--On Tuesday, June 1, 2004 9:31 AM -0500 Mark Cramer <Cramer@BrandonU.CA> wrote: > if I may continue on the subject of drop for a moment, from experience, > does the drop setting vary with climate as let-off does? > > Or, are the visible disparities (between let-off and drop distance) > generally due to: > > 1.) initial setting error (as Fred demonstrates) > > 2.) the seasonal movement of let-off in relationship to a (typically > stable) drop setting. > > On lesser used instruments, I've allowed myself the lazy habit of setting > drop a little wide (confession is apparently good for the soul) so that > let-off settings could "float" to the wide side safely over summer. Hi Mark, I can't say from experience or observation whether or how much drop might vary with humidity. My educated guess is that drop per se would not vary enough to notice, but that where the hammer ended up after aftertouch might vary significantly (because of variance in aftertouch). Drop would be affected mostly by swelling/shrinking of the drop leather, and to a lesser (and, I think, negligible) degree by hammer felt and knuckle. Aftertouch is affected by a host of factors, including, most significantly, wipp cushion felt and keybed felt. I would be very interested to hear just what variance has been observed (for all regulation factors) in response to humidity change. What precisely changes and how much when the RH rises by 50%? Mark, you mention that you observe letoff is wider under higher humidity. I find that very interesting. The main factor that would lead to that is swelling of the regulation button felt. Other factors would mostly tend in the opposite direction. I'm thinking of swelling of: hammer felt; knuckle felt/leather; keybed; keyframe. Some might argue that rise of strings would increase letoff distance, but I doubt it. While strings no doubt rise at the bridge (swelling of the bridge and soundboard), this affect is reduced almost to nil at the strike point where letoff is measured, as the termination (plate/agraffes) doesn't move. Maybe I'm wrong, but it would be an easy thing to measure (taking it as string height relative to keybed). Has anyone done such measurements? Does anyone have hard data on variance of regulation measurements due to RH change? Regards, Fred Sturm University of New Mexico
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