Steingraeber factory pictures, bridge agraffes & adjustable vertical hitchpins

[Stéphane Collin]

Isn't it so that these agraffes favor the vertical plane oscillation of the 
strings, keeping the force vectors acting from string to bridge (and 
soundboard) and other way round in the direction that makes the transfer of 
the acoustic wave the most efficient ?  So, in a way, the driving force, 
being something close to average vertical to the board it is driving, will 
drive it better, which will have the same effect as if the board was more 
free, no ?

I would expect that the designer adapting such agraffes on a traditional 
piano would have to tweak the impedance matching between strings and board 
assembly, I mean not only because of the extra mass of the agraffes on the 
bridge, but also because of that more efficient transfer of the wave.

Best regards.

Stéphane Collin.

----- Original Message ----- 
From: "Ron Nossaman" <rnossaman at cox.net>
To: "Pianotech List" <pianotech at ptg.org>
Sent: Wednesday, May 03, 2006 5:48 AM
Subject: [Norton AntiSpam] Re: Steingraeber factory pictures, bridge 
agraffes & adjustable vertical hitchpins


>
>> Yes, the string bearing is reversed, but the concept behind is that you 
>> don't have tension sideways on the bridge, which helps the soundboard 
>> vibrate more freely.
>>
>> Yoshi
>
>
> And how does that work? In my world, the soundboard isn't changed by the 
> string termination at the bridge, and will vibrate pretty much the same 
> with either system. The real difference is in the mass on the bridge 
> which, if anything, will impede the vibrational freedom (amplitude, in 
> this case) of the soundboard assembly by lowering it's resonant frequency, 
> increasing it's mechanical impedance, and extending sustain.
> Ron N
>
>