dual action truss rod installation

Discussion in 'Luthier's Corner' started by p_baker, Dec 16, 2017.

  1. p_baker

    p_baker Member

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    So guys, I searched the whole web but couldn't find an answer.
    With dual action truss rods: How far should the adjustment nut extend behind the nut. I'm unsure if I routed to far but I think, I could easily fill the channel partly from the heel side.
    IMG_0617.JPG
     
  2. pshupe

    pshupe Senior Member

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    Depends on the length of the rod and the neck. I generally line the centerline of the rod with the centerline of the neck, but can bias it either way depending on how that affects where the access is located. Those dual action rods with allen key adjustments are the ones I use because the access slot is the smallest resulting in less material taken away, which I assume is stronger. The function of the rod is to counteract bending of the neck, so I try and put the rod in the best position to do that job.

    Cheers Peter.
     
  3. cmjohnson

    cmjohnson Senior Member

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    Are you using a two rod unit, or a single rod PRS style dual action rod? (Works on the turnbuckle principle)
     
  4. ARandall

    ARandall Senior Member

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    The other point is that you should easily be able to access the adjustment.
    Yours looks like its under the nut at present.
     
  5. geoffstgermaine

    geoffstgermaine Senior Member

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    I generally have the end of the upper rectangular bar end just short of the nut and I continue the 1/4" channel further than yours and then put a short 1/4" filler piece which becomes part of what the nut sits on. I'll see if I can find at image....

    fullsizeoutput_f3e.jpeg

    There. You can see there's a short filler strip in the slot just left of the end of the headstock veneer. I use a bit of a different slot into the headstock as I ship these with hex keys that are quite long and have the t-handle so I don't remove extra material for the shorter L shaped hex keys to work.

    Here's how it looks with a rod in the channel:

    IMG_2119.JPG
     

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