The most important factor in any layout method is the pin to PAP distance.  That determines the percentage of the flare potential that is realized.  After that is chosen, the various methods simply define the exact pin position in relation to the gripping holes, the vertical axis line (VAL), and the midline.

The method I began using first is (pin to PAP distance) X (cg or mb to PAP distance) with the final pin placement specified by either the pin distance above the midline or the pin distance from the vertical axis line (also known as the pin buffer).  Example:  5 X 4, pin 3 1/2" above the midline.


Then along came the drill angle method, which uses the angle between the cg or mb to pin and the pin to PAP lines along with either pin height or pin buffer.

Then, most recently, the dual angle method which uses the drill angle and the angle between the pin to PAP line and the VAL to set the exact pin position.

All of these methods, and any others that may be invented, can set the exact same layout.  Choose the one that makes the most sense and is easiest to use for you.  A knowledgeable driller can select a layout that provides the desired reaction for a customer using any of them.  --  JohnP

Added on edit:  There is one more layout system I didn''t mention -- the clock system, which places the pin at a "clock" position from the cg.  Since it doesn''t use the PAP I don''t consider it a valid system.

Edited on 12/19/2009 7:07 PM