>>What speaking length? > >And what strike point? Sorry, Ron. It's C5 (the note not the plastique), >and my notes are buried somewhere in a filing cabinet. I'll find them on SUN. Whatever. Meanwhile, I've made some assumptions. >In the meantime, I agree with you that movement of string across the >bridge has yet to be entered into the picture. Which seems to be inevitable, as relentlessly and near universally as even the possibility of it is ignored. >The string friction across the bridge due to downbearing has got to be on >the order of ounce, just like to test blow (or so I've believed). Right. Friction from downbearing is near nonexistent, or at least minimal, according to my calculations. >The tricker part is the friction due to side-draft. The unknown here is >what might be motivating the string to wedge itself into the corner at the >base of the angled bridge pin. Which I'd guess is several orders of mag >larger than the downbearing friction. It should be about like the friction from the capo. About 14 lbs per pin with a 10° side bearing offset angle. >It's actually possible, with a pocket microscope, to see wire move across >the bridge in tiny increments. Is it now? By who's observation? I have no doubt that it moves, but that's stretching credibility further than strings. >It might be possible to infer a friction barrier across the bridge top >(combining both aforementioned types of friction) by correlating a tension >drop (inferred from a itch drop as the tuning hammer pushes wire into the >speaking length) at the point where wire is seen to move across the bridge >(ie., the point at which the tension differential overcomes the friction >barrier). It's better observed in the other direction, where wire is pulled out of the speaking length, and a hard blow causes a drop in pitch. A blow induced tension spike in the speaking length won't have much affect if the speaking length tension is already lower then the back scale tension(s). The pitch drop has to come from somewhere, and you've already proven that the friction points between the tuning pin and the bridge have broken loose and moved because the pitch of the speaking length changed as the hammer was manipulated with a soft blow. That's the only control you get with the hammer. If a hard blow dropped the pitch afterward, the extra string likely comes from the other side of the bridge. >But then you really need to know whether the beginning tension on the >other side of the bridge to judge whether the tension differential started >out at zero, or whether it might have already been close to the size of >the friction barrier, either plus or minus. As I have repeatedly said. I wasn't sure that anyone had noticed. >To do that really accurately, you'd need a frequency counter, and a way of >activating the back duplex length so that this counter could successfully >read it. Maybe, existing tension could be accurately measured using a >sideways deflection test. And you'll do this on every string with every tuning? Would you like fries with that? And isn't that unknown tension differential across the bridge with every tuning you do the point? It was mine, anyway. >Hey, you brought it up. I think that gets you appointed to he committee. Pass. Committees make me itch. I'm just trying for at least a moderately realistic assessment of what we're all looking at every day. I know it's radical and likely doomed, but I continue to try. >BTW, you must be one them thar undecideds, I haven't seen you tossing any >termayders or goose eggs. >_______________________________________________ >pianotech list info: https://www.moypiano.com/resources/#archives Say what? If you're referring to the pointless and endless political drivel that's been flooding the list repeatedly all year, there must surely be more interesting things to think about. Ron N
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