At 4:49 PM -0800 10/31/02, David Love wrote:
>That seems all very well reasoned. Does that suggest, though, that the
>dilemma can't be resolved by simply going to a higher ratio to yield a
>greater sense of control, coupled with an assist spring to allow for a
>little more mass in the hammer which also serves to maintain coupling?
If one wanted a piano on whose action one could explore the benefits
only available by high ratios, that's what one would have to do. I
did mention that if during the transfer of load-balancing
responsibility from the FWs to the springs, the BW stayed the same,
that I guessed that the coupling would be identical before and after.
(Naive little me, right?) So that would be all you'd have to do to in
changing over to a high ratio action to leave the coupling
unaffected, just keep the BW constant.
>Or will the increased inertia as a consequence of the higher ratio and more
>hammer mass not be adequately compensated for by the 9 or 10 grams of FW
>removed by virtue of employing the assist spring.
If 10g is your ceiling in terms of how much of the balancing work you
want the spring to do, then depending on how the action ratio and the
SWs combined, a spring only balancing 10g's might not be sufficient
to disguise the fact that this action is the combination of high SWs
AND action ratio.
>The general belief has
>been that higher ratios must be combined with lower strike weights and vice
>versa for that action to feel "normal". To what extent will the assist
>spring "normalize" the feel in the case of high ratios combined with high
>strike weights?
Good question. We need pianists to answer that one.
>Is this where we need the dynamic model!?
A few years back, Stephen Birkett was looking for a PTG Foundation
grant to construct a dynamic model. I thought it would have been a
real good deal: what a tool for analysis, for exploration.
BTW, I'd like both you and RicB to understand that I'm not in favor
of stretching the action hanging in this manner. I merely described
what I though might be the special advantages of a high ratio action,
which was the final point in your previous post. The more SW you have
to give up because of that ratio, the more those advantages disappear.
I actually think that however the action may have delivered to hammer
to the sting (and how it may have resisted the pianist's work to do
that), once the hammer hits the string ,it's a whole new ballgame.
The rules here have nothing to do with how well matched the the
hammers and the action may be to each other or to the pianist. What
is important at the point of impact it just how well match the
impedance of the string is in absorbing the force of the hammer'
blow. Here is where the SW has a completely different effect.
Bill Ballard RPT
NH Chapter, P.T.G.
Reality is the first casualty of technology
...........NPR Commentator Daniel Schorr
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