This is a spreadsheet that will generate a list of points for half a gear tooth (image shows CAD result for 3 teeth) depending on the number of teeth, pressure angle and profile offset. From there you can load it into your CAD software of choice.

I've based this off of the equations and methodology from the following: http://school.mech.uwa.edu.au/~dwright/DANotes/gears/appendices.pdf (Appendix B) and: http://school.mech.uwa.edu.au/~dwright/DANotes/gears/generation/generation.html#top

I've given up on trying to code this in any way.

Watch this space for instructions.