Nut-slot Direction

[Jim Bevan]

I have a Mann 5-string electric, on which the D string binds at the nut, making tuning a touch problematic. The angle of the D-string from the nut to the tuning posts is greater (both sideways and downwards) than on the other strings, and (graphite etc aside) it occurred to me: Does the slot have to be perpendicular to the frets? Is there a reason it should not be cut at the same angle, or, even fancier, curved?

[Tobin]

I've seen it both ways. The old standard is to cut the nut slots perpendicular to the frets. But some folks angle them towards the tuners, and I can see the sense in that. Either way, the string is going to have to bend somewhere. I like the idea of curving the nut slots to avoid a bend, but that would be a nightmare to get right! You could no longer use regular file, I'm guessing.

[multidon]

That is, of course, the elegant beauty of the snakehead headstock design. It gives your strings the straightest pull in perpendicular nut slots with little or no bending of the strings. Form follows function!

[Jim Bevan]

I like the idea of curving the nut slots to avoid a bend, but that would be a nightmare to get right!

I agree, but I also assume that with all the fancy inlays and scrolls etc, it would just be par for the course, and functional enough to be worth the effort.

[sunburst]

I like to cut nut slots so that they roughly bisect the angle of the string path from the front edge of the nut to the tuner post. That means the slot is angled downward toward the back edge of the nut and it is angled toward whichever side bisects the angle to the tuner post. Snake head or otherwise, most mandolin pegheads are similarly angled downward from the fingerboard plane, so strings must break over an angle at the nut and some of that angle is to the side with any "standard" tuners in any normal positions. When you think about it, a slot perpendicular to the fret has the potential to deflect the string from it's path to the tuner much more than an angled slot. A well fit slot should not bind whether it is angled toward the tuner or if it is perpendicular to the frets.
Some folks like to curve the slot, but that leads to a danger of a string buzz, like a sitar, between the nut and the tuner. Strings are stretched straight (for all practical purposes) between the nut and the bridge, and if they are to be firmly seated in the nut and bridge without buzzing they must bend. Curving the slot does not change that.

[sblock]

I like to cut nut slots so that they roughly bisect the angle of the string path from the front edge of the nut to the tuner post. That means the slot is angled downward toward the back edge of the nut and it is angled toward whichever side bisects the angle to the tuner post. Snake head or otherwise, most mandolin pegheads are similarly angled downward from the fingerboard plane, so strings must break over an angle at the nut and some of that angle is to the side with any "standard" tuners in any normal positions. When you think about it, a slot perpendicular to the fret has the potential to deflect the string from it's path to the tuner much more than an angled slot. A well fit slot should not bind whether it is angled toward the tuner or if it is perpendicular to the frets.
Some folks like to curve the slot, but that leads to a danger of a string buzz, like a sitar, between the nut and the tuner. Strings are stretched straight (for all practical purposes) between the nut and the bridge, and if they are to be firmly seated in the nut and bridge without buzzing they must bend. Curving the slot does not change that.

+1 to everything JH wrote! The "downward" bend associated with the peghead break itself (that is, angling away from the fretboard) is typically greater than any small "sideways" bend associated with going laterally over to a tuner. Once you realize that, and the fact that the string MUST bend at the nut, regardless (as JH pointed out), then you realize that you don't need a weirdly curved slot (both down and sideways) and you ought not worry too much about this. A good compromise is a straight nut slot that roughly bisects the angles involved.

On another point: Yes, the Gibson snakehead peghead design is a very good one, and highly functional, but the fancier design (with the scroll) found on their F4 and F5 models has almost the exactly same string break angles at the nut, both downward and sideways.