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neck screws at a 45˙ angle ?

Discussion in 'Luthier's Corner' started by PeaveyPlayer, Nov 5, 2017.

  1. PeaveyPlayer

    PeaveyPlayer Supporting Member

    Jul 15, 2014
    Winnipeg, Manitoba

    after watching this video towards the end He was saying he puts 2 screws at a 45 degree angle like the billy sheehan attitude bass , has any other Luthier done this as well with positive outcomes?
  2. Means2nEnd

    Means2nEnd Supporting Member

    Not something I would do or think it would make much of a difference.
  3. b3e


    Sep 5, 2017
    Warsaw, Poland
    I'm actually planning on doing this in my build. I think there are two possible changes that it can bring:

    1. Theoretically it should pull the neck more into the corner of the neck pocket. I've noticed servicing my guitars and guitars for friends, that you can fix some sustain issues by loosing the neck screws a bit on a stringed up instrument and re-tightening them. A lot of times the neck jumps into the pocket tighter with an audible click and there is noticeable improvement in sustain. The question for a bass guitar is of course - do you need that sustain, or do you need the sound to pop?

    2. More reliability (at least in my construction) to have 5 screws than just 3 by such a joint.

    One thing that is different about the Yamaha is that it the neck is more recessed into the body, than on other bolt-ons. You probably have to account for that too in the whole equasion
  4. Arie X

    Arie X

    Oct 19, 2015
    getting a neck seated tightly in the pocket is the optimal condition of course. the majority of bolts that i've worked on when taken apart reveal lumps of paint, lumps of sawdust in said paint, caked-on buffing compound, crappy pocket work, chips of body wood pushing down into the neck pocket from the mounting holes in the tenon, and "foreign objects" used as shims. often on these things slipping a feeler gage into the joint tells all -and a feeler gage shouldn't fit in any neck joint. after i scrape and clean all of the crap out of the pocket and square everything up and re-assemble it there is a (imo) noticeable improvement in sustain, feel, and energy transfer to the bridge.

    have i used the method in the op? no. i generally prefer neck through construction but i have done retrofits of existing necks into existing pockets though in the standard fashion. were i to make a new bolt on neck instrument i'd likely tilt all of the screws 15 degrees or so from vertical to pull into the pocket and use threaded inserts in the neck tenon. seems like a more elegant solution imo.
    Last edited: Nov 6, 2017
  5. Beej


    Feb 10, 2007
    Victoria, BC
    No offense all, but I'm calling snake oil on this one. :D Yes, these extra screws seat your neck in the pocket, but so does just tightening the neck mounting screws. The tension of the strings themselves will also seat the neck in the pocket just as effectively as adding these extra screws. If you really were worried about the neck pulling out, then similar screws set in from the neck side of the pocket would logically be better to resolve that issue - the heel does not permit the neck to leverage out of the pocket, its the neck side area that would permit that with no screws there.

    I don't know for certain, but I'd suspect that on sheehan's bass, because of the cut away section on the back of the neck pocket, that in addition to making the pocket a little deeper, Yamaha added those extra screws as reinforcement to an already pretty shallow pocket... :)
    nolezmaj and reverendrally like this.
  6. rwkeating


    Oct 1, 2014
    I've read (here and in other forums) that it is possible to make the neck/body joint on a bolt on too tight. Is that not true? I thought the idea was to have the smallest amount of space for expansion differences since most often a bolt on neck is a different type of wood than the body.

    Edit: my comments aren't about the angled screws but about filling in the sides with wood and making such a tight fit you have to press the neck into the slot (as seen on the video.)
  7. I've seen many older bolt on instruments with cracks in the finish at either corner of the neck pocket, and a very tight neck joint. I presume(along with others on the internet), that expansion and contraction of the woods due to temperature change caused those cracks over time.

  8. I've used screws at an angle to get a good set in the neck pocket. 45deg? Total overkill. 5-10deg will do it perfectly adequately.


    You have to look pretty close to see any angle here, yet it worked perfectly.
  9. Frederiek


    Aug 8, 2016
    I think it is nonsense. I can imagine that slightly angled screws would be a good idea, but two at 45 and the rest straight... nahh. You don't need any pressure between those surfaces, just a proper connection.
  10. Picton


    Aug 16, 2017
    Reading, MA
    B-b-but guys! It “improves tone!”

    Never underestimate the power of the placebo effect.
    pilotjones likes this.
  11. Gilmourisgod


    Jun 23, 2014
    Cape Cod MA
    I think just using threaded metal inserts for machine screws instead of traditional wood screws is improvement enough. A tiny gap side to side doesn't seem to make any difference as long as the neck heel is tight to the pocket bottom. That kind of pocket screw setup is standard now for casework construction, where you are butting 3/4" thick material edge to edge, so it has to be screwed at a shallow angle, but I can't see any big advantage for bass construction. I briefly owned a weird Japanese Hofner clone that had a strange set neck design featuring a bolt that came into the neck pup pocket to pull it in tight to the body. It worked, but I've never seen it done that way since. I think they just wanted to avoid having to cut a really tight fitting tenon and pocket like a real Hofner.
    scourgeofgod and Zooberwerx like this.
  12. Frederiek


    Aug 8, 2016
    I thought long and hard about the threaded inserts vs normal wood screws idea and I came to the conclusion that it's over-engineering. Wood screws provide a perfectly tight and strong connection. A proper connection between surfaces is plenty - no need to overtighten them any more that you would need the threaded inserts. Only if there's a risk of stripping the holes, which wouldn't normally occur I'd guess unless you need to take off the neck often, and if so is an easy fix. Plus fitting and aligning the inserts can be a real b*tch :D
  13. Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    These would be my choices. Once the bass is tuned to pitch, slightly loosen the neck bolts and allow the neck to butt-up firmly against the pocket bottom then re-tighten.

  14. Frederiek


    Aug 8, 2016
    Does that trick work with threaded inserts? If you slightly loosen the neck bolts, the neck will be pulled a bit tighter into the pocket and a wood screw in a pre-drilled hole will allow to adjust to that difference. A metal bolt in a threaded insert however will not, as there is no room at all to compensate. In the worst occasion you would ruin the thread.
    scourgeofgod likes this.
  15. RSBBass


    Jun 11, 2011
    I think the most important aspect is a proper neck to pocket fit. If you have that, any of the traditional ways will work fine for attaching the neck.
  16. Gilmourisgod


    Jun 23, 2014
    Cape Cod MA
    My Steinberger XP-2 has a bolt on carbon fiber neck, they used knurled and threaded brass inserts cast right into the neck mold, solid as hell. They lasted 30 years without incident, until I stupidly over tightened one and loosened the insert. Talk about a PITA! I had to make a little jig to hold the insert in alignment while the epoxy repair dried. I can’t see setting them into wood would be any harder, though rock maple would require some wood threads cut.
  17. Bruce Johnson

    Bruce Johnson Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    I can tell you from extensive testing and experience that how the neck/body joint is fitted and clamped together can significantly improve or degrade the overall sound. It particularly relates to low-end clarity vs low-end mush. The neck/body joint is one of the major factors in why two "identical" Fenders will sound different.

    What's important is getting a good surface-to-surface fit on the bottom and heel end, and providing a lot of clamping force. The sides of the neck pocket should be a sliding fit or even a slight gap, to allow for shrinkage of the body. The traditional four wood screws into maple is adequate, if the surfaces fit well and the screws are tight. If not, the bass will get mushy.

    Adding additional clamping force, either from extra wood screws or machine screws threading into metal, will add more clarity and some low-end sustain. I've tried pretty much all the combinations out there, on necks for myself and clients. And I've done side-by-side testing on otherwise identical instruments.

    Back in the '90's I used steel T-nuts and machine screws on my own basses. The T-nuts were set into the top of the neck, before the fingerboard goes on. The T-nuts work very well, in providing the extra clamping force. But they are dangerous. If the threads get damaged or cross-threaded, it's a real complicated repair. And if the threads seize up, the T-nut can break loose and spin in place. That's a real repair horror story, where you can't even get the instrument apart. I had that happen at least once. Steel screws into steel threads is asking for trouble.

    Yes, I've also tried all the various types of threaded inserts, the ones that install from the bottom. I don't really like any of them. Most of the types can't provide any more clamping force than wood screws. The insert itself rips out of the wood with less force than a screw. I've machined up a few versions which were better than the commercially available ones, but they still weren't much stronger than a wood screw's grip in maple. The big advantage of the brass inserts, which are somewhat of a fad these days, is that the neck can be bolted and unbolted a hundred times with no real damage. Steel machine screws into brass work well, and won't gall or seize.

    These days, I use machine screws threading into inset brass bars. The bars are set into routed slots in the neck from the top, before the fingerboard goes on. The bars have plenty of surface area to clamp down on the wood. The screws are 10-32 stainless socket head cap screws. On the back of the body, I use a neck plate machined from 1/4" thick aluminum, with counterbores for the heads of the cap screws. It's a very solid system, almost indestructible. And the extra clamping force does make a significant difference in the sound.

    I came up with this design around 2003, and have used it in all of my basses since then. I also use this design in almost all of the necks that I machine up for Mike Lipe's guitars and basses. It's interesting, because Mike sometimes gets orders for guitars where the customer insists on standard wood screws. Because they just know that wood screws are better. So Mike has tested guitars side-by-side that were identical, except one had the brass heel bars and the other had wood screws. The difference in sound wasn't tiny, it was very obvious.

    By agreement, I only use this design on my own basses and necks for three of my Luthier clients.

  18. Frederiek


    Aug 8, 2016
    Wow. And thanks for sharing these insights!
  19. JIO

    JIO Gold Supporting Member Commercial User

    Jun 30, 2010
    Oceana (Pacifica) CA
    musician/artist/owner - Gildaxe
    I read through each post thinking, what would Bruce Johnson have to say? :)
  20. Bruce Johnson

    Bruce Johnson Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    I do the same thing.

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