Scale length measurement

[pauly]

I am setting intonation on a guitar thats giving me a little grief about being in tune in an open chord and not in tune further down the neck so I took a measurement on the bottom E string to check proper scale length before intonating..which is something I havent done before. I'm measuring from the center of the nut to the center of the 12th fret, then from the center of the 12th fret to the center of the saddle. It's off some, not much though. Just for the heck of it I measured two more guitars...neither one of those measured the same either. WTH? Is this common? Anybody else noticed this on their guitars? Should I be measuring from the bottom of the nut or the center of it for a correct scale length? Am I correct in assuming that unless the scale length is perfectly exact that perfect intonation cant be attained?

 

I'm not a luthier (obviously) but have always tweaked intonation when needed..but I have never actually measured for the correct scale length before intonating..which might explain why I have tuning issues with a couple of my guitars. Input from any luthiers or those who are very experienced in this appreciated.

[rct]

1.) You don't "tweak" intonation, you set it.

2.) You don't measure in order to intonate, you use a good tuner to intonate.

3.) You intonate by making the open note and the 12th fret note the same.

4.) You make them the same by moving the saddle forward to compensate for a flat 12th, backward(away from the nut) to compensate for a sharp 12th.

5.) This movement actually adjusts the scale length to be as near as exactly the same between the nut and the 12th and the 12th and the saddle as possible. As possible because:

a) These physical differences can be difficult to measure.

q) The tuner hears two notes, if they are the same, the overall scale is fine,no matter what the two halves of the scale length measure.

 

6.) Yer welcome.

 

rct

[Ryan H]

Scale length is the distance between the fretboard-side of the nut and the center of the 12th fret, times 2. Each saddle could be at, above or below that number; it depends on gauge of strings, tuning, neck angle, nut cut...both of my guitars are dead-on in terms of scale length (My Charvel measures 12-3/4" from nut to 12th, x2 is 25-1/2". My Gibson Melody Maker measures 12-3/8" from nut to 12th, x2 is 24-3/4.

 

-Ryan

[pauly]

Thanks guy's..even if given with a little sarcasm lol. I can dig a little joisey humor. I found a couple of reputable factory guitar sites that covered it pretty well....which I shoulda done to start with. I dont think I'd want a guitar w/o an adjustable saddle bridge ( think prs ).

[Jimi Mac]

1.) You don't "tweak" intonation, you set it.

2.) You don't measure in order to intonate, you use a good tuner to intonate.

3.) You intonate by making the open note and the 12th fret note the same.

4.) You make them the same by moving the saddle forward to compensate for a flat 12th, backward(away from the nut) to compensate for a sharp 12th.

5.) This movement actually adjusts the scale length to be as near as exactly the same between the nut and the 12th and the 12th and the saddle as possible. As possible because:

a) These physical differences can be difficult to measure.

q) The tuner hears two notes, if they are the same, the overall scale is fine,no matter what the two halves of the scale length measure.

 

6.) Yer welcome.

 

rct

 

That!!!

 

I've never "measured" intonation in my life... I never even conceptualized it as a measurement... I simply set it to accurate by note/pitch accuracy with a tuner.