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

[Newton Hunt]

Ok, Richard, good reasoning but let's take it a little further.

By increasing the size of the knuckle (your numbers are good) the
capstan has to be turned down thereby taking it off the optimum line
between key balance point and wippen center pin.  This will increase
force required to depress the key.

You did not take the knuckle relocation far enough.  You know that we
have a simple lever and that changing the lift point toward the pivot
point will decrease the leverage and greatly increase touch weight
because a minor change of knuckle location is considerable amplified by
the leverage of the key.

Therefore the size of the knuckle is actually optimized to LESS than 10
mm, somewhere around 9.7 mm or there abouts.  This was determined by
mathematically determining what is the smallest number of teeth an
involute teeth a gear can have (13) and the optimum diameter of the
tooth radii, therefore it's diameter of about .3675" (if my memory
serves right).

That is why geometry is so critical to action performance and why so
much attention _must_ be paid to action part replacement selection.

                Newton