Bridge Doglegs, was: Spreadsheet info / Jason Kanter

[Ron Nossaman]

> For a vertically laminated bridge, in many cases, you simply cannot bend it
> that sharply.

Reasonable enough from a practicality standpoint, especially 
bending a big stack that will be cut into multiple bridges.


> For a cut bridge, the sharper the curves at the dogleg, the more material
> is wasted, in a production environment.  The sharper the curves, the less
> continuity of grain along the length of the bridge.

I'm not convinced that grain continuity along the bridge 
length is remotely a big deal. I build bridges with open ended 
laminations at the doglegs. (photo) It makes it easier to jig 
up for a one off bridge, and I can make whatever is called for 
by the log progression of speaking lengths. If there is any 
tonal penalty for doing this, I sure haven't been able to 
detect it. This should be  doable in production too with few 
problems.


> I am not entirely sure that there might not be a good acoustical purpose
> served by minimizing the dogleg.   I am getting into dangerous territory
> here, since I have no study to point to which would support this argument. 
> There must be some reason why the treble bridge is commonly undercut to
> make the gluing surface with the soundboard a smooth(er) curve.  I'm
> thinking that the more the long bridge snakes along the soundboard, the
> more its capacity to transfer its energy to the board is inhibited. (Flame 
> suit on.  Go for it!)
> 
> Frank Emerson

I undercut the treble section and front of the treble dogleg 
to get the bridge footprint as far away from the belly rail as 
I practically can. Other than that, I haven't been able to 
detect any indication that the soundboard cares one way or the 
other if the footprint doglegs at the break. Just my 
experience. Anyone requiring absolute proof is going to have 
to generate their own.

Ron N
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