Key Leads and Inertia

[Isaac OLEG]

I guess that what disturb the most the pianist is the initial breaking
of the inertia, once the key is moving he use the inertia and it's
kinetic energy.

That seems to correspond well to the more weight more centered idea,
but this in case of an action where the match between hammer weight
and action ratio is fair.

if the action ratio is too high, seems to me that the too large
inertia sensation at the beginning of the stroke remains whatever kind
of lead and placement is used, if more is employed near the balance,
it may help at certain key velocities, but the passivity of the system
certainly remains at others.

Are not too much lead dangerous for the flexibility of the key ? while
providing a "comfort element" as a predictable tactile sensation once
used to it, the few I've tried seem to push you towards the same
velocity range when playing.
At the same time some lack of response was perceived, but I have not
been able to understand where did it comes from.

Nowadays lead being a necessity, seems primordial to conceive the most
optimum match between the strings, soundboard system+ &  the hammers
to avoid unnecessary balancing .

B.T.W It should be fun to compare the acceleration of the piano hammer
with other extra fast objects, during the 45 mm it takes to hit the
string the speed the hammer attain is considerable, I'd like to say I
work on the faster accelerated object on earth for instance (and wear
protections while regulating let off).


Best Regards.

Isaac OLEG






Isaac OLEG

Entretien et reparation de pianos.

PianoTech
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> -----Message d'origine-----
> De : pianotech-bounces@ptg.org
> [mailto:pianotech-bounces@ptg.org]De la
> part de John Hartman
> Envoye : vendredi 25 avril 2003 15:30
> A : pmc333@earthlink.net; Pianotech
> Objet : Re: Key Leads and Inertia
>
>
> Paul McCloud wrote:
> > John:
> > 	I fail to see what this has to do with real-world dynamics.
> > Since the lead is integral with the keystick, not
> suspended by a thread,
> > the inertia is going to be the same no matter how much
> acceleration is
> > generated by the pianist's finger.  What am I missing?
> > 	Paul McCloud
> > 	San Diego
>
> Paul,
>
> I am just trying to visualize how a lead in a key
> would react to the acceleration of the key during
> play. A lead in a key assists the depression of
> the key at lower dynamic levels of play, ppp and
> pp. It does this because it has a negative
> acceleration - gravity - pulling on it.  Only
> after the lead is accelerated past the point of
> falling will its inertia be felt as a resistance
> to depressing the key.
>
> This means that if you install a lead in the key
> in order to lower the static down weight you
> assist the player if they are playing at a soft
> dynamic range (the action feels lighter). When the
> player increases the level of dynamics beyond
> pianissimo the lead begins to hinder playing (the
> action feels heavier).
>
> John Hartman RPT
>
> John Hartman Pianos
[link redacted at request of site owner - Jul 25, 2015]
> Rebuilding Steinway and Mason & Hamlin
> Grand Pianos Since 1979
>
> Piano Technicians Journal
> Journal Illustrator/Contributing Editor
[link redacted at request of site owner - Jul 25, 2015]
>
>
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