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Dear Friends,

I am wondering for to how thin to make my wings on a Torres bridge? I have been said 3.5 - 4.5 mm? What is the perfect thinness?

Thanking you,

Eugenio

What Filippo said. Basically it depends on the density. With very dense rosewood (about 1000Kg/m3) you need to go down to about 3.5-3.7 to get a decent weight of 20-22g. 4mm works well with regular rosewood (800-900Kg). Of course the final weight also depends on how you work the other variables.

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Build log

That makes sense.

As for the 'perfect' thickness, like for anything else related to guitar making, you'll find as many different answers as there are luthiers making classical guitars!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

I agree with Alexandru in that the weight of the bridge must be taken into consideration. I make mostly flamencos, which seem to work best with a light bridge. So, I thin the wings until I get a weight of 17 g. However, most of the books and plans I've seen indicate a thickness of 4 mm.

Good luck,
Max

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Max Bishop
Brighton, Michigan

As I consider the bridge an exterior top "brace" as well, I'm more concerned with flex than with weight.
Around 3mm thickness for the wings seems to produce the right amount.
If I were to weigh my bridges (which I don't) though I'm sure they would fall into the parameters stated above.

I agree with David also.
I do not weigh mine but 3mm thick is the most I leave the wings.

Mike

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Mike Collins

Filippo Morelli wrote:
"This is a wise observation (it's a brace). The bridge also dissipates the string energy which is a primary function."

I usually consider the primary function of the bridge as being to set the length of the string by keeping most of the energy in it. That's sort of the inverse of what you're saying, but I guess it's all in one's perspective.

The 'right' thickness for the bridge wings is the one that works best with that top. In it's secondary function as a brace the bridge has an effect on several top mode frequencies, particularly the 'monopole', 'cross dipole' and 'cross tripole' modes. The first and last of those are major sound producers, and altering the pitch or mass of them can have quite an effect on the sound of the guitar.

Some makers like to start with the bridge wings uniform in height and fairly tall; say about 4mm. Once the guitar is assembled the wings can be thinned, particularly at the tieblock end, to alter the stiffness of the bridge and (usually) lower the pitches, and increase the activity of, those modes. Obviously this has to be done carefully, but it can be done while the guitar is string, and even after it has been finished, so you can get some immediate feedback on how you're changing the sound. It'sd fairly easy to French polish the bridge wings when you're done, and nobody knows that you didn't make them that way to begin with.

Hi all, just as a follow up to this discussion and out of curiosity I weighed a bridge (which I had never done before), this one to be used on my latest guitar.
This is my typical design which I've been doing for a while now and is in Indian rosewood

Size: 190mm X 28mm

Weight= 16 grams