#31
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Braces stiffen the top, and will keep it flatter. It also can make the top more responsive to high frequencies. Without braces, a 1/8" top will distort some.
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There is nothing wrong with doing experiments; I have a few test mules myself. But the chances are, it has already been tried before. Quote:
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#32
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__________________
Fred |
#33
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Steve Klein borrowed the basic Kasha bridge design, making his own variation of it, without using the Kasha bracing system. Alan has cleverly suggested that one can stick tac putty on a guitar bridge - or elsewhere - to non-permanently add mass where ever one wants, in an effort to see what influence the mass has on response. Similarly, one could also use rare Earth magnets. |
#34
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You should have this in the OP. I wanted to call a wood rescue service to confiscate the wood in those bins/barrels.
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#35
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I'm going to guess that the reason why you are asking this is because you can then make the top as stiff as the board, or relatively stiff, and then once again it brings up your original point. And again I can only guess at that too, that your original point is why do acoustic guitar bridges even need glue when they are pinned down in the same manor as your board or even a braced thin top??? |
#36
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Wasn't this sufficiently answered in your earlier thread?
https://www.acousticguitarforum.com/...=544324&page=2 If you define a point of interest, I will draw you a free body diagram for a typical wood bridge on a thin spruce top. Your photo shows a system with a rigid (relative to an acoustic guitar) metal bridge on a rigid wood top. Those forces between the bridge and the top will be much different than a wood bridge on a 0.110" thick spruce top. BTW, trig is not required to determine actual forces. You can scale the force vectors if draw to scale. [IMG][/IMG] |
#37
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I have no guitar building experience, but I would think one thing you'd want to make sure of in any "normal" build is that the bridge is attached firmly (bonded) to the soundboard, so that the force from the strings is transferred (via the bridge) to the top.
So regardless of whether it's possible to glue (or screw or bolt) the bridge to the top, you would want to do it. Right? As I said, I have no experience, I'm just interested. |
#38
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I have plans for some of this wood . Most of it won't fit into any barrel I know of .
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#39
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I am of the opinion that bridge pins , which are anchored to the bridge , are a major contributing factor to the tendency of the rear of a conventional bridge to elevate . With the bridge being above the plane of the top as evidence . In none of the diagrams that I recall , do I see any consideration for the fact that a clamping factor exists from the string ends to where the strings break across the rear of the bridge . The torque is increased be the height at which the strings break over the rear of the bridge . by lowering that point this specific factor should be lessened while increasing the clamping factor . This all functions as a system . Bt stiffening the area where the bridge lies , torque will also be somewhat compensated for . With a stop in place at the front of the bridge , the tendency to move forward is eliminated and tension is resolved to the string ends under the top . Please forgive my lack of formal training and ability to translate my thoughts into scientific terms/jargon . |
#40
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Will a 12 fret 0 in German Spruce over Maple suffice ?
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#41
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Here's a long thread from years ago that discusses some of the points brought up here. It's a long read, contentious at times, and comes to no significant conclusions.
https://www.mimf.com//phpbb/viewtopic.php?f=3&t=1126 |
#42
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Most importantly: None of this changes the torque which causes the bridge south of the pins to lift. This torque will always be the sum of the string tension and the height of the strings above the top. There are several approaches to eliminating the bridge pins; none of them have any bearing on this truth. There are ways to reduce or eliminate torque on a top, but this is not one of them. After reading the previous thread, I see a source of some confusion. Quote:
Last edited by John Arnold; 12-18-2019 at 04:15 PM. |
#43
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The higher above the top (thicker bridge) the strings bend over the bridge toward the saddle, the greater the amount of torque generated at that point where the strings leave the pin holes. The metal bridge has a minimum height above the top. Thus, lower moment at the point of string bend than a wood bridge.
The further back (south) that the strings are from the saddle, the greater the bridge area that will be in compression against the top. Also, the clamping (vertical) force will be further from the saddle compression force line. The pressure at the bridge base will be more uniform due to the greater distance between the force couple. Remember that the bridge torque will belly the top and it will want to separate from the bridge at that edge. The bridge is significantly stiffer than the top. The tension in the glue will be maximum at the edge of the bridge as the top curves away from the rotating bridge and will want to peel and lift. You can’t reduce the total torque on a bridge system. You can modify the bridge shape, saddle, and pin hole locations to change bridge/top bearing pressures and tendency to lift. All of this can be modeled in modern design software with finite element analysis capability and provide whatever answers are desired. That, however, is beyond my ability and desire. (I finished undergrad engineering with a slide rule for personal computing. A room full of IBM mainframes and card punch entry was the other choice.) [IMG][/IMG] |