Jerryc41
Well-known member
How can I get the bridge centered and level, short of just winging it? With the curved body, there's no straight line to use as a guide.
I do it a bit different than these guys I guess. I lay a ruler along the edges of the fretboard, then measure from the nut along the imaginary line formed by the ruler extending down over the top, to the desired bridge placement (1/4" ahead of the scale length for my bridges). This gives me two points on the top effectively centered on the fretboard. The bridge gets placed with those points right on it's front edge, centered on them from side to side.
Similar here. I mark the position by damming the area with masking tape. I measure length first with the steel ruler clipped to fretboard providing just enough downforce so I can put a piece of masking tape across the front of the bridge. I then project the sides of the fretboard as above onto that piece of masking tape, centre, cross check against alignment of strings on bridge vs fretboard with steel ruler, cross check length. Tape on side positions check length. Check string alignment. Check height. Check length again. Check everything I haven't thought of. Check measurement of nut to 12th fret is just a tad less than the measurement from 12th fret to saddle position. Check allignment of strings. Check measurement of 12th fret to saddle position is just a tad more than the measurement from nut to the 12th fret. Put tape behind the bridge. Cross check the tape outlines the bridge placement. Check everything above again.
Glue and clamp the bridge in position.
When the glue dries, wonder why it is in the wrong position.
Try again, get it right the second time..
How much is a tad?
Putting double sided tape on the bottom of the bridge while doing all the alignment and measurements helps keep it from moving by accident while fiddling around with it.
As much as you need for intonation
On a tenor I shoot for the saddle center line to be behind the scale length by .1". With a 1/8" saddle that gives you an intonation "compensation range" of from .0375" to .1625" behind the scale length.
When you say "behind," you mean the saddle is 1/8" farther from the 12th fret?
Correct. The compensation distance is further from the nut. The distance depends on your scale length. I use 3/32 on a 17 inch scale tenor sized instrument. This is a "rule of thumb" measurement or a "tad" which means it is inexact. And then we get into the subject of compensation and intonation and all that which has been covered MANY times on this forum.
Are you making your own bridge? If so, you can opt for a thicker saddle to give yourself more compensation range.
Or just stick with what ya got and put it "a tad" longer than 17" if you're not too concerned about intonation on the higher frets. Really, there is a degree of wiggle room in terms of scale length/intonation since you can adjust the witness point forward/backward across the thickness of the saddle depending on how you shape it. But the thing you definitely don't want to mess up is the side to side placement relative to the fretboard, there's not much margin for getting it wrong before the instrument becomes unplayable, and there's no real way to fix it if you get it wrong other than popping the bridge off and regluing it, which is a pain.
Just to make sure that everything is spelled out.
You are trying to figure out where to place the "bridge", but all the key measurements that you need to take into account are to the "saddle".