BobDavis88@aol.com wrote: > John and others, > > I looked at your picture of the added top plates, and have a question. > Part of the stiffness comes from the taller beam and part from the > species. Would it do any good to rout out part of the top of the key and > replace it with a stiffer species, say maple, or would that be > insignificant if the key height remained the same? Same goes for shoes. > > Bob Davis Bob, Maybe you should do an experiment or model the problem? Crack open the old physics and engineering text books- the ones that smell funny - and sharpen your #2 pencils. This is a test. If you add 5mm of maple to the top of the key (25mm) it will be about (%?) stiffer. If you cut the key down and glue on a 5mm pieces of maple approximately how stiff will it be then? This shouldn't be too hard with beam flexure formulas and MOE - Just consult your PTG engineering hand book. A WAG (wild ass guess) supported, of course, by a solid theory will be good enough. My bet is on adding it to the top (or bottom). Any takers? John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor [link redacted at request of site owner - Jul 25, 2015]
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