pressure angle 20 deg and less than 17 teeth would either need a (negative!) profile shifting or will cause undercut. We only produce a warning. true all