S & S 'A' parts, geometry -- shanks and flanges

[Newton Hunt]

I've taken readings from .357 to .395 in the same set!!!  Does it not
also effect the relationship from whippen centerpin to hammer flange
centerpin?...Where's that knuckle supposed to be at rest?

Good question, Dave.  If I remember my theory right, the knuckle lies
along a straight line from hammer to wippen centerpins at the beginning
of let-off.

Go check an action and let me know.

        Newton