Bill, a fellow named Carl Wicksell (now deceased) made a "tensionometer" which demonstrated pretty well what goes on between the top and bottom of a tuning pin. You can see it in the Sept 1976 Journal on page 10. Ted Simmons, Merritt Island, FL >On Tue, 3 Sep 1996, Bill Ballard wrote: > >> Hey Gang, >> Guess what I did last Sat. I took a piece of pinblock scrap and made a >> device for observing tuning pin torsion (you know, the twist which we >> leave in a tuning pin if we're not careful). Drilled a hole for the >> tuning pin, ran a band-saw kerf over to it, and set a lag bolt across >> that kerf for adjustable torque on the tuning pin, installed a piece of >> music wire leaving the bottom end of the pin which could be visually >> checked against a piece of wire coming out of the becket. At rest, the >> two wires were set parallel. >> >> The results were dumbfounding (actually, it doesn't take much). Even at >> 200 "/# torque (the most I could get from this firstversion of the >> torsion indicator), there was nary a 1 degree lag between the top and >> bottom ends of the pin. and as soon as the bottom stopped moving, and I >> stopped pushing on the top end, the two were in perfect alignment. So >> where's this mythical "twist-in-the-pin" which haunts our dreams? It >> probably has as much effect on the stability of the tuning as the test >> blow, which (as calculated for the string path of C52 on a Steinway B) >> barely musters 3.7 oz.(correct me if I'm wrong, Doug - you've got the >> spreadsheet) of extra string tension in the face of the 20# >> friction barrier presented by the capo bar. (BTW, this is part of the NH >> Chapter's Jr. Science Project.) >> >> Startled? Check it out for yourself....... >> >> Bill Ballard RPT >> NH Chapter >> >> "We mustn't underestimate our power of teamwork." Bob Davis >>
This PTG archive page provided courtesy of Moy Piano Service, LLC