scale length determination/bridge position.

Discussion in 'Luthier's Corner' started by petie-b, Nov 21, 2005.

  1. petie-b


    Aug 24, 2005
    orlando, florida
    I have aquired a short scale bass and i am currently trying to make some good of an old wreck. but i have no idea who originally made it or the exact scale length. i dont have the original bridge so i bought an aftermarket one.
    Can i just put the bridge on in the same place as the original. My worry is that if i put it in the wrong place i wont be able to set up the intonation properly.

    Any help would be much appreciated.
  2. Rodent

    Rodent A Killer Pickup Lineā„¢ Commercial User

    Dec 20, 2004
    Upper Left Corner (Seattle)
    Player-Builder-Founder: Honey Badger Pickups & Regenerate Guitar Works
    To determine the scale of the neck that's attached, measure from the body side of the nut (or the top of the zero fret, if it's so equipped) to the top of the 12th fret and multiply by two. This should be what the neck scale is.

    15" x 2 = 30"

    Now measure from the body side of the nut (or the top of the zero fret, if it's so equipped) the distance of the neck scale length of the G-string side of the neck. This is roughly where the intonation saddle for this string will be.

    On your new bridge, measure the distance that an intonation saddle can adjust back/forth to aid in determining the next step.

    The E-string will intonate somewhat longer than the G-string did (unless you use a string where only the core rests on the intonation saddle - I have no example of this to measure, as I don't use this style of string.) On a 35" scale bass this is about 3/16" (I'm eyeballing it.) The location of the bridge will then be made such that it's perpendicular to the centerline of the neck, equally spaced on each side of this centerline, and at a distance that allows some extra room to intonate the G-string shorter than the scale length (maybe 1/8" at most) so long as it allows the E-string to have maximum intonation adjustment length longer.

    Hopefully when you place your new bridge in this location you'll also find a set of pre-drilled holes from the previous bridge installation. If not, you'll need to determine where the mounting holes should be and pre-drill pilot holes a diameter equal to the shank diameter (NOT the outer thread diameter!) of the mounting screws. Be sure to drill the holes deep enough - but not so deep you drill completely thru the body.

    If something here is not clear (I'm typing before I've had coffee this morning), drop a reply and I'll clear things up

    All the best,

  3. petie-b


    Aug 24, 2005
    orlando, florida
    That is pretty much the confirmation i needed to hear, ive been looking for info on this subject for a while now.

    many sites ive seen say that its best to measure the e-string for this method as it gives more accurate results.

    I assume you would dissagree with that.
  4. Hookus


    Oct 2, 2005
    Austin, TX
    The scale length is measured at the G string.

    Measuring this at the E will make the rest of your strings pretty much impossible to intonate.
  5. petie-b


    Aug 24, 2005
    orlando, florida
    Ok guys, thanks for the info.

    one other quick query. ive never had a short scale bass before and i was wondering if you need to use the short scale strings that are available or can regular scale strings be used
    i know it sounds like a very silly question but i have a set of spare regular strings already.