Originally Posted by
TimM
Thanks for all the help! Perhaps this is the wrong forum or I am pushing my luck, but you have been so helpful that I'll ask a bit more. I've studied the gear() code and done a lot of Google search for terms. I learned a lot, but a few issues remain unresolved:
1) The usual definition of circular pitch is the distance along pitch circle from one tooth to the same point on the next tooth, with circular_pitch = pi / diametral_pitch, but the gear() code has circular_pitch = 180 / diametral_pitch which radically changes the meaning of this parameter.
Is there a reason for this apparent major departure from what appears to be standard practice? And in view of this, is the diametral pitch the usual 'Ratio of the number of teeth to the pitch diameter in inches' or is it also nonstandard?