---------- > From: Delwin D Fandrich <pianobuilders@olynet1.olynet.com> > To: pianotech@ptg.org > Subject: Re: Soundboards > Date: Saturday, August 16, 1997 9:39 AM > > Richard Moody wrote: > > > > To Delwin and List > > Some where along the line I heard that some makers used wedges > > between the sound board and rim ( in stratigic places) to help "shore > > up" the crown. Is this true? Or was I dreaming? > > Richard Dreamon > > > > ---------- > > > It's quite possible. A lot of things like this were tried that didn't > work. > > The only technique that I'm aware of that did at least partially work > was the arrangement developed by J. Bauer in which the soundboard was > mounted on a separate rim that was attached only to the plate. The outer > rim was a totally separate structure. Dear Del, Do I remember that Julius Bauer had a plate above and below the soundboard. I worked on at least one of these pianos years ago and recall that they would have been a very decent instument. James Grebe pianoman@inlink.com > > In this case we have to say that the inner rim was attached to the plate > and not the other way around. The plate was the main structural member. > An by itself, it was about as heavy as most pianos of the same size. > Anyway, it was fastened to the plate in a more-or-less conventional > manner by using closely spaced screws coming down through the plate, a > spacer mechanism—I’ve forgotten now whether dowels, spacer blocks or a > top liner was used—and into the inner rim. The plate was a > "full-parameter" plate in that the inner rim was mechanically fastened > to the plate all the way from the upper bass corner to the treble > corner. The “belly rail” was integral to the inner rim and was not > attached to either the outer rim or the keybed. The plate extended down > between the two rims and adjustment bolts were installed in the plate > the heads of which bore against the inner rim. These bolts could be > tightened against the inner rim and to some limited extent made the > crown to the soundboard assembly variable. > > The only reason that this scheme worked at all was because Bauer also > used what I would call a "half-rib" on each side of the soundboard. In > other words the rib was made of two pieces one on top of the soundboard > and one on the bottom. > > In “modern” piano construction nothing done to the parameter of the > soundboard is going to “shore up” soundboard crown—including the Mason & > Hamlin centripetal tension resonator. Crown is lost because wood fiber > crushes and creeps over time. No amount of strategically placed wedges > is going to change that. >
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