MIMF

When measuring scale on a 24.9"
Do you measure from the front edge of the nut to the 12 fret or do you measure from the center of the nut?
Thanks Dave

No matter what scale it is, it is the working length of the string that we are concerned with. So, you want to measure only the part of the string that will vibrate and eventually make the tone you are looking for- so measure from the edge of the nut that lies toward the saddle.

Thanks Mark.
Keep that thought and now for the correct placement of the bridge I will measure from the 12 fret to to the front slot of the bridge + .10" of an inch and the measurement will be at the front slot of High E?
Dave

Well, the 12th fret is the halfway point from the nut to the saddle. The distance from the 12th fret to the saddle is the same as from the 12th fret to the nut plus the added compensation.

I'll note that measuring the scale length on an existing guitar can get tricky. Some folks are compensating the nut as well as the saddle; shortening the distance from the nut to the first fret. The distance from the nut to the center of the 12th fret will not be half the scale length in that case. If the frets are straight it's a pretty good bet that the distance from the 12th fret to the first fret would give you a correct reading: the first fret should be at .9438 x the scale length, and the 12th at .500, of course, so the difference would be .4438, and the scale should be 2.2532 times the distance from the first fret to the twelfth. This assumes the frets were cut correctly to begin with, and were not individually compensated, which may not be so.

Alan Carruth / Luthier

Another way to find the saddle location for instruments with nut compensation would be to measure from the first fret to the thirteenth fret, and use that measurement + compensation, to find the distance from the thirteenth fret to the saddle .

To add yet another complication, sometimes the saddle leans back, so the compensation increases with the saddle height, and you have to take that into account when locating the bridge.

Thanks for the indepth.
The nut is 90* to the fret board the 12th fret is 12.45" from the nut the saddle is where I am confused.
the saddle slot is cut at an angle.
At what point do you measure the location of the saddle?
If I use the location of the 1st string the hi E string, then the low 6th string is approximately .20 " longer.
I'll set the saddle at + .10" compensation when I determine the exact location of the measurment point on the saddle.
Thanks Dave

+ 0.1" in the middle (more or less, more for me less for others)

Clear as mud, eh?

There is a good diagram illustrating saddle compensation here --> http://www.cumpiano.com/Home/Articles/A ... DDLE~1.HTM