stretching wire -- an anecdotal analysis

[kurt baxter]

>
> Since when was Craig Brougher a "frustrated physicist"?!  He's just a
> vocal mender of player pianos.
>

My apologies. The way it read and where it was posted led me astray. Does
anyone know of any
professional scientists who have something to say on this?

(BESIDES the two references that were posted on the other thread that were
quite old, or a bit vague)


When plucked about 24 hours later a fall in the pitch of the note of 4 or 5
> cents was noted.
>
> 48 hours later the note is 9 or 10 cents flat.
>



This was the tuning pin to tuning pin in the piano leg, right?
The clear flaws I see that keep this experiment from saying
anything meaningful about string stretching is that the
factors of coil settling and wood crushing are completely
unmitigated.




There is approximately 400 cents worth of slack in the coil, after being
> brought up to pitch and pounded for a while.  I don't know if it should be
> called
> stretching for this slack to gradually unwind, but if the coil is not
> squeezed
> tightly, most of this slack will come out over the first year or two.
>



Granted, this sounds reasonable, but why should such tightening of the slack
in the coil happen slowly? What is the physical mechanism that causes this
type of pitch drop to be time release?




Kurt
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