This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment ----- Original Message -----=20 From: Erwinspiano@aol.com=20 To: pianotech@ptg.org=20 Sent: October 17, 2003 9:13 PM Subject: Re: Private post/Steinway Tone Bell The bell is just a plate stiffening device. A short beam from the = belly rail to the case in the same area would allow for another nose = bolt that could take the place of the bell. I cant say the bell has any = effect in and of itself to influence tone but does stiffen the plate web = where it attaches thereby influencing tone. There must be a modest down = force of the bell bolt to do so which by the way will increase the = downbearing a small amount (tone effect) These bolts also seem to come = loose from time to time and cause a weird rattle. Take the coupling bolt out of a D sometime and listen to what happens to = sustain through that area. Does that help?--Dale This reference to the "bell" brings to mind a question I have = long had. S&S piano plates are sometimes billed as cupola plates. Does = this refer to the shape of the stress holes in the plate, or to = Steinway's use of a shop cupola furnace to produce sufficient amounts of = molten iron for the larger plate ?=20 Glenn I don't know. Anybody else? I thought that term was used in = reference to the bass bridges on S&S uprights or have I got it ALL = wrong? Dale It is a reference to the shape of the plate in cross-section. Among = other meanings this is an architectural term meaning a "dome-shaped = roof" or a "dome on the roof." The hitchpin panel and the outer bolt = flange are in one plane and the section between "domes" up in the shape = of a cupola. The idea was to stiffen the plate and help keep it from = twisting. I suspect it was introduced as part of the transition from = earlier flat-strung scaling (with its more-or-less parallel lines of = stress) to overstrung scaling which introduced quite a lot of torsional, = or twisting, stress. Considering some of the iron being poured at the = time -- some with tensile strengths as low as 12,000 to 15,000 lbs/in2 = -- it is understandable why they might have considered many ways to = increase the stiffness of the plate.. Del ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/06/43/25/03/attachment.htm ---------------------- multipart/alternative attachment--
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