How to position the bridge?

Posted by Denis U on February 21, 2016 at 9:26am

I'm doing something new to me, and I really don't want to screw this one up as the box was a present from my better half, so I figure the better I make it, the more onside she'll be!!

It's a through neck and I'm using a screw down hard-tail bridge similar to this one. I am thinking that if I set the saddles at the mid-point of the range, measure the scale length from the nut to that mid-point and screw the bridge down, that's the best guess I can make and I should have enough adjustment to get the correct intonation.

Any ideas, comments or experience would be really welcome. Thanks in advance

Denis

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Replies

  • Paul Craig March 7, 2016 at 4:57am

    The high G and low E strings seem to be the strings that end up needing the most length and high E needs the least on all the scales. So your choice of strings(gauge or which ones out of a set of 6) can be a positive or negative on your bridge placement.

  • Fomhorach March 6, 2016 at 5:18pm

    Also be mindful if the strings are plain or wound. It makes a difference. If you look at a properly set up electric, as the string switches to a wound string the bridge does not follow a straight line but bounces back. 

    I don't know why you guys think a 25" scale would need less adjustment than any other scale length. On a 24-26 scale the string weight and string/fret height distance has a bigger impact.

    • Paul Craig > Fomhorach March 7, 2016 at 4:40am

      Was going by experience. I have a 24.75" scale guitar, have had many 25.5" scale guitars(still own 2), 2 - 25" scale guitars and 3 - 25" scale CBG's. Out of all those, the 25" scale instruments have had string lengths that were the closest to each other after intonation. The other scales had strings that were further apart in length after intonation.

       Also, Lighter gauge strings vs heavy gauge strings. Gauge size can change the lengths of string adjustment too. You can add that to the wound vs solid string mix requiring more adjustment space scenario.

  • Denis U February 23, 2016 at 9:45am

    Thanks Guys so far.

    Let's see it I have got things right. The scale length is 24.75 inches. With the saddles as far forward as they'll go, they are 1/8" behind the front edge of the base of the bridge. The saddles will go back 1/4". So I am thinking from what you have said that if I set the bridge to be at scale length when the saddles are fully forward then I should be OK. As I write that, I am thinking even a mm or 2 under scale length?

    Am I close ?

    • Paul Craig > Denis U February 23, 2016 at 12:18pm

      http://www.stewmac.com/FretCalculator The bridge placement info will be at the bottom of the page.

    • Denis U > Paul Craig February 23, 2016 at 1:30pm

      Thanks Paul. I'd only used that for a Strat copy I built. Because fir this one I'm using a non-standard home made bridge, I just hadn't thought to look at the StewMac page. Looking at accoustic rather than electric gives me a good answer

  • Paul Craig February 22, 2016 at 3:44pm

    The Stewmac fret calculator shows the bridge placement for that type bridge the distance from the fingerboard side of the nut to the front mounting screws of the bridge.

    The way Don Tucker mentioned will work on a scale that doesn't require a lot of adjustment to intonate like the 25" scale, but for a 24.75" or 25.5" you'll need the extra room for more adjustment.

    So it would be better if we knew what scale you were talking about first.

  • darryl kernaghan February 22, 2016 at 10:59am

    John's right to my knowledge,NONE of the strings will be less than double the dimension to the 12th fret,so just a mm or so short of that should cover

  • ChickenboneJohn February 22, 2016 at 10:37am

    Sorry to tell you, but that's not the best way to do it folks. For any given scale length, the compensation will always involve making the string longer. Set the saddles so that they are pretty much as far forward as they will go, whilst still making sure the screws are fully engaged in the saddles. You may want to wind them back a wee bit further, to account for any inaccuracy when you screw the bridge down, but no more than a couple of millimeters. If you set the saddle at exactly the theoretical scale length on the high string, you will still need to lengthen the string length a little before you get to working on the compensation to get it to play in tune. By all means give yourself a little room for error in fixing down the bridge, but if a bridge is in the right position, you will never need to shorten the string length to get it to play in tune.

  • Denis U February 21, 2016 at 6:49pm

    Thanks guys. Good to know I'm on at least one right track!!

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