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Fretboard Radius

Discussion in 'Hardware, Setup & Repair [BG]' started by bassist4ever, Jan 8, 2003.


  1. does anybody know what the radius of the essex jazzes fretboards are? since i made mine fretless i noticed that there are slight dipps where the frets were causing it to buzz horrendusly
     
  2. pkr2

    pkr2

    Apr 28, 2000
    coastal N.C.
    I really don't mean to oversimplify, but why don't you just measure the radius?

    If your not sure how to do that, I'm sure someone can explain how.


    Pkr2
     
  3. uhh nobody ever taught me how to measure the radius of a fretboard...... now a circle... thats easy :)
     
  4. neptoon

    neptoon

    Jul 25, 2000
    summerville, sc
    i think you would have to use a radius guage. i think if you were to take the curvature of the fretboard and extend it into the circle that the curve is a segment of, that's where the measurement would come from. without some sort of tool, i don't think you could measure it accurately.
     
  5. You could probably PM Kurt and ask him if you're too lazy to measure it yourself.
     
  6. pkr2

    pkr2

    Apr 28, 2000
    coastal N.C.
    Get or makeshift a compass type divider. Start by scribing a 12" circle on a piece of card board.

    Cut a 3" segment from the circle being careful to cut close to the line.

    You then use the segment as a radius guage.

    It wont fit the first time or two but only two or three adjustments of the circle size will make the right template.

    The size of the circle is the radius of the board IE. a 12" circle = a radius of 12".

    Is that as clear as muddy water? :)
     
  7. I just measured one of the Essex J necks I've got laying around here and it does indeed work out to a 12" fretboard radius. Good thing since that's what Jazzes have in the first place.

    My friend Pkr2 misspoke about the actual relationship between a circle of a given diameter and a fretboard radius. In this case a radius is just that - a line from the center of a circle to it's perimeter. Double the radius and you have the diameter of a circle. To achieve a 12" radius, you must scribe a 24" circle. That's what I did to get the measurement I listed above.
     
  8. pkr2

    pkr2

    Apr 28, 2000
    coastal N.C.
    You are right, Hambone.

    Fingers are going faster than my brain.

    TNX

    Pkr2
     
  9. so its 12" all the way?
     
  10. neptoon

    neptoon

    Jul 25, 2000
    summerville, sc
    i'm thinking that on most radiused necks that the radius gets smaller as you go higher on the neck. not sure though....maybe you measure at the 12th fret?
     
  11. On the same topic, what is the point of a fretboard radius?
     
  12. In most production basses, the radius is the same all the way up the neck. As the neck narrows towards the neck, the radius appears to flatten out but it actually doesn't. It's just that a smaller length arc looks flatter than a longer one.

    The purpose of fretboard arc is to assist with string bending. Arc'ed fretboards provide something to push the string against without having to use all finger strength to keep it against the fretboard. A flatter fretboard is a little bit harder to bend strings on. It all boils down to preference. I've got a bass that has something like a 16" radius - much flatter than my jazzes. But I've grown accustomed to the entire instrument as a whole and don't have any problems swapping up.
     
  13. neptoon

    neptoon

    Jul 25, 2000
    summerville, sc

    that makes sense...
     
  14. marc40a

    marc40a

    Mar 20, 2002
    Boston MA
    I just measured one of the Essex J necks I've got laying around here and it does indeed work out to a 12" fretboard radius. Good thing since that's what Jazzes have in the first place.


    Actually, Fender uses two different radii. A 'vintage' 7.25" and a modern 9.5".

    For the most part, pre '95 basses and the reissue series have the 7.25". Current models sport the 9.5".
     
  15. It always helps to have backup in these matters :)

    I just checked my MIJITSO 62 reissue and it does indeed have a 7.25" radius. I had always figgered they had a 12". I don't know where I first got that in my head. Thanx for the correction Marc
     
  16. jani_bjorklund

    jani_bjorklund

    May 22, 2002
    Finland
    The original fretboard radius on Fender instruments was(still is on vintage reissue models) 7 1/4".
    Because of the problems ("note out") Fender started offering 9 " and 12 " radius on their newer instruments.
    I would think most modern Jazz copys have 12 "radius.
     
  17. jani_bjorklund

    jani_bjorklund

    May 22, 2002
    Finland
    On guitars with compound radius necks(highend and custom handcrafted guitars)that is exactly the case. The radius gets smaller towards the nut, typically 10" at the nut and 16" at the end of the fingerboard. There are two ways of manufacturing the neck radius. The cylider shaped, even milled radius through out the neck and the compound, cone shaped that flattens out up the neck.
    The issue of the compund radius vs. the cylinder radius isn't that important on basses but is more important on guitars, especially when bending strings because of the "note out"phenomen on cylinder shaped necks. You can understand this if you imagine a straightedge on a cylinder-shaped fretboard. The only way a straightedge kan be in full contact with the surface on a cylinder is when it's paralel to the center. As soon as you slant the straightedge to the centerline(out of paralel)it looses contact from end to end and rocks on the "hill" in the center.
    So all in all many high end basses do have a smaller radius at the nut, as you sugessted, if they have a compound fretboard.
     
  18. marc40a

    marc40a

    Mar 20, 2002
    Boston MA
    Because of the problems ("note out") Fender started offering 9 " and 12 " radius on their newer instruments.
    I would think most modern Jazz copys have 12 "radius <<


    At the risk of sounding like a broken record, The radii that Fender produce are 7.25" and 9.5"

    No 9"
    No 12"

    'Modern jazz copies' are a different story altogether.