Mike, I didn't get this one in my "In" box, and only saw it because of Greg's post. >Michael Jorgensen wrote: > >> Ron, >> I'm confused. When the bridge/board expands/contracts thereby changing >> the string tension, do the strings stay in the same spot or do they slide >over >> the bridge? They slide. Soundboard rise raises tension more in the short backscale than in the segments in front (or above in a vertical) of the bridge. When the tension differences overcome the friction at the bridge (etc), the string renders through to more nearly equalize segment tensions. >If they slide, which way? If the kink slides toward the middle >> of the bridge, it would derail the string from the groove in the cap, hence >> appearing to "climb the pin." Sliding the kink further into the speaking >> length would also increase false beats. Could seating simply reposition the >> kink to its' desired location creating a straighter string and hence the >usual >> pitch drop? I don't think so. There's only a few thousandths of an inch of string length involved here. How much string do you take up on a tuning pin to raise the pitch ten cents? > Has anyone ever measured and documented exactly how much and >> which way(s) a bridge moves during weather changes relative to the plate and >> strings? >> -Mike How much depends on the friction points, the amount of soundboard rise, the string angle to the bridge, the string position on the bridge, and the proportional lengths of the string segments and which way depends on whether the soundboard is rising or falling, and whether the total length of string segments in front of the bridge is longer than those behind it. Ron N
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