Bridge measurements

mab

Hello,
I recently got some rosewood and a piece of ebony to carve several bridges of different designs and woods. It's so that hopefully in the end I will have a handful of bridges that color the guitars voice differently. I already have one finished, and while it didn't come out half bad, I want to try and improve on the next one. So I have a couple of questions.

Does anybody know of any domestic woods that might be suitable? I sourced some local locust to try that out and I know I've seen hedgeapples growing around here but I don't think they're native to the area.

What are the basic measurements that you guys use for the offset between the different string lengths when you're carving out a bridge blank? I guess that I am wondering what is the basic profile of the saddle that you guys use to compensate for the intonation.

How thick do you guys leave your saddles? I saw arguments for both thick and thin saddles. One side seemed to think that thicker saddles would mean more of the string was contacting the bridge and therefore would transfer sound better, the other side argued that a thinner saddle would mean a higher pressure on a smaller area. I personally shot for just wide enough to hopefully be able to make adjustments later.

The curve on the top for the different string heights, what do you guys use? On the one I made I cut the top at an angle so that the low E was 2mm higher than the high E and then sanded the bass side side slightly flat, the low E ended up being still slightly higher than the A next to it and then they proceed to drop in height in even increments. Has anyone made the low e slightly lower than the A? I'm not unhappy with the way it is now but would like to try something different on the next one.

Also, Would the compensation for the intonation be different enough between round cores and hex cores of the same gauge to require a different bridge?


Thanks again and best regards,
Michael

Jeff Moore

I don't know about local or even US woods. I use rosewood, not because I know its best, but because that's what I have and I like the results so far.

I compensate each bridge I make using my ear to get the 12th fret fretted and harmonic the same using the strings I'm gonna use. So I don't have numbers. I leave the bridge flat front to back so I can compensate by putting a short piece of string (I use a wound G as a mobile saddle) on top of the bridge and under the string I'm compensating. This way you can lift the string and move the "saddle" back and forth. Trouble is: If your action is raised by this "saddle", your stretching the string your intoning a bit more than you should, but this could give you the relative lengths of all 6 strings compared to each other and a reasonably intoned bridge. However:
I make the bridge slightly short (and glue a foot on it later) so the height is right for compensating and the finished bridge is the same height. Gluing a thin foot on later also allows you to hollow out the bridge very nicely too. Light = better bridge - better sound. As a rule, I wouldn't want glue in a bridge, but I do it for those reasons.

The "curve on the top for the different string heights" is tricky. Mine come out almost straight when I've found the best height for each string. However, I would never have the string heights in a verticle zig zag just for playability cuz it'd play hell with my picking. My right hand wants it as straight as allowable using the string tops as my guide.
The optimum curve when the bridge is viewed from the end(for me) winds up being less than 1/16" peak in the middle. Damn near straight.

I think the difference between different kinds of strings (of the same diameter) is very small unless you compare wound with unwound, in which case the unwound needs a longer string length.
But I've only compensated for Argies and a couple other similar gauge alloy strings. The other than argie (GHS mostly) strings seem reasonably compensated even when I've used the argies to "do" the bridge. Caveat: I've only done non argies twice or so, and that was a while back.

Hope that helps

mab

Thanks, that's exactly what I was looking for. I really like that mobile saddle idea, I was trying to measure it because I wasn't sure how else to come up with a profile but that sounds much better. Any time you can measure off of something like that rather than using a scale it always seems to come out better. If you ever feel like trying non-argies and haven't tried Philippe Bossets, I would really recomend trying them. Then again, I still on occasion come back to my senses and throw a proper set of argies back on the guitar so there may be no point in ever straying.

Jeff Moore

mab,
Glad to help. Being able to do my own bridges and set ups has been something I've wanted to share with others.
Having to pay $500 to get a guitar playing well is beyond my (and most folks) ability. Making bridges is a hurdle that most guys likely won't cross. I don't blame them, but you asked so it was an opportunity to set out my way of doing it. Not that its the best or only way, but its at least doable for those who want or need to do it themselves.