>This makes me wonder about the nature of castings; how long 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
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