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I am working from a Stewart MacDonald Herringbone plan that indicates a 25.340” scale length. On the plan, the scale length is measured from the nut to the FRONT of the saddle on the treble side. There is also a measurement of 25.465” (compensated saddle distance) to the BACK of the saddle on the treble side. Using the Stewart MacDonald Fret Scale Calculator on their website, the distance from the nut to the saddle “BREAK-POINT” is given as 25.429” to the treble E and 25.554” to the bass E. Now there seems to be a bit of inconsistency so I called StewMac and they tried to be helpful but left me with some doubt.

Those of you with experience and an eye for detail:

1.Do you measure to the front of the saddle or to the middle of the saddle (I don’t establish the break point until final intonation after the strings are up to pitch)?
2.Do you measure down the string path or down the middle of the neck and then draw a perpendicular line at the saddle?
3.What measurement would you use to the saddle on the treble and bass sides.
4.Is there a conversion constant to convert the decimals to 32nd or 64th inches?

Well, I dont measure from the nut at all. Since I comp the nut forward approx 1mm (oh yeah, I also work in mm, its way easier than imperial for this), I measure from the 12th fret, centre of the fret, to the centre of the saddle slot down the centreline of the fretboard (got all that ??). Now, I use half the scale length, plus 2.5 mm for comp to this point - the saddle slant (mine is 2.5mm) then gives ample room to manoevre to get the intonation set.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I believe you should measure to the centre of the saddle, and measure down the centre of the fingerboard rather than the string path.

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David White, Toronto

"All my favourite singers can't sing."

I use a saddle matic also, and measure from nut to front of saddle at the center then add 1/16". My slot is cut beforehand and I use a 1/8" saddle. That allows for any fine adjustments. It has worked very well for me, and I, too, use the same plan from StewMac.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

EDIT


I actually measure from the nut to the 12th, then 12th to front of saddle + 1/16".

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

Yep, the measurement should be down the middle of the fingerboard in a straight line from the nut to the bridge. Then run your line perpendicular left and right, making sure you're perpendicular to the centerline of the top. Once you've got your true scale length line located, you can move it one way or the other for your saddle location and compensate from there.
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

i have not used a ruler to determine saddle position for many years, rather only using the rule to locate the bridge then routing the saddle to suit the required intonation after the bridge is affixed.

when i did measure, i did so on the string path as your plan indicates. after all, the compensation is on the string length.

are you using a ready made bridge? if so then you are stuck with the saddle slot geometry already routed. using the plan dimension to locate the bridge and gluing the bridge square is all you can do.

there is no conversion factor to convert decimal inches into 1/64". that is why you should have a rule graduated in 0.01" if you are going to build guitars, or as someone else mentioned above work in metric. the sort of rule you want is a 16r, which has both 0.01" and 1/64", and for guitar building you really need a 36" version. an 18" or 24" and a 6" will serve to make your task that much easier as well.

1/64 = .015625

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Say what you do, Do what you say.