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__________________
Fred |
#50
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edit:http://www.mimf.com/phpbb/viewtopic....=1126&start=20 It is a long thread, with a lot of the math guys contributing after page 3 or so.
__________________
Rodger Knox, PE 1917 Martin 0-28 1956 Gibson J-50 et al Last edited by Rodger Knox; 12-24-2017 at 11:07 AM. |
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Let's turn the question around. If you remove the strings from the instrument, other than gravity, what forces are applied to the bridge/saddle unit? If you reattach and tension the strings, other than gravity, what forces are applied to the bridge/saddle unit? What is torque and what is the relationship between force and torque? https://www.physics.uoguelph.ca/tuto...que.intro.html Refer back to the static force diagrams I posted previously: you'll see, diagrammatically, the applied forces and the torque they produce. |
#52
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Tension is the straight pulling force. Torque is the rotational force developed when tension is applied as leverage, in this case to the saddle's upper edge which causes the bridge structure to try to rotate around its base.
Let's agree to avoid bringing enertia into the mix. I AM relieved to hear that science bears me out. Merry Christmas, pilgrims. |
#53
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#54
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On a pinned bridge design, there are at least 2 fulcrums: the point at which the strings exit the pin hole and the saddle.
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#55
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__________________
Rodger Knox, PE 1917 Martin 0-28 1956 Gibson J-50 et al |
#56
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look...this is all mathematics, and therefor follows the terms of math.
"there can be only one" fulcrum in this model of torque and how it is applied to an acoustic guitar top with a pinned/unpinned bridge. the lever(S) are the paths of the string (I note there are 2 paths...one to the nut and the other to the balls of the strings). now, it has been decades since I've delved into anything more complex than trigonometry so I'll do my best to make any "arguments". from reading through the supplied links and images, I see 2 things I don't think have been fully discussed: 1: as I noted, I see 2 paths from the fulcrum and the applied torque would seem to be the differential between the 2 (if they are equal, then there would be no torque (?)) 2: I see H as being defined as the height above the top...I feel this is incorrect as the nut is going to be below that elevation, and to me the elevation differential of the top of the saddle and the location of the nut is what H should be defined as everything else follows directly from the numbers and is defined by the math of it all, and as such is incontestable...1 fulcrum. |
#57
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2: Covered in the response to #1, above. While there is mathematics involved, this is actually a physics problem in the area of mechanics, not mathematics. |
#58
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There is at least 1 change as the string exits the bridge and then another at the saddle. |
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You could apply all the torque you want to the saddle relative to the bridge or vise versa, but the saddle cannot move relative to the bridge anyway.
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#60
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__________________
Rodger Knox, PE 1917 Martin 0-28 1956 Gibson J-50 et al |