At 07:52 PM 11/16/95 -0700, you wrote: >To Jim Harvey - > >I understand you are describing and questioning the direction the string jogs >when crossing the bridge. And, of course the direction of the jog must be in >the same direction as the downward slant of the bridge pins. > >I think I was not clear enough in my earlier post where I recommended >slanting the bridge pins downward toward the middle of the bridge. Let me >try again. > >Assume we're dealing with a three-string unison in the mid-range of a >medium-sized grand, and we're inventing the bridge from scratch. In >conventional practice, we would drill for the front row of bridge pins by >drilling down and to the right (leaning the top of the drill to the left); in >this case, the strings would deflect to the right as they cross to the rear >row of bridge pins, then turn left as they continue on to the hitch pins. > (The rear row of bridge pins would lean in the opposite direction of the >front row, per usual.) In the ideal scenario, all three front bridge pins >would be parallel and in a vertical plane; they would also be in the same >plane as the line of the bridge notch for this note; this plane would be >perpendicular to the speaking lengths of the strings as well. The question >would be, should the front row of bridge pins lean left or right, not fore >'n' aft. The answer is, I believe, that the front row of pins should slant >down to the right (leaning the drill to the left); in this way, the bottoms >of the pins will be somewhat closer to the center of the bridge's width than >the tops of the pins are; this is a stronger construction than leaning the >pins the other way, with the bottoms pointing somewhat outward, toward the >edges of the bridge. The difference would be most dramatic in the tenor >region of a long piano, where the bridge is running more nearly fore 'n' aft. > And the difference would be least dramatic in the high treble where the >bridge runs more nearly left 'n' right; even here you might as well angle the >same way, for the same reason, and for uniformity with the rest of the piano. > >I don't think I've ever seen a grand bridge organized otherwise, although I >suppose it could be. An upright, when lying on its back, will usually >(always?) have its pins leaning in the direction opposite the grand's pins. > The same considerations prevail, but the bridge curve is in the opposite >direction compared to the grand. > >Hope I haven't confused the issue more in trying to describe this principal. > >- Tom McNeil - >Vermont Piano Restorations > >P.S. I agree with Don Mannino's comments, too. > >Tom, I am the newsletter editor for the Indianapolis chapter PTG. I found this reply interesting. I would like permission to print it in the December issue of the Newsletter. Please let me know as I am prepareing the newsletter now. Thank You. Mike Cook A440@Iquest.net
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