All these discussions on scraf joints inspired me to try something off the map. Uh... unless it's been done before...?
I wanted to 1) angle the body to the neck 2) use frets 3) eliminate the fingerboard 4) reduce the time spent shaping the neck inside the box by keeping the inside wood intact, but adding small spacers to limit contact with the lid.
The resulting join is weaker than a full scarf joint, but I'm hoping three strings on red oak will hold up.
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Like Chickenbone John I'm building fewer through necks.More with a simple joint at the body like this one. The neck angle is achieved by planing the neck top surface so 1/4" is removed at the nut tapering to nothing at the body.If you want a higher bridge lift the neck by adding blocks as in the Guinness photo
Just spotted this. I have some bits of old seasoned oak that I thought were too short for a through neck, but they'll be fine like this. Thanks to TwoShoes for the pics and to ChickenboneJohn for the diagrams !
One of the reasons I've built more "set in" necks rather than thru' necks is down to the length of the available lumber..."needs must when The Devil drives"...
Glad I haven't upset too many people by setting-out my approach...after all, if it works, it's good. To notch out the end of the neck to fit in the box, its just two saw cuts. A good sharp handsaw and a steady eye will do the job...these days I use the bandsaw, but as I said in an earlier post, I did a couple of hundred guitars with hand tools before I started getting any workshop power tools. As for handtools..good and sharp are the key words: a cheap, blunt handsaw will make things much harder than they ought to be. You don't need to spend a fortune, but when a tool gets blunt you need to sharpen it, or in the case of the budget handsaws, throw it away and get a new one.
The reason I often go for a heel that extends well up the neck is that notching the end of the neck to fit in the box (and notching it again to take a magnetic pickup) creates a weak point where the leverage on the neck is at it's most severe, so I try and keep a good thickness under where I'm notching out, and maximise the glueing area. I find that the heel doesn't really interfere with the fretting hand. The heel stiffens the neck and effectively shortens the length that's subject to the bending stresses, making the whole thing more rigid, durable and resonant. I've seen many necks that have been notched to such an extent that this weak point acts as a hinge and the neck really starts to pull forward under string tension - that's why you need the extra thickness at that point, and it's important to extend that thickness well past the notch (by say, a couple of inches), as that is the point where the stresses are highest. The larger glueing areas also helps spread the stress in the glue joint over a larger area, so it's more reliable, less prone to failure and more tolerant of inaccuracies in the joint. Wherever the neck is glued or screwed to the box, the part of the neck 'outboard' of that fixing point is subject to the most severe bending forces (in engineering terms, it's the root of a cantilever), so that's why it's a good idea to extend the heel to stiffen the 'root' of the neck. Past that fixing point and inside the box the stresses on the neck are different - if I didn't have the heel then all that leverage and bending would be exerted on the thiner part of the neck inside the box.
By the way, those stepped or 'joggled scarf' joints on big timber structures are usually designed to resist tension (although they would also resist compression), as they commonly have a square timber 'key' inside the joint to stop the two parts sliding apart under stress. The bolts apply a clamping pressure so the parts bite down onto the key(s) in heart of the joint...it's quite a sophisticated bit of engineering.
CBJ - those'neck partway thru' diagrams are great!! But given that you extend that glue join inside te box I don't know that you really need such a massive heel on there? It's not all that different to what I do at all except I want to avoid te big heel so I glue along the whole length o the box and fix with screws thru the tail and into the end. Great ideas all around and those who dont see the value in a neck angle and a big tall bridge I'd encourage you to try it :)
I may be missing something here...but why are you introducing the notch rather than doing a simple scarf to get the angle? I know it sort of works, but it just seems unnecessarily complicated and more difficult. You are cutting 25% out of the thickness of the neck end, thus weakening it at the greatest point of stress, and the glue joints I see are really thick - a glue joint ought to be virtually invisible in order to be strong. A simple scarf would be easier and stronger. To introduce some angle it's much easier to just glue the pieces together with no angle and taper the part that goes into the body..or do what I do - don't put any taper on the joint, screw the neck to a block running down the back of the box and use shims to introduce an angle.
Heres an illustration...the top two are the was I typically do it. The lowest picture shows a simplified version, but I always prefer to keep as much 'meat' in the end of the neck by extending the joint into the box. These give you a nice simple joint, and keeps the thickness and strength where you need it most. The key point is maintaining continuity, that's why it's better in my opinion to extend the neck well into the box as single continuous pice of wood, keep the notching and cutting to a minimum, and ensure there's plenty of glueing surface on any laminations and joints.
This. . . I like this very much. Another trick to add to the treats. Thank you Chickenbone John for sharing the details.
Chickenbone,
Well, my face is a bit red because you've got called me out in a couple of spots where I deserved it and possibly poked an Achilles heel that will take money for me to adequately cover. It will just have to remain exposed until I am better heeled. =D
It is silly to defend a weakness, so I I'll gladly admit them. But how should I answer direct questions without avoiding or sounding defensive (because I dont ~feel~ defensive! :-D ) Point by point then?
> I may be missing something here...but why are you introducing the notch rather than doing a simple scarf to > get the angle? I know it sort of works, but it just seems unnecessarily complicated and more difficult.
Lack of the right tools, Dude! Compounded by a lack of patience, of course. I don't have the cool setups some of the guys have shown, so I wanted to shape less wood. And since I was going experimental, I decided to eliminate the fingerboard, just for giggles.
ALSO... those short frets in the first picture were also an experiment. I cut to length and knocked the sharp ends off on a belt sander before pounding into slots. Proof of concept. Less ugly than the marks I was leaving with the file, but still unsettling.
NOTE: I've seen $tew-mac and the DIY tools and jigs. I already have a wish-list + a to-do list.
> You are cutting 25% out of the thickness of the neck end, thus weakening it at the greatest point of stress,
Acknowledged from the get-go. Dead on.
> and the glue joints I see are really thick - a glue joint ought to be virtually invisible in order to be strong.
Uh-oh. Really guilty here. I hyperfocused on knocking it together and let a hairline join fall to the wayside. On the upside, it created greater visibility in the photos! It's a feature, not a bug!
> A simple scarf would be easier and stronger. To introduce some angle it's much easier to just glue the pieces > together with no angle and taper the part that goes into the body..
Ah, there's the rub! I was on the "stronger" bandwagon from the start, but easier?... Tools and shop setup! Remember how I departed from the map? I was exploring certain sacrifices to fit my methods to my means.
> or do what I do - don't put any taper on the joint, screw the neck to a block running down the back of the box > and use shims to introduce an angle.
WHOA! I like the heck outta that shim approach! Thanks for the pics. The shim for the bottom is simple enough. How long do you typically make the notch removed from the top? I fear it could put me back in the long cut business. <sigh> (More like long-time-with-hand-rasp-and-why-isn't-this-flat-yet business)
> Heres an illustration... <SNIP for space>
I guess my only philosophical leftover is NOT to disagree about what is stronger or better ('cuz I don't), but to wonder how far I can move from "stronger." Somewhere inside of "failure" plus a nice margin is "strong enough." Yes, good enough is the enemy of the great, but I think it may be another of those trade-off sliders that I see mentioned all over the CBN archives (you know... like the ones where Oily posts pics from the Les Paul museum to illustrate! Thanks, Oily, most helpful!).
Man, I really appreciate your input! I have been semi-stalking you, but am now moving you up my list.
OH... if my experimental joints fail, I'll post to this thread. Uh...unless it takes 5 years or something. Who knows where we'll be!
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