Nut Height..........(Slot Depth.....)

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by gainiac, Oct 14, 2006.

  1. gainiac

    gainiac Senior Member

    Messages:
    5,147
    Joined:
    Sep 14, 2004
    Location:
    Da Bronx
    Hey folks,

    I'd file this under "teething pain" for a new axe.

    I put together a Franken-Tele recently, I've got it set-up rather well BUT I'm having tuning issues with voicings in the lower registers, especially open (zero) position chords.

    I can tune the axe up just fine and dandy but, for instance lets use an E5, when I fret the B and E on the second fret of the A & D string I get beating.

    I really think that the strings are too high off the fretboard down by the nut and the extra "travel" that happens when pressing the strings down against the frets puts things out of tune down there.

    Typical?
     
  2. KeithC

    KeithC Silver Supporting Member

    Messages:
    5,313
    Joined:
    Dec 5, 2005
    sounds like the problem.
    I have had to lower the slots in pretty much all my Strats.
    I go as low as I can go without open string buzz.
    If you have the relief good and the overall string height at the bridge good then I would work on SLOWLY lowering the culprit nut slots.
    Stick a capo between the 2 and 3 frets and try to get the strings just barely clearing the first fret is what I do.
     
  3. Dana Olsen

    Dana Olsen Gold Supporting Member

    Messages:
    7,652
    Joined:
    Oct 2, 2002
    Location:
    Santa Barbara, Marin, Chico, CA
    Hey Gainiac -

    Try this method:

    First, MAKE SURE the truss rod is correcty adjusted! Then ...

    Fret the low "E" at the 3rd fret - a "G". Then press the string down between the 3rd fret and the nut - sorta tap down on the string - to gauge the clearance between the top of the 1st fret and the bottom of the string.

    The string should barely clear the first fret by like less than 1/64" (the thickness of a business card is max clearance for an electric guitar). If it clears by more than that, you need to cut the nut lots lower. Leave a tiny bit more clearance for the low strings.

    Repeat for all strings. It's better to err on the cautious side; you can aways cut 'em lower later. Lower the nut slot slowly - MAKE SURE you hold the nut file dead level when you file and MAKE SURE you bisect the angle between the plane of the fretboard and the plane of the headstock as you file. You want the nut slot to be dead level from the front of the nut to the back so the string makes maximum contact and so it comes off the front of the nut cleanly.

    I recommend getting your truss rod pretty close to straight - very little relief. If this is not possible or optimum on your guitar, that's OK, but make sure you adjust the truss rod first, otherwise if there's too much relief you can set yoursef up to cut the nut slots too low, and then you have to make a new nut and start over.

    Good Luck, Dana O.
     
  4. gainiac

    gainiac Senior Member

    Messages:
    5,147
    Joined:
    Sep 14, 2004
    Location:
    Da Bronx
    Thanks all for confirming my suspicion!


    I'm not going to do it myself, I'm bringing it back to the fellow whom I paid to assemble said axe to adjust it.

    It's a fat 1 11/16th's (at the nut), 25.5. big C with 6150's. 15" radius. The neck is straight as an arrow.
     
  5. Lucidology

    Lucidology Member

    Messages:
    25,861
    Joined:
    Aug 14, 2006
    Location:
    Monterey, CA
    Great info ...
    Thank you Dana
     
  6. JeffreyJones

    JeffreyJones Member

    Messages:
    50
    Joined:
    Nov 6, 2007
    Good for you. That's the nutwidth I prefer, although lately, I've been moving toward just going with the full 1.75" at the nut for my personal instruments. I've got tiny hands, but have difficulty playing cleanly in the first position on a 1 5/8" nutwidth.

    Some people prefer a smidgeon of neck relief, but if you prefer it straight, that's cool. All of Dana's advice is spot on.
     
  7. David Collins

    David Collins Member

    Messages:
    2,253
    Joined:
    Feb 10, 2007
    Location:
    Ann Arbor, MI
    Good advice - I would just add that I'd say way way way less than 1/64"

    1/64" is about .015". I view even .004"-.005" as way too high for an electric guitar. I would say height of the slot above the fret should be in the .0005" to .0015" range for the high e, and .001" to .003" for the low e, depending on playing style. Unfortunately there's no good method for measuring this in real numbers that's widely available (feeler gauges are worthless here in my opinion), so you have to rely on the skills of your tech. I actually made a few tools capable of accurately measuring this a while back, simply to quantify the measurement for the purpose of teaching, but have never seen anything similar in other shops.

    In the thousands of guitars I've worked on, I think I've seen a few dozen that have come from a factory with what I would consider proper nut height, a few from PRS and Collings mainly. Any guitar you buy, if it's not had the nut cut by a good tech previously, it needs it. I view pretty much all factory instruments as "some final assembly required", nut height usually being a main issue.
     
  8. Mike9

    Mike9 Supporting Member

    Messages:
    10,423
    Joined:
    Sep 26, 2006
    Location:
    Ghent, NY
    David is right on - Also when I cut, or tweak a nut I file the top of the nut so the lower strings sit half way into their slots and the higher strings are at, or just below the top of the nut. I also polish the slots and I get better trem action this way and always lube the nut slots - trem, or not.
     
  9. John Phillips

    John Phillips Member

    Messages:
    13,080
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    It's almost unnecessary to say so, but I completely agree with Dana and David. Almost every guitar I've ever worked on with a factory set-up has the nut too high.

    This is largely responsible for the idea that you need compensated nuts or tuning offsets for perfect intonation, IMO - since if the nut is too high, the strings play sharp over the first two or three frets. You do need a very small equal compensation of the overall nut position due to the physics of the way a constrained string vibrates, as Hamer, PRS, Taylor and other have done for years, but individual compensation should be unnecessary if the nut is cut properly.

    The way I do it is very simple - fret each string at the third fret, and look at the gap under the string at the first. It should be less than 1/4 of the string diameter, and possibly as small as 1/10th on the heavier strings, ie between about .001" and .004" from high to low across the fingerboard, but I never measure it, just go by eye and feel.
     
  10. Phil Harmoneeek

    Phil Harmoneeek Member

    Messages:
    403
    Joined:
    Feb 11, 2005
    Location:
    Close to T.O.
    How do you guys feel about Super glue to build up a slot that was cut a little to low. I have done this with success (I'm not a tech & just work on my own guitars), by using a tiny pin to take a tiny drop & apply it in the bottom of the slot than after a day, give it a little file adjustment & away I go. I feel I've got a pretty/really good ear & on the open string, I can't seem to hear any difference (& fretted ones shouldn't matter, right?).

    Thanks Randall
     
  11. kurtsstuff

    kurtsstuff Member

    Messages:
    2,354
    Joined:
    Oct 3, 2006
    Location:
    Lincoln City,Oregon
    Seems every Les Paul I've ever owned has needed the nut's tweaked
     
  12. Dana Olsen

    Dana Olsen Gold Supporting Member

    Messages:
    7,652
    Joined:
    Oct 2, 2002
    Location:
    Santa Barbara, Marin, Chico, CA
    Thanks John and David and Mike9 for the input. I used the 1/64" figure mistakenly - it should in fact, as you both point out, be much lower than that.

    A well cut nut truly solves most intonation problems, in my experience. Doing the job correctly is a real art.

    Thanks, Dana O.
     

Share This Page