Machine heel of neck? Saddle adjustment screws are nearly full in...

Discussion in 'Luthier's Corner' started by Jim C, Jun 12, 2020.

  1. Jim C

    Jim C I believe in the trilogy; Fender, Stingray, + G&L Supporting Member

    Nov 29, 2008
    Bethesda, MD
    I have a buddies bass on loan with a small issue. The set up is nearly identical to my Sandberg except which is perfect for me except for this one item.
    The neck relief is nearly flat and it plays great. The action needs to be raised as it is just too low for my finger style playing. The bridge adjustment screws are nearly fully turned in meaning there aren't many threads left. The obvious solution is to get longer screws at the bridge but I don't like the idea of increasing the break angle for the strings. I could machine a plate to go under the bridge but as I recall, G&L has a "foot" that presses into the end grain? The bridge shim wouldn't have to be very tall though; maybe .025". The neck could be shimmed but that seems like a bad fix since the angles are good. The real repair would be too machine .020" or so off the back of the heal to get the neck deeper into the body. I don't have easy access to the Bridgeport mill I once had and not sure how to clamp the thing without scratches. OTOH, I think it is amazing this bass left the factory like this and think that sanding the heal might be the best fix as it will never be perfect. Really poor workmanship on an otherwise nice instrument. Not sure how this could even happen if the parts are made by CNC equipment.
  2. charlie monroe

    charlie monroe Gold Supporting Member

    Feb 14, 2011
    Buffalo, NY
    You forgot to mention that you have buddy’s express permission to cut on his bass.
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  3. Beej


    Feb 10, 2007
    Vancouver Island
    Pics will definitely help. Assuming it's a G&L bridge, I can't see how you exhausted more than 1/4" of vertical height adjustment, but still need to go higher? If this is a stock instrument, something is wrong. :)
  4. SteveCS


    Nov 19, 2014
    Hampshire, UK
    Have you checked that it isn't simply a case of removing an over-enthusiastic shim?
    Jackcrow and Paulabass like this.
  5. Jim C

    Jim C I believe in the trilogy; Fender, Stingray, + G&L Supporting Member

    Nov 29, 2008
    Bethesda, MD
    Great idea and I did not checked this.
    Also forgot to mention that the nut is cut at about .020" which I think is OK.

    Turns out that there is just enough thread.
    I don't like the idea that the screw is so far down in the hole but it now plays perfectly!

    I'm going with factory QC but I suppose that's why they are adjustable as it would be impossible to hold real tolerances with mass produced instruments made from wood. At least that's what I'm telling myself.
    dkelley and mikewalker like this.
  6. Beej


    Feb 10, 2007
    Vancouver Island
    You should be able to get 1/2" of height off the bridge baseplate to the tops of the saddle grooves to accommodate super-high Jamerson-like action. What I can't picture is how you are still too low with this much height?
  7. FunkHead

    FunkHead Supporting Member

    Mar 10, 2007
    May I ask how many neck bolts there are?
  8. Jim C

    Jim C I believe in the trilogy; Fender, Stingray, + G&L Supporting Member

    Nov 29, 2008
    Bethesda, MD
    I'm no expert but I think the US JB2 had 6
    My JB2 Tribute has 6
  9. FunkHead

    FunkHead Supporting Member

    Mar 10, 2007
    Pm sent.
    Jim C likes this.
  10. Bruce Johnson

    Bruce Johnson Gold Supporting Member Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    Yes, I'd first check to see if there is an errant shim in the pocket. One other possibility is that the body has warped and developed a back bow. Not real common, but it happens.
    SteveCS and Matt Liebenau like this.
  11. JeezyMcNuggles

    JeezyMcNuggles Supporting Member

    Feb 23, 2018
    Santa Maria, CA
    I suck, but nobody really notices
    I would've just simply ripped a small piece of cardboard packaging from a hot wheels car, or pack of batteries, or any other trash for that matter, and stuck it in the front half of the neck pocket and called it good. But, whatever. You got it.
    dkelley likes this.
  12. Jim C

    Jim C I believe in the trilogy; Fender, Stingray, + G&L Supporting Member

    Nov 29, 2008
    Bethesda, MD
    Professionals have told me that this can cause a warp in the neck often times called a ski jump.
    It is not the angle of the neck to the strings that was off (IMO).
    It was the distance between the strings and the frets. This bass in particular has dimensions that require the screws in the saddles to be nearly screwed all the way in to get the action high enough (and it isn't that high) to play cleanly without fret noise with medium firm finger style playing. I haven't settled on the exact string height yet or I would have posted this dimension. The bass currently has XL nickels which are reasonably stiff so no unreasonable set up expectations with a super floppy string.
    seve545 likes this.
  13. klyph

    klyph Supporting Member

    Mar 28, 2009
    Cape Cod
    I swapped necks on two 5 string G&Ls, a ‘98 1505 and a ‘94 2500. The 1505 (ebony) neck on the 2500 body was my main player for many years. I had a similar problem and wound up machining and installing a brass shim underneath the bridge. Worked great, no problems. Mine was significantly thicker than 0.025” thick. I tried a “reverse” shim on the neck but the geometry wasn’t right and it looked like crap. Shimming the bridge is definitely an option. Mine plays like butter and is perfectly stable.

    The g string saddle had this problem on the 1505 with the original neck. I bought new 4-40 set screws for just that saddle.

    Another EDIT:
    The original neck on the 2500 had the “ski jump” problem. Maybe these are all related issues. They are just factory instruments, after all...

    last EDIT, I promise:
    I played the 1505 stock for many years and loved the neck, but longed for the dual-pickup sound, and found the cheap 2500 with a roached neck. My shim is closer to 0.090” (3/32) thick. Which sounds insane, but is really not that bad looking.
    Last edited: Jun 12, 2020
  14. Spidey2112


    Aug 3, 2016
    How does your buddy like playing it?
  15. Tim Skaggs

    Tim Skaggs

    Sep 28, 2002
    If there’s not a shim in the bridge end of the neck pocket, and you don’t want to put a shim in the nut end of the neck pocket, put a full coverage shim under the bridge. That’s a very harmless and very reversible mod, and a heck of a lot easier than milling 0.020” off the back of the neck heel, which is totally irreversible.

    The other option is a full coverage wedge shim in the neck pocket with the thick end toward the nut. No danger of ski jumping the neck with a full contact wedge shaped shim.
    Last edited: Jun 12, 2020
  16. klyph

    klyph Supporting Member

    Mar 28, 2009
    Cape Cod
    I made it slightly bigger than the footprint of the bridge, maybe you can see it. Worked like a charm, never a problem. I will post a better pic if I can get the bass out of storage... B953DB09-0B79-43F2-8052-195A97A06777.jpeg
    ctmullins and Jim C like this.
  17. Jim C

    Jim C I believe in the trilogy; Fender, Stingray, + G&L Supporting Member

    Nov 29, 2008
    Bethesda, MD
    He has a light touch and he is fine with it as it was. I play a little more aggressively. It's on a long term loan at the moment.

    I agree but I like my Sandberg as the neck, strings, and body look to be parallel to each other. There is very little relief in the neck and it plays like a dream. in other words, everything is pretty flat and the fretwork is awesome.
    I'm no expert but it seam that it should work with stiff strings on any bass assuming the above is done well. I'm complaining about tolerances that are not as perfect as I would like.
    Spidey2112 likes this.
  18. Bassamatic

    Bassamatic keepin' the beat since the 60's

    Just - 1) Remove any shim at the bottom of the pocket and b) Put one at the top of the pocket. Just a couple of slices cut from a business card is fine. I have gone through this many times, in both directions. You are not going to "ski jump" the neck over a couple of inches of hard maple.

    You don't even have to take the neck off to do this - just loosen the strings and screws, slide the shim in, re-tighten and re-adjust your bridge.
    donahue likes this.
  19. Tim Skaggs

    Tim Skaggs

    Sep 28, 2002
    They might look parallel, but they almost certainly are not, and if they are, machining off the back side of the neck heel, will lower the entire neck (nut & fingerboard) in relation to the top of the body. The fingerboard might remain parallel to the top of the body, but the strings will no longer be parallel to the fingerboard or the body, unless of course, you lower the bridge saddles, which will counteract what you are trying to achieve.

    There is a very logical reason luthiers tilt necks with shims rather than mill off the back side of the neck heel. Both actions will result in creating a greater angle between the strings and the fretboard, but one method is much more difficult, requires a mill, has a much greater possibility of error, and is irreversible. Tilting the neck up with a wedge shim allows different angles to be tried and is completely reversible.

    If you want to keep the fingerboard, strings, and top of the body completely parallel, be prepared to have a very buzzy bass (current problem) or a very high nut & bridge saddle height.
    Last edited: Jun 12, 2020
    IronSpatula likes this.
  20. 2F/2F

    2F/2F Supporting Member

    May 26, 2009
    Los Angeles, CA
    You are worrying about a bunch of stuff that doesn't matter, and it's leading you to consider a completely unnecessary permanent mod to a bass that isn't even yours. Just stop right now and step away before you think yourself into a hole.

    First: Pix. Lets see how high these bridge saddles actually are.

    Next: Measurements. Lets see how much thread actually remains on the adjusment screws – not an eyeballed estimation.

    You say the screws are almost out of threads. Almost isn't completely. See what you can do with simple saddle height adjustments. If you run into a problem, only then think about trying other methods.

    There's no drawback to this. There's not any reason not to like increasing the break angle. It won't affect anything in a bad way. It's not like you're going to a string-through-esque break angle. You're moving your saddles up a small amount. I run strings that aren't supposed to be strung through-body, through body. Zero problems. Raising saddles by any available amount on the adjustment screws will do nothing bad.

    If the saddles truly run out of thread, i.e. fall out the bottom, then simply buy longer screws. There's no reason not to.

    That said, a cheater fix that is completely reversible (and would not require any ciperhin' to get the right screws) would be to put a piece of sheet metal all the way across the under-saddle area of the bridge. If Roy Buchanan can use a coin and be celebrated for having some of the best guitar tone of all time, with a front-and-center instrument, then you can use a piece of cheap shim stock with an instrument that gets its finest nuances obscured in the mix (or...maybe you could even use some coins).

    The higher class version of that fix is a shim under the bridge – G&L's little metal thingy that goes into the body be damned. I dare you anyone to hear a difference in a real work mix by pulling that thing out of the body by even 1/4", let alone a few tens of thousands of an inch. But hell; if it gives you the warm fuzzies, drop a shim down into that little cavity as well.

    Shims are a standard and traditional adjustment on instruments with screw-on necks. Most old Fenders came out of the factory with them – "most" as in "almost all" – and many still do. So many that Micro-Tilt was invented, and carried forward to Music Man and G&L (and, sadly, deleted).

    No, that would be a highly unintelligent repair (and even if you were going to do it, taking the wood off the body – not the neck – is the more sensible way to do it). You have several non destructive options available that will work fine. You're just obsessing over theoretical details that don't actually matter. Knock it off and do the simple and effective fixes that will WORK and affect NOTHING except to improve the playability of the bass.

    P.S. Nut slots at .020" off the board are not anywhere close to OK, unless perhaps it's a fretless...and I thought I read you making mention of frets. G&Ls use medium jumbo frets, which are over .050" tall to start.
    Last edited: Jun 12, 2020
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