Scale length question

[Howard Williamson]

Hi there;
So, I'm building my first guitar from Johnathan Kinkead's book. I'm getting ready to cut fret slots. I'm thinking I'll make a jig similar to the Stewmac or Lmi ones to use in my milling machine W/Digital readout (.0000" resolution) but without a template, using the DRO to feed it over.
But first a question about scale length. J. K. refers to a 25.4" scale length (645.2mm) and starting from the "zero fret position" but doesn't locate that position on the plans. Its at the nut but where on the nut ?
If I measure directly on the full scale plans, it seems to be at the middle of the nut but presumably the printing process may have skewed things a bit because if I measure 322.6 mm each way from the 12th fret, I get middle of nut at the top, but an equal distance toward the saddle puts me a couple mm past his "scale length line" on the plans or a couple mm short of the saddle at the center line.
Can someone please tell me what's correct here ?
Thanks.

[Greg Robinson]

Hi Howard,

The scale length starts from the fretboard side of the nut. All the fret positions are measured from there. The saddle sits a bit further from the nut than the true scale length, and is angled further away on the bass strings, this is compensation, and is required to allow the strings to play in tune (without the notes get sharp as you play up the fretboard).
It's been a while since I read Kinkead, but I'm pretty sure it's explained in there.

Good luck with your build!

EDIT: also, you should not try and use plans as a template, they are meant as a guide, and you should always make your own measurements to ensure accuracy. Printing deficiencies mean that they may not be correctly scaled.

[Steve Senseney]

Wfret is a program that will print out your scale. You still need to measure to be sure that your printer is exact.

It was available on the mimf in the past, but until the archives and library get on to the new forum, I am not sure it is available here.

I googled for wfret.zip and found a site that has it for download. I don't know that they credited Jon Whitney for writing this.