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Hello,

I've been reading this forum and found a lot of the conversation thought provoking. Some of the books that are referenced such
as Gore and Gilet have been influential in my work. One of the places where I felt these books lacked was a proper solution to intonation problems.
The process described by Gore and Gilet involves either using a formula or creating a guitar mockup on a rail with the exact amount of string tension. We found both of these methods to be lacking. If the amount of compensation is found by using a forumula, then translating it onto the gutiar will be hard. Shaving away precise amounts of the nut and saddle is not easy to achieve. Another factor that we have to take into account is the humidity changes that occur season to season. These will change the guitar and the intonation will be off.

I have invented a new bridge and saddle design that provides adjustable compensation. Here is what they look like.



It's a simple idea with a lot of precise routing behind it. The bridge saddle nuts can move in the channels. Each nut sits on it's own plate that can be removed. When the strings are off there's a spring that holds the nut in it's position. They can be moved back and forth with a small fork tool with the string tension on. The split nuts can be removed and changed with a screwdriver. There is a magnet holding it in place when the strings are off. This is how it works in short. We use a CNC to make the peices of the bridge.

I wrote up a full article exploring the problem of intonation and how to correct it. It's too long to post in it's entirety here. There is a video example of intonating the bridge and changing the saddles at the end.

fine guitar Intonation

How much does the entire bridge assembly weigh?

Very cool idea. Back in the 70's when I attended Charles Fox's Earthworks school, he was using a 1/4 inch wide saddle and a very precise method of intonating at the bridge, taking advantage of the width of the saddle. Also, being a banjo maker, Stelling's compensated nut made good sense to me. Combining the two basic ideas into a very flexible system looks very promising!

Dave

Why not take it a step further and combine it with Thompson's enharmonic fretboard. No sense half steppin it.

That's pretty cool. I wonder what individual isolated saddles does to the tone though?

Although this probably works very well, I'll be very surprised if it catches on. I mean, that's got to be expensive and out of reach for the small hobby guys to do sans CNC though this could certainly be done on a hobby sized machine. I'm just saying, count me out on this one. I like the old fashion straight style of nuts and saddles.

Good luck on it. I'm sure there are plenty of forward thinking guys out there that will love and have to have this.

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Hutch

Get the heck off the couch and go build a guitar!!!!

That's an interesting design. It doesn't look like it would have much impact on the weight of the bridge. In the video, you show adjusting the high E saddle with a push stick. Was that done under full string tension or did you detune a bit first?

I'm guessing that changing the action would be fussier than with a one-piece saddle.

The design reminds me of some other bridges that I've seen with saddles that are adjustable for intonation.

Three guitar bridges:





And, a couple ukulele bridges:

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

The uke bridge is very interesting, could be good for switching between low g and high g.

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That is a similar design. In the video I didn't detune. It's easier to change the action. Instead of needing a new saddle at a different height or inserting a shim underneath the whole piece, which we can still do, we can create a new saddle plate that is at the desired height.

Making your own adjustable bridge is going to be too difficult for someone without their own design and cnc. We offer our bridge so that people can use it.

The bridge, plates and saddle pieces weigh around 38 grams and the saddle plates and nuts weigh 14 grams.

I'm not sure what the effect on the tone is. I'll make a few recordings and compare, I could make a straight saddle sitting on the saddle plates pretty easily to compare them without building a new guitar with different features.



I think alternative turnings are a great use for the bridge. We just gave a bridge to someone building a tenor uke, I'll ask them to try this out when her build is finished.

So do you find where the right intonation is and then glue the saddle in or something? How does the saddle stay in place during a string change for example?

Add to that question, how does the. It stay in place while tuning?

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

That is the key of the invention. There is a spring beneath the nut that lifts it into the channel when the tension is off. There is a guitar string glued into the bottom of the nut. When it is being tuned there is enough tension to hold it down.