[Mathew]

And remember, there is no Dual Angled Hinge Action, because the Clubface and the On Plane Clubshaft utilize the same Angled Hinge.

I knows Lynn knows this but want to further elaborate.

There is no dual angled hinge action when the vertical plane of the angled hinge action directly intersects the inclined plane which is the most common usage. However as angled hinge action is anywhere between horizontal and vertical hinge action on an infinite no. of planes and only one of them being directly vertical to the inclined plane the secondary hinge pin (1-L) has to be used.

The more that the hinge action veers towards horizontal from the inclined plane 'pure' angled hinge action, the more the secondary hinge pin will lift in the backstroke and lower on the downstroke and lift again in followthrough on the model of 1-L. Conversely for vertical - lower on backstroke, raise on downstroke and lower again in followthrough...