Counter bearing treatment

[Newton Hunt]

Hello Ron, 

Sorry I cannot write that upside down so you will have to struggle
along with it wrong side up.

Thank you for your response to my post.  I like anyone that agrees
with me, weather I agree or not. :)

> However for many pianos, allowing the hammer shanks to travel past horizontal can marginally improve poor action geometry.

Hmmm, well, I can think of some pianos where this may have solved some
geometry problem or other by shortening the bore.  Hammers should
never be bored more than 1 mm or about 1/16" more than string height
minus hammer center pin height.  This can really cause regulation
problems.  Shortening the bore may help some specific problems but I
think I would really work at the regulation before I did so.  Of
course it is easier to shorten bore than relocate capstans so it some
situations this may be the more cost effective approach, but from a
geometrically correct approach I think it shortens the abilities of
the action.

> Many actions have excessive friction between the jack and knuckle,

Mathematically the correct dimension of a knuckle is 0.380" +/- .005
or so.  The size is dictated by the dimensions of an invalute gear
with 13 teeth.  Chris Robinson's son, a mathematician, worked this out
when Chris found so many different sizes of knuckles out there and
wanted to know the optimum size.

Shanks and knuckles are available with the proper dimensions and
locations.

> altered the wippen heel height on several S&S disasters to improve the geometry.

I have done this as well, but I am thinking that relocating the height
of the action is a better solution.  (How many technicians can cut
down a wippen heel?)  Instead of shortening a heel the same effect can
be had by raising the action and shortening the bore of the hammers. 
Provided there is sufficient room under the pinblock for the action to
move in and out.  Balance is.

> I find it incredible that a factory with such experience should choose to ignore a most basic action performance parameter - the key/hammer ratio.

All too often back shop practices are in disagreement with front
office desires and all too often changes occur without knowing
consequences.  If all were perfect we would be out of some types of
work.  Unfortunately the back shop ignorance matches outside practice
ignorance although I am hoping the later is moving faster than the
former.

I for one would like to know more about your new action and how it
differs from contemporary designs.  We here in the US have seen many
action designs come and go, some of those changes were good but not
picked up by the industry benches it is too slow to respond to
change.  Others went by the wayside because they did not stand the
test of time and experience.  I would like to understand how your
design improves performance, tone, projection, power, repetition and
ease of playing.

I look forward to your next post.

		Newton