Setup or improvement on fretless board?

Discussion in 'Hardware, Setup & Repair [BG]' started by StuartV, Mar 11, 2014.


  1. StuartV

    StuartV Out of GAS!! Supporting Member

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    Jul 27, 2006
    Location:
    Bristow, VA
    I have a fretless J I put together a while back. I worked on it over the weekend to lower the action. I was just eyeballing things - no proper tools to measure with. But, the neck relief was minimal - it looks just like a couple of my other basses that have nice low action.

    But, when I lower the saddles to as low as I can and still play it, the action isn't as low as I thought it should be able to take. Any lower and when I fret just about anywhere it seems to buzz all around frets 18 - 20. And I even noticed some signs of wear on the board around the neck heel.

    So, my question is, is this an indication that I need to plane/level the board? Is this just how it is with fretless? The action is just about as low as my best fretted basses, so maybe I'm expecting too much? Should I shim the neck to change the angle just a little bit (raising the headstock end slightly)? Should I take some relief out to get it even more straight?

    The board is ebony with lines. It's an Allparts neck. Is it safe to do some sanding on the whole thing? In particular to get rid of the signs of wear down around the heel end of the board?

    Thanks for any guidance!
  2. Scoops

    Scoops Vagabond at large Supporting Member

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    Oct 22, 2013
    Location:
    Sugar Creek, Wisconsin
    Based on the info given, I'd start playing with the truss rod to see what's going on there.

    How's the nut? is it cut too low? Too 420?

    Could be your FB just needs some sanding. That's pretty easy to fix. Just really need 2 tools minimally, a long straight edge, and a sanding block with a radius in it.

    Me personally, i don't like shims, but sometime you can't avoid them, so I'd save that for last.

    -Scps
  3. JustForSport

    JustForSport

    Joined:
    Nov 17, 2011
    A little flatter, then raise the saddles just enough, IMO.
  4. bassbenj

    bassbenj

    Joined:
    Aug 11, 2009
    I agree. And get the sanding block (matches radius of fingerboard) and long stright edge. Beware of wavey necks as those high spots are the usual cause of the buzz problem.

    But let me also say that super low action isn't the holy grail on a fretless. The amount and the sound of the "mwah" you get depends on the angle the strings make with the neck. So with higher strings or more relief that bass will tend to sound more like a fretted with less Mwah. On the other hand because no neck is perfectly straight in spite of efforts to do so, as you try for lower and lower action (and more and more mwah) You'll eventually reach a point where the strings will start to touch any high spot in the neck and you'll get buzz

    I had a fretless that had a buzz at pretty high action. So I just used the sanding block and the straight edge to get the neck as flat as possbile with not string tension and truss rod adjusted for flat (which was no tension in this casei if I recall correctly) Then put strings back on and adjusted for just the tinyest relief. Bass plays just great now and sounds fretless cool too.

    Luthiers have special jigs to put a neck under tension when you sand it that helps give you the flatest job under tension. But the no string tension flat sand and then add strings and adjust truss rod method worked pretty well for me, but if you try to get really low action, you can see that there still are a couple of high spots that buzz. But the action after the flatening was MUCH lower than it was before.
  5. StuartV

    StuartV Out of GAS!! Supporting Member

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    Well, I'm not having a problem with buzzing on open strings, so I don't think the nut is too low. I don't know if it's too high. How would the nut height affect buzzing when I'm fretting notes?
  6. Manton Customs

    Manton Customs UK Luthier Supporting Member

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    Sounds like you just need a bit less relief to be honest. But to find out if the board needs leveling and put your mind at rest just check it with a straightedge :). To do this you'll first need to adjust the truss rod until you have no relief and the neck is flat. Then use a long straight edge across the different string paths (strings off) and see if there is anywhere that the straightedge rocks or you can see light under. You don't need to play around with the neck angle if your bridge has enough adjustment to still go lower.
  7. Scoops

    Scoops Vagabond at large Supporting Member

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    Oct 22, 2013
    Location:
    Sugar Creek, Wisconsin
    There's a balancing point with the nut height, truss rod tension, bridge height, and neck straightness all go to define your action. I have one bass where I probably have the nut cut too low, and if I have a certain tension on the truss rod, I'll get a buzzing of 1 of the strings in one isolated section of the neck. You had indicated that your action wasn't the best, so I just mentioned that the nut is part of the equation.

    Sorry I didn't give greater detail on using the straightedge, but others have, so that's a good thing.

    Cheers
  8. StuartV

    StuartV Out of GAS!! Supporting Member

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    Bristow, VA
    I think I'm starting to get it. ;)

    I will take some relief out first, and see how it does. I would have tried that when I was working on it on Sunday, but the neck is a heel adjust that requires unbolting the neck. Being the PITA that that is, I just settled for the improvement I got from lowering the saddles, for the time being.

    Thanks again for the help!
  9. Lownote38

    Lownote38

    Joined:
    Aug 8, 2013
    Location:
    Nashville, TN
    Give the trussrod a 1/4 turn clockwise (to take some relief out) and see what that does. A heel adjustment is pretty easy if it's a screwdriver type (rather than hex key). The right sized flathead screwdriver can get in the exposed slot and you can turn it without taking the neck off. A narrow flathead should do the trick.
  10. walterw

    walterw Supportive Fender Gold Supporting Member

    Joined:
    Feb 20, 2009
    how low is the nut?

    that's where all too many fretless setups go wrong, with a nut that's still slotted like there were frets on the bass.

    if the slots are more than like a sheet of paper thickness above the wood, then it's too high, and needs the slots brought down.

    it'll be a night and day improvement, even if the saddles are set higher.
  11. Bruce Johnson

    Bruce Johnson Supporting Member

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    Fillmore, CA
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    From Stuart's description, it sure sounds like this neck has the classic "ski jump" condition, which is so common on older Fender necks. I call it the 12th Fret Kink. Regardless of what you do with the truss rod, you'll still have that ramp out at the end. Remember that the truss rod really only changes the curvature of the neck from the nut to the 12th. It has almost no effect from the 12th to the heel.

    So, if you can adjust the truss rod and bring the area from the nut to the 12th relatively flat, and you still see a big ramp from the 12th to the 20th, there's your problem. The fingerboard needs to be re-leveled to get rid of the ramp. You can't adjust it out.

    If it's an older Fender neck, I'd be surprised to see that it didn't have the ramp. They almost all kink there to some degree over the years. When you start lowering the action, particularly on a fretless, the problem shows up.
  12. StuartV

    StuartV Out of GAS!! Supporting Member

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    Bruce, it's an Allparts neck that I bought used, off another TB'er.

    Walter and lownote, thanks for those tips. I had a jam session last night, so no time to futz with the setup on the fretless. But, when I do get to work on it, I will:

    - adjust the truss rod to take some relief out
    - check the nut slot height
    - check the board for flatness/ski jump

    The action is pretty close to what I want already. From what you all have said, I have some optimism that just taking some relief out will get it to where I want it. But, if not, I will order up the right sanding block and see about leveling it out some. And/or order some nut slot files and attempt to lower the slots. These are all things on my list to learn anyway, so this is a good opportunity.
  13. StuartV

    StuartV Out of GAS!! Supporting Member

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    Jul 27, 2006
    Location:
    Bristow, VA
    Thanks again for all the input, folks. I worked on it over the weekend.

    All I did was pop the neck off and tighten up the truss rod 1/4 turn. The board is now dang near flat. And the action is super nice now, with a significant enhancement in the "mwah" department!

    I did check the nut, and the slots are down almost to the board itself, as walterw suggested they should be.

    Now I'm just looking forward to my next opportunity to play it with somebody!

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