Re: Spur Gear DOP Measurement
DOP = dimension over pins (or dimension over wires).
Two wires are placed 180° apart in the gear teeth and a measurement is made over the wires. (On odd number of teeth gears, the wires are placed as close to 180° as possible.) Gives a relatively quick and easy meausrement of size and tooth thickness at pitch diameter. We use doble flank gear testers ourselves, but the supplier does not have this capability - thus we also measure the DOP.
I have seen and can cite *many* references to using two pins. I have not seen nor can find any references to using three pins, unless it is a worm gear or screw thread.
From the Machinery's Handbook:
Last edited by ScottyWM; 8th July 2008 at 12:45 PM.