----- Original Message ----- From: "Ron Nossaman" <RNossaman@cox.net> To: "Pianotech" <pianotech@ptg.org> Sent: Friday, April 11, 2003 7:15 AM Subject: Re: Killer Octave Question > > >Del or you or someone also wrote a while back some examples of how much a > >rim might commonly move by every-day events - like someone leaning against > >it, or the size change caused by a humidity change. As I recall these > >movements easily were greater than the change in rib length between curved > >and straight. Any recollection of this? > > Yes, but not the numbers. Anyone who's interested can take some > measurements of their own in a piano they have the soundboard out of and > see what kind of pressure it takes to deform a rim 0.008", or a belly rail > 0.0004". Actually, my Journal article "A Guide to Soundboard Cracks & Other Maladies--Part I" (The Piano Technician's Journal, December 1997) had both a drawing and numbers. I might add that you are being very generous with your numbers. I doubt many compression-crowned soundboards have anywhere close to a 40' radius on intallation. Del
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