Capstans, Inertia

[Yardbird47@aol.com]

Thanks, Bill Spurlock, for your leading questions.
<<Have you had a chance to evaluate strike ratio of modern Yamaha and Kawai
actions, and how do they compare to your ideal of 5.5 of the Hamburg
Steinway?>>
The only non-Steinway piano I've surveyed was a Baldwin L. David I know has
done at least one Yamaha (a C7). I've always marveled that Steinway has to
hit and miss at putting a good action together, and Yamaha seems to hit it
every time. I've always assumed that it was a matter of locating the plate
front-to-back, and then trimming the under side of the rim at the arms to
control the string height. Regardless, I'd like to do a full survey just to
see what a Yamaha looks like
<<Next, I've wondered about the effect of wippen assist springs as used on
some Schwander and now Korean actions. Are there situations where the springs
(if quite strong) hurt repetition speed and reliability by working against
jack return?>>
All the springs do is to counter balance the weight of the hammers, just as
front leads do. I would love to find out more, but for as much as I know, the
critical motion for repetition is for the wippen to drop low enough for the
jack fly to leave the let-off button. Remember that the spring is strongest
in the rest position, and most of repetition's critical motion occurs at the
top of the wippen's swing, at the point of weakest spring pressure.
But there's more to fast and deep repetition than simply balance weight and
inertia. Ken Sloane has been working on it for years. It's not just a strong
rep spring.  And it's not just solid pinning at the hammer flange and rep
lever. Ken thinks that high checking is necessary, but one of the things that
the NH Chapter's Junior Science Project hopes to find out (among others) is
whether the tail and check ever do contact during the deep and fast, or for
that matter the jack button and spoon, and the front rail punching and the
key. I think repetition and inertia share common concerns, but at a certain
point begin to be solved separately.
David's system does one thing, to tune up mass and leverage (and believe me,
they can be badly out of tune). It does one thing and does it beautifully. As
LaRoy Edwards once said, "Nobody builds the perfect piano. We simply remove
the obstacles to a perfect piano." Sort of like a sculptor and his block of
marble