Building a 24 frett frettboard for 6 stringer

Discussion in 'Hardware, Setup & Repair [BG]' started by Bruno Gomes, Jul 18, 2001.

  1. Bruno Gomes

    Bruno Gomes

    Jan 16, 2001
    I'm going to build my bass from scratch, so can anyone give a list of measurements for the frett spacing of a 24 frett frettboard for 6 string bass?
  2. Fret spacing is based on a formula that is scale dependent. The magic number used in positioning the frets is 17.817. So if your bass has a 34 inch scale you would take 34/17.817=1.91 inches. So the first fret would be 1.91 inches down from the nut or 32.09 inches up from the bridge saddle. The second fret would be 32.09/17.817=1.80 inches down from the first fret or 30.29 inches from the saddle. And so on until you run out of fretboard.
  3. There may be other considerations that would affect the fret spacing. The thickness of the fret and how high the action should be would affect where you would need to position the fret for correct intonation. I'm not sure how luthiers deal with this.

    - Dave
  4. This link is to a very neat fret spacing calculator that I've used myself. It's small, accurate, if you're into this kinda thing, something you shouldn't be without.

    Dave, at first glance, it may seem that some of the variables you've mentioned would have an effect on fret spacing but it just ain't so. Given a standard scale length, say 34" as in the Fender, the basic length of the scale is 34" (with adjustments made for for intonation) but the 12th fret (primary harmonic) is exactly 17" from the nut. That won't vary at all until you change the scale length. Fret height doesn't change spacing or intonation either since the string doesn't know (or care) how high the fret is. Besides, when you play, you don't actually press the string down all the way to the fretboard behind the fret. All you actually do is press hard enough to stop the string from vibrating. It actually takes only a bit more pressure to fret a note than it does to create a harmonic on an open string. String height CAN have an affect on intonation but it would have to be an extraordinarily high action to begin to hear the difference. But your observation isn't without merit. You've actually pointed out the problem with fretted instruments and their relation to the scales we are used to hearing in western music. In reality, our instruments aren't perfectly "in tune" no matter what we do to make'em that way. Of course this is a matter of small degrees and, over time, we have come to hear the fretted bass as being in tune. This is also a very technical subject and one that I'm not very well versed in. If you want a real long-hair discussion on this subject search the Bottom Line (a subscriber digest for bassists). I seem to recall that there are several threads that elaborate in great detail on this subject.
  5. BenF


    Mar 29, 2001
    Boston area
    Luthiers Mercantile International can cut fret slots and radius a fingerboard for you if you decide that it's too complex to do on your own.

    According to their catalog they can do a 6 string bass fretboard, 34 or 35 in. scale, 16 in. radius.
    Don't know what the cost would be, sorry.

    You have to download the catalog or call to get the details, they aren't on the site.

    Good luck!