Open RPS20 pinion DXF in MoI, measure distances.

Roller diameter is 10 mm
Shaft radius is 25 mm diameter. (not needed)
Radius from center of shaft to center of roller is 30 mm.
Pitch Circle radius is 63.7/2 = 31.85. This is not quite the same as 30 mm.

So now the Curtate and Prolate radii can be calculated.
Will try for a new script for envelope later

Got to go to work now. Will look again tonight.

- Brian