Your post re: Balance Weight

[Yardbird47@aol.com]

I was asked,
RE: <<I liken mass (or gravitational resistence) to the springiness of a
membrane. Let it slack and it moves with little pressure and has very little
pressure with which to return. Stretch it taut, and you know you're pressing
on a spring which presses back at you with equal firmness.>>

  <I'm not sure what you mean by the above sentences re:  mass and its
relationship to a membrane.  Gravitation is only attractive, so there is no
"springiness" in it.  What do you mean by letting a mass "slack" or "taut"
(the membrane I understand; the connection to the mass doesn't make sense to
me).>

Remember that the balance weight that you're feeling in the down and up
weights (with friction stripped out) is simply how much heavier the back side
of the key is than the front side. Press down on the key and you experience
the force required of your finger to move the key down and the hammer up.
Drop below that minimum force with your finger, and the key will push back up
on your finger with the up weight. If you raise the balance weight (by
removing front leads) the pressure of both the down and up weight will
increase by that amount. Drop the balance weight (by adding front leads) and
conversely both the down and up weights will feel weaker.
The finger might just as easily be pushing on a spring, whose strength is a
function of the balance weight (excepting that in this analogy, the nature of
a spring is that the further you displace it the stronger it gets, not so
with a piano key and lever train). Set 88 of these springs in a line and see
to it that although you may raise and lower the BW at your whim, the 88 BWs
form a straight line. This is when I imagine that what the fingers are
presented with is an elastic membrane, in which the the higher the BW the
stronger a force you encounter in both directions. Likewise with low BWs. Set
yourself a BW of 25g, and with a friction running evenly from 15g at note #1
to 10g at #88, and with the down weights running from 40 to 35g, you can play
this action with the bat of an eyelash. A butterfly could play it. But with
up weights of 10 to 15g your fingers may frequently find themselves losing
contact with the keys as they return faster than the keys.
This is the analogy I give to pianists.

Bill Ballard RPT
NH Chapter, PTG

"There are fifty ways to screw up on this job. If you can think of twenty of
them, you're a genius......and you aint no genius"
Mickey Rourke to William Hurt, in "Body Heat", discussing arson.