Touch Weight

[Isaac sur Noos]

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Vince,

I believe that you are also changing the moment of inertia with changes in
regulation parameters , attack angle of the keys, height of the centers -
while it does not make sense at first.

I concur to say that the leading of the keys is not the way the action can
be lightened, or make heavier, it is quite simple to experiment with leads
using double sided tape and normal cylindrical leads, you can experiment on
many kind of setups.

I believe that the action mass may match the pianists hand weight so to be
comfortable, finding the way to express those parameters in numbers should
certainly be useful.

Best Regards.

Isaac OLEG





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                        Isaac OLEG
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  -----Message d'origine-----
  De : caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]De la part de
madelyn mrykalo
  Envoye : dimanche 21 decembre 2003 03:10
  A : College and University Technicians
  Objet : Re: Touch Weight


  James Ellis <claviers@nxs.net> wrote:


    Touch weight and inertia are NOT the same thing at all. "Tough weight"
is
    merely a measure of static force. "Inertia" is a dynamic quantity.


    Neither is front weight the same thing as moment of inertia, which I
have already said.


    That's why putting more leads closer to the center of the keys
    will result in less "KEY" inertia. You will have to use more lead, but
the
    "key" inertia will be a little bit less. However, the keys are NOT where
    most of the total action inertia comes from. It comes from the hammer
    heads out on the ends of the shanks, because that's where the (mass x
    velocity squared) is concentrated.

    All I'm saying is that moving the leads closer to the centers of the
keys
    is not going to buy you very much, because that's not where most of the
    total action inertia is coming from in the first place.

    But then that is the only place we can change the moment of inertia,
unless we lighten the hammer.

    What it will do is
    weaken the keys, especially if you drill more holes, plug holes, etc.

    That's probably not going to be a problem.


    Those two things are about all it will do for you, other than just
making
    the keys heavier in the middle. So, before you haul off and re-do a
whole
    set of keys, drilling more holes, adding more leads, plugging holes, and
    moving all the leads closer to the center, remember: It won't buy you
very
    much towarding lowering the overall action inertia, because that's not
    where it's coming from, but it will definitely weaken the keys.

    If we are going to change the front weight anyway, because we are also
changing out hammers, the MOI might as well be dealt with then too.

    Merry Christmas, Jim Ellis


    _______________________________________________
    caut list info: https://www.moypiano.com/resources/#archives



  Vince Mrykalo
  University of Utah


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