George F Emerson wrote: > Well, Ron, I've mulled it over all day, and I have concluded that you > are right and I am wrong ....probably. Frank, I keep trying to make the point that I don't care who is right. The important thing is *what* is right, rather than who, right? > Ron N replied: >> I suspect so too, if you're careful. Now, what happens when >> the impulse pulse of the hammer strike hits the termination? >> I'd bet the string will go back down to a negative bearing >> position. > > Negative bearing? Why not zero-bearing? In fact, that is what > convinced me that you were probably right.... the presumption that a > string under tension will do its best to find zero bearing, within the > constrains of the system, and that any vibration of the string would > only encourage it to do so. Because the clamping action of the slanted pins and offset angle represents a downward force vector. That's what the slant and offset are for - a clamp. Since you started with a negative bearing before lifting the strings up the pins, you'll get a negative bearing as the string stabilizes on the pins in play. If the original negative bearing wasn't extreme, the string might well go back in contact with the bridge cap. > The problem is that this line of thinking is based on a presumption. > Your photo only proven that this particular piano has negative front > bearing, that the string would likely seek and find a point closer to > zero-bearing, and that the friction with the bridge pin would help to > keep it there. No, it doesn't necessarily have a negative front bearing. There are many pianos out there just like this with positive front, rear, and overall bearing. When you tap the string, you see it move. The notch edge is crushed far past what bearing angles could produce. So bearing has very little if anything to do with this. >In another sense, the problem is that we have > unquantified (or poorly quantified) competing forces of static friction, > dynamic string vibration, substantially greater side bearing than down > bearing .... a recipe for potentially surprising results. That looks a lot like an ink cloud. > I must qualify my surrender with "probably," because I have often been > force to give up my presumptions in the light of myth-busting studies, > experiments, and slo-mo photography. Much as I would like to pursue > this further, I still have bigger fish to fry. > >> And no, you can't prove a negative - or anything at all to >> anyone who already knows different. But I try. > > Relax, Ron. You win! No, I didn't. I lost because you ducked without understanding. Another time, perhaps. Ron N
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