Key Leads and Inertia

[Richard Brekne]

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The direct quote from the second link is

     "The well-known Steinway "accelerated action" works because it adds
     acceleration to the hammer motion by use of a rounded support under
     the center key bushing. This causes the pivot point to move forward
     with keydrop thus shortening the front side of the key and lengthening
     the back side and thereby causing the capstan to accelerate for a
     constant keydrop. This illustrates the importance piano designers
     place on accelerating the keydrop, and the arm weight method ensures
     that we take full advantage of gravitational acceleration to control
     the tone. The effectiveness of the "accelerated action" is
     controversial because there are excellent pianos without this feature.
     Obviously, it is more important for the pianist to control this
     acceleration."

Now this is a new one to me. And Phil Ford who just last week wrote such a nice
nearly error free essay on the reasoning for the accellerated action :)

The idea of a significantly changing key ratio tho.... is intriguing !

Thanks Cy

Cheers

RicB



Cy Shuster wrote:

> That's what Newton Hunt wrote in 1998 on this:
>
> https://www.moypiano.com/ptg/caut.php/1998-September/000822.html
>
> Here's another aspect of this fascinating dynamics discussion: the effect of
> the shape of the fulcrum under the key.  Dr. Chuang says that the rounded
> support under the key bushing (in S&S) moves the fulcrum towards the
> pianist's finger as the key moves downward, lengthening the back of the
> lever.  Is this effect significant?
>
> http://members.aol.com/Mccc8888/chapter1.htm
>
> --Cy Shuster--
> Rochester, MN
>
> ----- Original Message -----
> From: "Classic Touch Ent" <classictouchent@comcast.net>
> To: "Pianotech" <pianotech@ptg.org>
> Sent: Thursday, May 01, 2003 12:40 PM
> Subject: Re: Key Leads and Inertia
>
> > Hello again,
> >
> > I'm wondering if the concept of accelerated action has less to do with
> > the downstroke (less inertia to overcome on a high velocity strike)
> > than with the return (with the weight(s) closer to the balance pin they
> > are less effective counterbalancing the stack mass- potentially a
> > quicker return). I guess it has a perceived overall benefit on both
> > sides of the keystroke?
> >
> > Rich
>
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html


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