Keylead inertia and leverage (was Re: Ideal leading pattern:)

[Richard Moody]

----- Original Message -----
From: Mike and Jane Spalding <mjbkspal@execpc.com>
To: <pianotech@ptg.org>
Sent: Sunday, April 01, 2001 2:49 PM
Subject: Keylead inertia and leverage (was Re: Ideal leading pattern:)


>
> So, in both cases, the force AT THE WEIGHT is equal to 4*A.  But the
force
> felt by the pianist, AT THE FRONT RAIL, is reduced by the leverage:
For the
> weight at 4", the force is reduced by 4" divided by 8", so the
pianist feels
> 2*A.  For the weight at 2", the force is reduced by 2" divided by
8", so the
> pianist feels A.  Bottom line, the closer the weight can be placed
to the
> balance rail, the less inertial resistance the pianist will feel.
>
> Mike
>
    A key with 2 weights near the front rail can be made to require
the same down weight as a key with 4 weights near the balance rail.
The key with 4 weights is heaver than the key with two weights.  This
should make it feel harder to press it down (accelerate it) exp on a
ff  note.even though it still has the same down weight as the key with
only two weights.  The weight is the same to move each key, but isn't
more force is needed to accelerate the heavier key to the same speed
as the lighter key if both keys have  the same balance ratio?   ---ric