---------------------- multipart/alternative attachment What do you think explains the response that (Ed Foote? don't remember who it was exactly) got when he placed some wedges between the gaps and board and reported an appreciable loss of "tone". David Love davidlovepianos@earthlink.net ----- Original Message ----- From: Delwin D Fandrich To: pianotech@ptg.org Sent: 7/15/2003 9:43:23 AM Subject: Undercut bridges I tried to reply to this thread earlier but for some reason my server couldn't get it out. It kept bouncing back. I'll try it as a new message. Del ----- Original Message ----- From: "David Love" <davidlovepianos@earthlink.net> To: "Pianotech" <pianotech@ptg.org> Sent: July 12, 2003 10:30 AM Subject: Re: Strange bridge in a Steinway > There seem to be a few theories about these gaps which appear on various > models and not on others. I've often wondered whether the theories hold up > in practice. I can't see that they do much of anything. The idea that the bridge is too stiff and these cut-outs somehow reduce the overall stiffness doesn't hold up in practice. Remember there is also a large block on the back side of the soundboard with a dowel coming up through it and the soundboard and into the bridge between each of the two ribs. What is the purpose of these? To add back the stiffness and any mass lost by the cutout? As well, consider the grain direction of the soundboard. It very nearly parallels that of the bridge so either with or without the cutout it's stiffness has to be included in the overall consideration. Finally, reducing the stiffness of the bridge through this region is not something you really want to do. Not unless you are deliberately trying to come up with a percussive sound having a short fundamental sustain. The reason we put bridge extensions on the end of the tenor bridge is to make sure the thing is stiff enough down at the end. A better solution to the tone problems through this region would be to fix the scale. > > I've heard some mention that when reusing the old bridge on a > new board that they fill these areas. Yes. This is our normal practice. > > In light of a discussion awhile ago > about the bridge's contribution in general to the stiffness of the board, > it would seem that these gaps are of little consequence. If they don't > have any real benefit, do they do any harm? That is, do they effect the > function of the bridge or board in any negative way possibly. As Roger J. > mentioned, I like the model O as well. The questions for me are: what in > that model is really contributing to the specific performance of that > piano, what might be inhibiting better performance, and what really doesn't > make any real difference? As I said, I doubt they make any substantive difference either way. At best I can't see they do any good and at worst they might inhibit transfer efficiency somewhat--especially down toward the fundamental--though I doubt this has been proven beyond doubt. Del Delwin D Fandrich Piano Designer & Builder Hoquiam, Washington USA E.mail: pianobuilders@olynet.com Web Site: www.pianobuilders.com Delwin D Fandrich Piano Designer & Builder Hoquiam, Washington USA E.mail: pianobuilders@olynet.com Web Site: www.pianobuilders.com ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/25/e5/a1/f0/attachment.htm ---------------------- multipart/alternative attachment--
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