---------------------- multipart/alternative attachment Ron & list - Somehow, my attempts to be non-confrontational and unprovocative seem to=20 have failed, rather dramatically! I don't know. How much of what I hear=20 in Ron's tone is my own misreading or projection? I tried to do two=20 things, maybe three, with my last post. I tried to be appreciative of=20 Ron's time and effort, I tried to rephrase some of my questions in response= =20 to his comments, and I tried to eliminate those issues that seemed to=20 digress too far from the point. Actually, four things. I tried for a=20 little levity too, but I'm afraid I have to acknowledge that, with this=20 medium, and my writing skills, I can't get away with not using <grin> or= :-). I won't ask any further technical questions. My objective here is to=20 understand the communication glitches, and to apologize for any role I=20 might have in them. At 07:30 AM 2/25/2004 -0600, you wrote: >>>The pin angle combined with the string tension and offset angle forces=20 >>>the string against the bridge top. It's a clamp system. >> >>This is a static definition. What I was trying to ask about was=20 >>"dynamic" coupling, that is, the interaction of the parts (string, pin,=20 >>bridge) in motion. > >Which was no where evident in the question. I'm sorry, That's why I rephrased the question. >>>>Does the front edge of the bridge play any role in defining the string= =20 >>>>termination? >>> >>>Yes. It's what the pin angle, string tension, and offset angle clamp the= =20 >>>string TO, ideally. >> >>I meant, does the front edge of the bridge have any effect on the way in= =20 >>which the various modes of string vibration evolve & decay that might be= =20 >>measurably altered by its absence? > >Again, the question you asked in no way remotely indicated that, and I=20 >don't have those answers in any case. I'm sorry, but while I acknowledge that, upon consideration, the original=20 question was overly broad, I find it a bit excessive to describe it as "in= =20 no way remotely indicated". I said in the intro to this series of=20 questions (which was not copied in Ron's reply) that I did not expect him=20 to be able to answer all of them, nor did I wish the burden of response to= =20 fall entirely upon him. >>What amount of negative force would be needed to overcome the design=20 >>parameters you have quoted..."10 degrees side, 20 degrees pin slant"? > >With a string at 160 pounds tension, with zero overall down bearing, 10=B0= =20 >offset, and 20=B0 pin slant, it would take about 23 pounds to push the=20 >string up the pin. With 160 pounds tension, zero bearing, 5=B0 offset, and= =20 >10=B0 pin slant, it would take about 10 pounds to push the string up the= pin. This is useful information. >>I recall some discussion about the bridge surface itself expanding upward= =20 >>(apart from the soundboard's upward excursion) and, in the process,=20 >>pushing the string up the pins. > >I've written about this before. Ron - At this point, why wouldn't you have elaborated a bit. You say=20 you've written about that, but you choose not to indicate, even in brief,=20 what you said or when. Wouldn't this have added something substantive and= =20 possibly relevant? >Suit yourself. I see way too much friction between the pin and string to=20 >allow the string to slither up and down the pin during play - unless=20 >something is seriously wrong. And if the string was, indeed causing a=20 >false beat by slithering up and down the string, the beat wouldn't stop=20 >when you place a screwdriver against the side of the pin opposite the=20 >string - which it typically does. The noise I observe and associate with termination deficiency at the front= =20 bridge pin is not the same as the false beats, which I find to occur mostly= =20 in the upper two or three octaves. They are different noises, with, I=20 believe, different sources. >>>Of course. But it's because you're inducing a curve into the string to=20 >>>force it down to the crushed bridge edge by tapping, not because the=20 >>>string has climbed the pin. >> >>Sorry, no. I have, with a magnifier and strong lighting, watched the=20 >>bridge-segment string set to the bridge surface from almost all the way=20 >>back to the rear pin. It can't be all about wood fiber crushing. Of=20 >>course, as I get older, and my eyes get worse, I can reasonably suppose=20 >>that I'll be seeing less of this. That's one solution! > >Most likely right. I'm just blind and don't know what I'm talking about. I believe my intended meaning was poorly served by my choice of words. I=20 had intended my comment to relate solely to my own experience of late,=20 having more difficulty seeing than I used to. Ron's comment seem to=20 suggest that he interpreted my remarks as being insinuatingly directed at=20 him, If that's the case, I sincerely apologize. Not only is that not who I= =20 am, but, frankly, such technique is beyond my rhetorical repertoire. >> From the rebuilder's perspective, and not just Ron N, : > >Whatever that means. Again, my language was ineffective in communicating my intent. I was only= =20 trying to encourage rebuilding-readers other than Ron's self to contribute= =20 some comments, not that his in put was to be diminished. Sorry again. >>Are you striving for positive downbearing (with positive front bearing)= =20 >>across the scale? > >Yes. Aren't you? If not, why not? > >>If so, do you know (by measuring) how often you do or do not achieve this= =20 >>goal? > >Always. Don't you? If not, why not? As I've indicated on more than one occasion in these, and other=20 discussions, I am not doing rebuilding. That would address the question of= =20 why not me. These statements by Ron are, I think, at the core of my=20 questions regarding negative downbearing over the recent months. If they=20 are representative of the approach adopted by this readership, they then=20 also represent an unfortunate indictment of much of the work (new and=20 rebuilt) that I have come across in my years in this business. So, thanks Ron, and others who have contributed thoughts along the way. David Skolnik RPT, DBH ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/d4/af/59/54/attachment.htm ---------------------- multipart/alternative attachment--
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