----- Original Message ----- From: "gordon stelter" <lclgcnp@yahoo.com> To: "Pianotech" <pianotech@ptg.org> Sent: May 15, 2003 1:51 PM Subject: Re: Plea for help ( last time ) nasty Baldwin SF grand treble.(so-called "Resonators") > Yes, apparently. I haven't gotten back to the piano > ( will do that tomorrow ), and I will try temporary > tape on the waste ends to observe the effect, and I > did just find my own personal archives on this subject > from the last time I griped about it. > ( Suggesting string leveling, drenching the hammers in > acetone, a reference to Susan's 2000 article on these > particular beasts, etc.. > But I would still appreciate your additional > comments, if you have any. > Thanks! > Gordon > The front termination piece used on the SF-10 and SD-10 was (is) basically a good idea. The problem with it is that, for the length of the frontscale, the string termination angle is too shallow. Or you could say that for the string deflection angle the frontscale is too long. The two are related. As with the traditional "tuned-duplex" front scale configurations this combination makes the piano very susceptible to string noises of various kinds as it ages. Sometime even before it ages. That there was string noise problem was discovered early on and it was especially prevalent on certain notes. So these notes got a slightly modified piece--the frontscale was made slightly shorter (from approx. 48 mm to approx. 42 mm) and the deflection angle was increased (from approx. 16º to approx. 18º. Had the entire set been changed to this configuration the problem would have been reduced to a manageable level. But they were not so excessive string noises continue to be a problem with this design. (Because of the screw hole locations it is not possible to interchange the two.) There are two solutions. One is a stopgap but is fairly easy to accomplish. It helps to reduce the various noises, but does not really solve the problem. The other is almost 100% effective and is permanent but is somewhat expensive and much more time-consuming. The first is to simply insert a piece of either very hard stringing felt or leather beneath the strings just above the front screw. This should be thick enough to actually deflect the strings somewhat when they are up to pitch. The second is to grind off the front bearing bar and replace it with a piece of 5/8" (16 mm) half-round brass extrusion. This increases the string deflection angle to approx. 21º and reduces the frontscale length to approx. 42 mm. The result is a much cleaner and efficient front termination. The noises will not return. Period. The only difficulty will be getting the front string bearing bar, or riser, removed. These things are hardened. Our machine shop bitched and moaned and sent us a big bill. (When I refer to the front of the termination piece it means toward the front of the piano.) Del
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