Key Leads and Inertia

[Richard Moody]

> The leads that are closer to the center of the key will move
less >distance  and at a slower inch per second rate than leads
out at the >end.  Since the  inertial effect of mass  seems to be
exponentially >linked to speed,   keys so  leaded should
demonstrate less inertial >resistance to heavy playing than.

A good explanation of the so called "accelerated action", whose
concept of lead weights near the fulcrum has been vague to me at
least.

If Newton's law stands  "force is equal to mass times
acceleration" and if I am not mistaken in equating inertia with
force.  (inertia the force of a moving object) The more mass to be
moved needs more force.  The piano key in motion is most always a
problem of acceleration.  I always feel no matter how hard or soft
the blow I am always accelerating the key.   Does Steinway really
think that three weights near the center rail will offer less
inertia resistance (moving less distance) than one weight further
out?  In the  three lead case the mass is three times the mass of
the one lead further out.
    I am no physicist but I think they would say 3 leads close up
offers the same resistance or takes the same amount of force to
accelerated one lead further out.
    Balance is balance.  It is easy to see you can balance a key
with three leads close to the balance point or one closer to the
capstan.  If the balance is the same but one has more mass than
the other, does it require more force to move more mass?      Is
this line of thinking the reason why I almost flunked high school
physics?   ---rm




----- Original Message -----
From: <A440A@aol.com>
To: <pianotech@ptg.org>
Sent: Tuesday, April 29, 2003 5:33 PM
Subject: Re: Key Leads and Inertia


>
> The leads that are closer to the center of the key will move
less distance
> and at a slower inch per second rate than leads out at the end.
Since the
> inertial effect of mass  seems to be exponentially linked to
speed,   keys so
> leaded should demonstrate less inertial resistance to heavy
playing than
> those that is not.
>    I have found that leading the keys inboard like this,(part of
the original
> Steinway "Accelerated Patent) makes for a better feeling action.
I think
> this is because of less change in inertial resistance as the
force of the
> playing increases.
>
>
>
>
> Ed Foote RPT