Posted by Ron V on June 13, 2015 at 17:34:16:
In Reply to: Re: Checking Accuracy of Pressure Angles posted by BillS on June 08, 2015 at 13:03:16:
Well put Bill.
A simpler way of thinking/talking about it is by being more specific.
When it comes to pressure angles; there is the generating pressure angle and then there is the operating pressure angle.
Similarly with the PCD; there is the theoretical PCD and then there is the operating PCD.