Evidence of overlacquered hammers

Dean May deanmay@pianorebuilders.com
Sat, 2 Oct 2004 11:13:21 -0500


Bernhard wrote:
3. I always try to keep a gentle discussions niveau. To say that someone is
grossly underqualified, is not a good style.


My profuse apologies, Bernhard. I think there is a language barrier thing
going on. The grossly underqualified engineer I was speaking of was myself
in a self-deprecating style. It is why I refrained from jumping into this
fascinating discussion. I did jump in to talk a little about conservation of
energy, a subject that I used to know quite a bit about.

I have greatly appreciated your contributions to the discussion.


Dean
Dean May             cell 812.239.3359
PianoRebuilders.com   812.235.5272
Terre Haute IN  47802

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On Behalf
Of Bernhard Stopper
Sent: Saturday, October 02, 2004 9:15 AM
To: Pianotech
Subject: Re: Evidence of overlacquered hammers

Dean,
1. I am not engineer, I am a german master piano maker.
2. I did not exclude damping when i say:
>Not only. The function includes also the hammer speed and the strings
>impedance (including mass and tension of the string).

I spoke about the energy conservation on the whole chain from keyboard input
up to the soundboard.
If the energy input into the key remains the same, you have no gain in
energy in the soundboard if only the hammer is heavier.
If you change the hammers resilience, and therefore its damping, this is
another story.



regards,

Bernhard

----- Original Message -----
From: "Dean May" <deanmay@pianorebuilders.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Saturday, October 02, 2004 3:56 PM
Subject: RE: Evidence of overlacquered hammers


> Bernhard wrote:
> Yes thatīs what i say. As long as you put the same amount of energy into
the
> key, the sound will not be louder. This the principle of conservation of
> energy.
>
> Well, at one point engineers were invited to step into the debate but this
> engineer is grossly underqualified. I will, however, comment on the above
> remark. Conservation of energy says that the amount of energy after the
> impact has to equal the amount before the impact. Before the impact all we
> have is the kinetic energy of the hammer. After the impact we have the
work
> done in deflecting the string, the work done in compressing the hammer
felt,
> and some heat absorbed in the fibers of the hammer (some in the string,
> also). Changing the elasticity of the hammer will change the amount of
heat
> absorbed by the hammer and the amount of deflection of the felt. This
means
> either more (or less) energy must go into the string or into the returning
> hammer. So for a given energy imparted to the key, conservation of energy
> does allow for variance of energy to be transferred to the string by
> changing hammer densities, it seems to me.
>
> It has been fascinating to read both sides of the debate, except for the
> occasional forays into the ad hominems. Thanks to all who have
contributed.
>
> Blessings,
> Dean
> Dean May, PE             cell 812.239.3359
> PianoRebuilders.com   812.235.5272
> Terre Haute IN  47802
>
>
>
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives

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