><< On that S&S D I posted tension figures on, it made 18 lb difference between > 435 and 440. In a piano less heavily loaded with bearing than this one was > in the treble (2.4°), it would be less. Maybe it would be better to let > this one go, I don't think it would impress them all that much. <G> > > Ron N > >> > >If a 5 cent increase in tension resulted in 18 lb. of addition down bearing, >would a 50 cent increase be 10 times that much, or 180 lb.? And would a 100 >cent increase result in a 360 lb. increase? If so, is that impressive enough >for a customer? Since they have nothing to compare that to, maybe it >wouldn't. What do you think? > >Willem Hi Wim, Not a 5 cent increase, a five cps increase = 20 cents increase = 18 lbs. That's 0.9 lbs per cent. My spread sheet shows a semitone increase from A-4 = 415cps@704 lbs to A-4=440cps @792 lb. This isn't exactly accurate though, because there's no allowance for the fact the bearing angle decreases as the board is loaded, so the bearing actually increases in a diminishing progression with tension, rather than in a linear fashion. I considered trying to build it in, but it got too complicated for the importance of the information obtained, so I didn't attempt it. So with a roughly 18 lb bearing increase with 20 cents pitch increase, you'd be looking at probably under 75 lbs bearing increase with a full semitone pitch raise to 440. The tension increase is still lots scarier. Ron N
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