Math/Physics Problem: degrees of rotation of tuning pin =howmuchpitch change

[Bernhard Stopper]

Bravo.
Bernhard Stopper

Richard Brekne schrieb:
> I was going to mention something along these lines but had decided to 
> not... but since you bring this in....
>
> It is of course interesting to delve into as much as you can.  I have 
> my own project going with explaining pitch changes due to string 
> deflections at the bridge and and with the help of PhD Alexander 
> Galembo arrived at a set of math formulas for calculating change in 
> pitch for change in length. This employs Hookes law and is a different 
> approach then using elongation formulas... which I have yet to see a 
> sensible explanation for in this context.  Regardless of approach... 
> one is immediately confronted with a host of friction moments and it 
> gets very iffy for more then very general querries right away.
>
> In the end... as related to the present issue... about all you can 
> model with maths here is how much increase in tension a free standing 
> string will experience for any given amount of movement for a pin of a 
> given diameter. Once you start adding termination and other friction 
> points as in a real piano you are not going to get much of anything 
> meaningful with math models... only hints of what <<should be>> under 
> uniform and ideal conditions... which of course never are in existence.
>
> In the end... a techs job is from a practical perspective a matter of 
> feeling, touch, listening... and putting these together to arrive at a 
> sensation of <<knowing>> what the string and pin are doing for 
> whatever kind of stress you are exerting on them. That takes 
> experience... lots of it.  The rest is academic... interesting... 
> perhaps useful.. perhaps as much a goose trail as anything else 
> depending on the tech pursuing the trail.
>
> Cheers
> RicB
>
>
>    Theory and Practice of Piano Tuning by Brian Capleton has a 40 page
>    chapter on Setting the Pin.
>    www.amarilli-books.co.uk
>
>    Ed Sutton
>
>