On 4/18/07 1:31 PM, "Ron Nossaman" <rnossaman at cox.net> wrote:
>as Ron just said the string render at random times. Maybe
> a year or two or three later.
> Not that much later, I think. Weeks, maybe, but likely not
> years. It has occurred to me though, that some of that initial
> pitch drop we attribute to strings stretching could very well
> be coming from the back scale. I'm still of the opinion that
> most of the pitch drop we see in new pianos and rebuilds the
> first year is from the cap crushing at the notch edge, perhaps
> some from pinblock compression at the flange, and very little
> of it from string stretching.
My own take is that most of the pitch drop comes from the string conforming
to the angles it is forced to go around. Creating positive bends (pressing
against the string with a sliding motion) at each of those points hastens
pitch stability considerably, in my experience. Most new pianos don't get
that treatment, and so you find that high treble notes will go 100 cents
flat through vigorous pounding. Part of that is back scale coming through,
part is making those duplex/bridge pin/capo/aliquot bends more positive
during the pounding process, IMO. But you are probably right, Ron, in saying
that part of it is also crushing of wood.
From an earlier post, yes, I understand string does render across the
bridge form time to time. It just doesn't saw back and forth during the
tuning process, like at the capo. Hence, far less chance of "wearing out"
from friction. If wire is going to wear out from friction, it'll happen at
the capo. I don't think it does there either, though I could be wrong. I
think breakage there is from work hardening due to repeated flexing. The
friction arguments for why hardened terminations would cause string breakage
don't ring true to me. Strings don't break at the capo while tuning. They
break there during a hard blow.
Regards,
Fred Sturm
University of New Mexico
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