Acoustic Guitar Construction

The lever action of the strings over saddle will "roll" the front edge of the bridge "down" -- so the height of the saddle and width of the bridge will factor as well -- I am sure there is a down force, torque, tension, weight equation. But I would think is would be easier to simulate the bridge saddle lever assembly and just apply the string tension using an in-line scale as your gauge.

Here's another approach from Al Carruth:
"Suppose you have a 30 degree break angle over the saddle with your 'normal' setup. The resultant of forces on the top of the saddle is in a line that points 15 dgrees forward of vertical: the bisector of the break angle. If your saddle was on that line, angled back by 15 degrees, there would be no net tipping force on it. I use a nine degree back angle, which is not enough to eliminate the tipping force, but does reduce it considerably."

Ken - just read your comment. Thanks, I'm thinking about it....


edit: I thought I'd struck gold, but this formula is only for archtop instruments:
http://www.liutaiomottola.com/formulae/downforce.htm

BTW - here is an excellent string tensions calculator, you can design your own custom set and do lots of other stuff, and the calculator will give you results.
http://www.stringtensionpro.com/Home

I agree there is a downforce, but it pushed on the "saddle"-area. The ball-ends produce an upforce. and because these points lay quite close to another, the result to the center of the plate is almost equalized. Leaving the rotating force dominant. If the ball-ends are at the end of the top (like with an archtop) on the center of the plate, there will be only downforce to that center. 'Cause the pulling forces are out of the way there.
My 2ct.
Herman
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EDIT:Again, wrong. sorry.

http://www.esomogyi.com/principles.html

I would want to measure the vector force -- as mentioned earlier.

Thanks guys. You've helped me to see the picture more clearly.

Your right Ken. That is the way. But I think, Dave and I, we misunderstand each other. This because if you talk force, you have to be specific about what place you're looking at. In the vectorpicture it is shows the forces to the top of the saddle. Dave refers to the "top" as a whole thing. But the surface of the whole top is an area where different "vectors" come into place. Depending on what point you're looking at.