[deadsy]

I wrote a CAD package in Go that has a function for it.

https://github.com/deadsy/sdfx

  func InvoluteGear(
   numberTeeth int, // number of gear teeth
   gearModule float64, // pitch circle diameter / number of gear teeth
   pressureAngle float64, // gear pressure angle (radians)
   backlash float64, // backlash expressed as per-tooth distance at pitch circumference
   clearance float64, // additional root clearance
   ringWidth float64, // width of ring wall (from root circle)
   facets int, // number of facets for involute flank
  )