Key Leads and Inertia

[Delwin D. Fandrich]

----- Original Message -----
From: "Sarah Fox" <sarah@gendernet.org>
To: <oleg-i@wanadoo.fr>; "Pianotech" <pianotech@ptg.org>
Sent: Monday, April 28, 2003 2:53 PM
Subject: Re: Key Leads and Inertia


> Hi all,
>
> Isaac wrote:
> > Nowadays lead being a necessity, seems primordial to conceive the most
> > optimum match between the strings, soundboard system+ &  the hammers
> > to avoid unnecessary balancing .
>
> Could springs not be employed instead of weights?  Lower inertia would
mean
> that more of the energy from the pianist's hand could be transferred into
> kinetic energy of the hammer, rather than dissipated in the form of heat
> when a more massive key bangs into the front rail punching.  Also, springs
> can move very quickly (faster than gravitational acceleration), so the
> system would be balanced and more responsive over a large dynamic range
> (therefore still assisting, rather than hindering, during ff passages).
> Piano actions are quite evolved, true, but it seems they have so far yet
to
> go.


Most of the energy lost between the key end and the hammer goes into bending
the key. At action saturation the front of the key fully bottoms before the
hammer starts to move. I'm not sure how much key leading contributes to this
but I shouldn't think it was all that much.

Del