Bridge weight and dimensions

Shawn

Hi all, I've been experimenting over the last few months with different bridge designs and have some questions. I know each individual instrument is unique and tonally takes to different materials in many ways, but what is ideal for a bridge? I'm going to include some photos here of one of two bridges I've worked on, each made out of Rosewood, and each weighing in at only 4.5 grams. I know, in retrospective, this is extremely light for a bridge, but each guitar I've tested my bridges on have significantly increased in both volume and range of tonal colors. It got me to thinking if there is a certain weight that works best...in other words...is the lightest bridge possible the best or is too light not good either?

Anyhow, here are some pictures of one of the bridges (each bridge is identical, but one is currently now on one of my guitars). I've noticed that I can build them as tall as needed and it only increases their weight by around .5 grams. Basically, I took the Selmer (Dupont) bridge design and reduced any unneeded wood that isn't used to compensate and support the pressure from the strings and was able to get these bridges down to their 4.5 gram weight. The underside is extremely hollowed out and there is only minimal wood between the hollowed out underside and the top surface of the bridges.

Has anyone else experimented with this before?

Jazzaferri

With bridges the physics are quite simple the less mass the less dampening.

That doesn't necessarily mean the lightest bridge will have the balance one wants. In that area is part of the artistry of the luthier.

Bones

Shawn,

What tool did you use to hollow out the underside?

Thanks

Craig Bumgarner

4.5 grams! Wow! That certainly puts the bar up a big notch. Good job, to get any lighter, you'd have to drill holes through it like a violin bridge. I've never taken one much below 9 grams, you inspire me to try.

I use a Dremel tool with a conical bit and free hand it. Once the initial groove is in, the bit tracks easily in the groove.

Shawn

Craig, I actually use a Dremel tool as well and just eyeball it. I usually use two different bits, and then sand it out with 220 grit and finish off with 1000 and 2000 grit.

I'm actually working right now with what you could loosely call a prototype to see if I can get the weight down by another gram or two...I have some ideas which I think will significantly reduce the weight even more, and might even help the tonal characteristics. I won't know until it's complete and strung up, but I'm rather hopeful at this point. Basically, I'm trying to design one that will hold up under the string pressure almost to the point that it's going to collapse. So far, at 4.5 grams it actually sounds wonderful, but is far from the "collapse" point I'm trying to achieve.

pickitjohn

Way to go Shawn, are you making the bridge from stock or using pre made bridges?

I've had lots of luck messing with my bridges but the lightest I got to is about 8.5 grams.

I do notice I sometimes have a problem with one strings intonation and was wanting to understand how to make the proper compensation on the bridge. It seems like where the string should be there no material on the bridge.

Any help anyone?

pick on pickitjohn

noodlenot

Hi, nice mug you have there...

what´s the main difference you´ve noticed with your light bridges, if i may ask? i tend not to like too light bridges, but my lightest was around 8-9 g... i hollowed it with just a narrow chisel, so i guess i could take some more wood if i used a dremel (which is actually a pretty good idea).
if you want to make them even lighter, use another wood : padauk is lighter than rosewood, stiff and has low damping - could be worth a try. walnut is another candidate.

best,
Miguel.

Jazzaferri

I finally got around to checking out my beach selmac. 22 grams.....diet time methinks

Bones

I'll look for a conical bit for the Dremel. Is it made by Dremel or some other company?

thanks

Jazzaferri

Dremel market them. Think most of the consumer ones are made in Asia. The good carbide ones that are way more expensive to buy but stay shsrp way longer are us or european mfr

If you are just doing a few get the dremels.

Jazzaferri

Something that worked reSlly well at transmitting vibrations on resonater guitars is Osage Orange....it grows in the usa southeast. Light strong and really stiff resonant wood. Probably tend to the bright side.

Honduran rosewood resonates pretty well too.