bridge placement

axisus

I'm planning on putting an LP type bridge on my tele build as per the picture below. How would one calculate the correct position for a 25.5 inch scale length? Would one just measure to the approximate centre? Seems like a dumb question, but I'd rather ask rather than dive head first into a cock-up!

WezV

Put some masking tape on the body down the center line and across the approximate bridge location

Measure the scale length down centre line. you know its 25.5" from fretboard side of nut to bridge location so measure this first.  You can then double the nut to 12th fret distance to double check you still get the same measurement.  this isn't really needed on a known scale length but its a measure twice cut once scenario... and if you have a couple of different reference points to measure all the better

you should now have a mark on your centre line.  draw a line cutting across this at right angle.

Put the bridge on that center line you just drew.  make sure its nicely centered.  use a long straight edge to check string alignment on the outside strings and once you are happy the bridge is in the right place mark the centre of the post holes on that bridge line you drew

this is the important bit - you need compensation and this means a slight bridge angle.

the treble side bridge post will need moving back 1.5mm on the treble side and about 3mm on the bass side... so measure back towards the strap pin from the bridge line posts you marked..  connect these dots with a straight line, this should now show the normal bridge angle you expect to see.

replace the bridge on this angle bridge line and check the holes you place marked are in the right place.  check string alignment and scale length again (adding on the compensation amounts above).  drill once happy.

I will do a step by step with diagrams later as its much easier to show than describe

ICBM

A good final double-check before you drill is to set the bridge with the top E saddle as far forward as it will go, put it on the body in the marked position and check that the distance from the front face of the nut to the front face of the saddle (ie their closest faces) is the same as the scale length. The saddle will never need to be forward of here no matter how light the strings, and that will give the right adjustment range for anything heavier.

TTony

Have to wiz Wez, specifically the measure twice (from different points) cut once comment,

WezV

ICBM said:

A good final double-check before you drill is to set the bridge with the top E saddle as far forward as it will go, put it on the body in the marked position and check that the distance from the front face of the nut to the front face of the saddle (ie their closest faces) is the same as the scale length. The saddle will never need to be forward of here no matter how light the strings, and that will give the right adjustment range for anything heavier.

totally correct, although i usually advise starting with saddles about 7/8ths of the way forward, rather than all the way forward. 

They should never need to be closer than the scale length line, but in real life it sometimes pays to allow a little fudge room. 

I do that for all bridges, but on fender style I often allow a little more (more like 3/4" of the way forward) to make sure there is good tension on the intonation springs with the saddle set bang on the scale length

WezV

so with the method i have described i have not adjusted the saddles as stated above.  that's because I know that doing it this way with a tune-o-matic on a standard scale length will give a nice placement of the saddles.  I always do the adjust the saddles thing when starting with a new bridge, and it is a good measure thrice check even with known measurements

anyway, some pics

Always start with a center line - make sure the neck is mounted so you are totally confident it is the center line, you can measure down the middle, and down the side of the neck to establish its all lining up

measure from the fretboard side of the nut the whole 25.5" or whatever you scale length is.  double check that this measurement is twice the distance from nut to 12th fret.  once happy mark your uncompensated bridge location

you can know place the bridge on that line, make sure its centered on the center line and mark the center of the post holes

take the bridge off and extend a line backwards from the marks you have just made.   measure back from the uncompensated bridge line as shown in the picture (not too scale!!!).   if doing a baritone of bass then these measurements will be different, but these will work for the vast majority of normal guitar scale lengths

you can now join those two dots to get a compensated bridge line

now get the bridge again, put it on the compensated bridge line, check again to make sure its centered.  you may find you need to drill slightly inside the  marks you just made as the angle as increased the distance between the two points.  its only tiny, and usually not an issue, but its worth checking again at this point.  remeasure the scale length and once you are totally happy - drill

axisus

Thanks good people. @WezV awesome answer, as always!

Andyjr1515

axisus said:

Thanks good people. @WezV awesome answer, as always!

I agree - one of the clearest illustrations I've seen, @WezV

Sassafras

Excellent diagrams. Many thanks.