plate reaction was Re: Pitch Raising to A440.......Or Not?

[sid blum]

>>...does the plate
> >continue to flex after a major pitch raise ?
> >
> >Sid Blum
>
> As far as I know, it doesn't enough to be a factor. The vast majority of
> plate deformation happens while you're changing the loading during a pitch
> adjustment. The long term changes will have more to do with string
> rendering and segment tension equalization and wood creep. Again - as near
> as I can tell. If the plate kept flexing and compressing after you were
> done messing up it's loading balance with the tuning process, a piano with
> as light a plate as an S&S D wouldn't be tunable at all, and that doesn't
> seem to be the case. Besides, if the plate kept deforming under tension
> enough to mess up a tuning some time after it was finished, wouldn't they
> all eventually pull themselves into a little ball? A plate adjusts to the
> tension changes as they happen - or breaks.
>
> I hear comments like "It's still drifting", after a tech has made a first
> pass and the piano is still 10 cents low. No, it's not still drifting, he
> just didn't overshoot the pitch enough.
>
>
> Ron N


After raising pitch 50-100 cents,and leaving the piano at 440 I usually
expect the piano to drop and need another tuning within a few weeks.  Does
this suggest that I am missing something?

Sid Blum
sid@sover.net