[sanddrag]

I think I might know what the involute surface is. Is it the front or rear of the tooth? In the firstcadlibrary model it is curved a bit. So this curve changes with tooth count? Is there some sort of formula to determine what radius this curve is based on the number of teeth in the gear? Also, I'm still clueless as to what the hobb is.

Thanks for your help everyone. I am learning a lot.