Nut slot angle?

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by aortizjr, Jan 30, 2006.


  1. aortizjr

    aortizjr Member

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    I have all the tools ready and am getting ready to cut a new graphite nut for one of my 7-strings.

    Quick question, at what angle should the slots be cut? It is an angled headstock guitar.

    Should they be flat, or parallel to the fretboard. Or angled at the same angle as the string as it hits the headstock?
     
  2. John Phillips

    John Phillips Member

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    Between the two angles, but closer to the headstock angle than the fingerboard. You want to make the point of vibration accurately at the front edge of the nut, and avoid the string snagging at the back edge.
     
  3. LaXu

    LaXu Member

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    They should gradually angle so that at the fretboard side the slots are the angled like the fretboard and going towards the headstock the slots angle to the angle of the headstock. Kind of a smooth slope type thing. The slots should also widen on the headstock side so that the string can be angled to the tuners and won't snag to the nut edges.
     
  4. fullerplast

    fullerplast Senior Member

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    I disagree with this. I think John has it right. You want close to a knife edge contact at the front end and you want the angle at least greater than or equal to the headstock angle so that there is a single contact point for the string; that being the front edge. You'll have intonation, friction, and possible buzzing problems if the string contacts along the full slot. Use the string angle as a guide....if the string touches the back edge of the slot, it's not a sufficient cut angle for the slot.

    I do agree that you can widen the slots towards the headstock side if needed, as in a Gibson.
     
  5. Liquid Quarter

    Liquid Quarter Member

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    I have to agree with John and FP regarding the nut slot/string angle. Anyway, look at this tutorial on Nuts :D



    http://www.stewmac.com/nuts



    LQ
     
  6. Clorenzo

    Clorenzo Member

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    I don't think that's what John said, I think he meant like this: http://www.frets.com/FRETSPages/Luthier/Technique/Setup/NewNut/newnut3.html

    Which is the way I always do it and never had any intonation, friction or buzzing problems.
     
  7. John Phillips

    John Phillips Member

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    That's exactly it - although he says "halfway", and I would say more like 90% of the way to the headstock angle. But I think the string should rest on the full width of the nut, if only lightly - if all the pressure is taken at the front face, the groove will wear deeper very fast and it may even cause snagging, especially on the wound strings. These are all fairly minor variations though - the important thing is that the groove should be basically at the headstock angle, not parallel to the fingerboard.

    I also totally agree about the grooves needing to be smoothly round-bottomed and larger than the string diameter - if you do it really well, they can actually be quite a lot bigger and work perfectly, because a round string in a round groove is still self-centering no matter what the two radii. This to me makes it a bit of a myth that the grooves need to be fitted to the string gauge - they will work equally well with any of normal gauges if they're big enough for the largest. I've even set up a couple of guitars as semi-baritones (one with 13-65 gauge, and one with 15-75 :eek::)) and had no problems refitting 10s afterwards... with grooves up to 50% wider than the strings.

    I also like the slots a little deeper than often recommended - I like to have the whole string diameter below the top of the nut if possible... at least for the hamfisted way I play ;). It doesn't make any difference to the friction or tone since the nut can't be touching the string above its halfway point no matter how tall it is, but it does stop the strings jumping out of the grooves, especially with low headstock angles (the G on Fenders with only one string tree is especially bad).

    Just my opinion and the way I do it - there's more than one variation that works.
     
  8. fullerplast

    fullerplast Senior Member

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    I don't use the headstock angle as a guide, I use the actual string angle. It changes for each string, due to the difference in distance from the nut, the number of wraps used on the post, and whether there is a string tree or not. In order to get maximum pressure at the front edge, and to ensure that that is the actual point of contact, the slot angle needs to be slightly greater than the string angle. I've done it this way for years and have yet to see any significant premature wear on bone nuts. My #1 has seen six years of heavy use on the same nut and it's still quite fine. YMMV, of course!:)

    [​IMG]
     
  9. John Phillips

    John Phillips Member

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    I was really talking about angled headstocks... and the way you've done that, the angles are all about the same anyway :). (That's pretty much how I string Fender-styles too, BTW.)

    Just a question - how low do you cut the nut? Preferences vary here too, and I like it really low - only just above fret height... I go by the gap under the string when fretting at the third fret, and aim for less than 1/4 of the string diameter on any string, down to maybe 1/10th on the low strings. You might have to be careful about front-edge wear when it's that low.

    There's definitely more than one 'right' way if you know what you're trying to achieve though.
     
  10. fullerplast

    fullerplast Senior Member

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    Hi John- I figured you were talking about angled headstocks, which is really another reason I used the Fender as an example of why to use string angle.:)

    I like the nut slots very low, and what I actually do is use a "half pencil" to mark a line on the nut that is exactly the height of the first fret. I use that as the absolute lowest I want to go.

    When you think about it, the nut slot would ideally be that height, which is some luthiers use zero frets. It's also the same as if you put a capo....the fret becomes your new "nut" and that height is exactly the fret height by definition.

    I reality, I give a tiny bit of extra clearance, probably about the same as your measurements. For either Fender or Gibson nuts, the low E string slot is always a more extreme angle than the D string, just due to the proximity to the nut, and that's what I was trying to emphasize. I always like to see a tiny gap at the trailing edge of the nut for each string.

    There are certainly different approaches and philosophies about this, but I find for myself that if I don't get the slots low enough, the notes on the first three frets or so are a bit sharp and it drives me crazy on open chords....:)
     

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