Dovetail neck joint cutting and jig

[robbyfowler6]

so to preface this question; I would like to state that I come from the world of building Strats and teles so my knowledge and understanding of neck joints is much less sophisticated. SO my question is I want to be able to cut dovetail neck joints the simplest and cheapest way possible. So what's stopping me from slapping the acrylic dovetail template straight on the guitar (and neck part) and routing it like a regular electric guitar neck(except not from the top), given that I can line up and square up the template. I see all these guys using $250 jigs that I don't want to buy.(my understanding of the jig and exactly what it does is a little fuzzy) Are there alternate cheaper and simpler jigs to make? Do I have to cut at an angle accounting for neck angle when routing or can I create the neck angle after I cut a 90 degree dovetail joint?

[tadol]

You should look at the Sexauer thread in the custom shop - thats no $250 jig he’s using -

[charles Tauber]

For three decades I’ve used a simple jig that cost me about $10. You don’t have to buy an expensive jig.

The approach I use sets the neck angle first in the neck portion of the joint and then cut the joint. The body portion is cut at right angles.

[robbyfowler6]

Originally Posted by charles Tauber

For three decades I’ve used a simple jig that cost me about $10. You don’t have to buy an expensive jig.

The approach I use sets the neck angle first in the neck portion of the joint and then cut the joint. The body portion is cut at right angles.

Aaa that helps me understand it a bit better on the anatomy of the joint. Care to shed some light on your jig?

[charles Tauber]

This is what I do:

https://youtu.be/OjJGER1qTjw

If you have any questions about it, I’ll be happy to try to answer them.

[mirwa]

Originally Posted by charles Tauber

This is what I do:

https://youtu.be/OjJGER1qTjw

If you have any questions about it, I’ll be happy to try to answer them.

With an incra jig as your fence

Steve

[MC5C]

I have two jigs. One holds the body of the guitar up against a template for routing the body portion. I use a dovetail bit. Since the dovetail bit is tapered, and since you route the depth of the mortise deeper than the corresponding tenon on the neck, you can adjust the tightness of the fit by raising or lowering the bit infinitesimally. I have a neck jig that locates the neck using the truss-rod channel, and sets my neck angle of 4.5 degrees. It routes the tenon, and the cheeks of the heel at the same time. You need to prepare your neck blank so that it turns out the correct length, since the cheek cut sets the length of the neck at the 14th fret (in my case, I make archtops). I route the neck tenon according to the jig and a depth gauge so it is a standard size, then I put scrap in the body jig so that I can fine-tune the fit by adjusting the depth of bit, then I route the body mortise. If I do it right I have virtually no fitting or cleanup to do, and the neck fits straight. It never happens that well...

Before I did this, I cut the mortise and tenon with saws and chisels. Both work fine. I probably spent about as long making the jig as I did cutting the joint by hand, so I save time the second time I use it...

[charles Tauber]

Originally Posted by MC5C

I route the neck tenon according to the jig and a depth gauge so it is a standard size, then I put scrap in the body jig so that I can fine-tune the fit by adjusting the depth of bit, then I route the body mortise. If I do it right I have virtually no fitting or cleanup to do, and the neck fits straight. It never happens that well...

That, obviously works.

Just as another data point, I use a fixed router bit depth for each of the two jigs - one for neck, one for body. I don't adjust bit depth to achieve fit. Instead, the two jig components are carefully sized so that they fit correctly using those two bit heights. It usually takes 5 to 10 minutes of final fitting to get the joint to fit properly with correct alignment.

As an aside, I don't use glue in the joint. Instead, I use a single wood screw through the heel block into the end of the neck to prevent the two halves of the joint from sliding vertically apart. The fingerboard extension is still glued to the guitar top, but the joint, itself has no glue. It's a method I learned from Grit Laskin several decades ago.

As a further aside, if one is just starting out, I'd recommend a bolt-on neck attachment. In my opinion, for steel string ("flat top") and classical guitars, the dovetail joint should be retired and better alternatives used. In my opinion, other than as an appeal to tradition, the dovetail joint has outlived its usefulness. It works, and has worked, but there are other attachment methods that have benefits that the dovetail joint does not, the most obvious of which is the relative ease with which the neck can be reset.

[Bruce Sexauer]

The traditional blind dovetail mortise is simple, elegant, utterly effective, and aesthetically beautiful. Fitting it correctly involves some skill which can only be acquired through implementing it a few times. A clever fixture will only get it close, it will require further fiddling if the goal is perfection.

A well constructed medium sized back saw is also known as a dovetail saw. Used along with a sharp chisel and an accurate layout, a steady hand can render a very satisfying neck to body connection surprisingly quickly.

[phavriluk]

Most folks building guitars that post here, I think are first-timers. I think for them to attempt a dovetail is some kind of self-flagellation. There's variations on bolt-on necks that work well, the neck angles are easy to adjust (aka'reset') and allow the builder a chance to actually finish a project. Ain't like the neck attachment is visible from the outside.

To get an idea, go look at Collings' and Bourgeois' necks. And Taylor's in a league of its own.

[MC5C]

While I posted about my jig to build dovetails, I actually use it to cut plain mortise and tenon joints for my bolt on necks. I did a couple of dovetails to prove to myself that I could, they are not my go-to joint. I have evolved my neck joint to a 1" wide, 1/2" deep plain tenon and a matching mortise that I like to fit very closely, it can almost grab when fitting. I use a single "furniture bolt" into a threaded insert that I glue in with CA glue, most of the way down the heel towards the back. I've been putting the insert in the neck, and bolting from inside the archtop guitar with a very long allen key through the tail to do it up, but the last one I was going for a kind of steam-punk esthetic and I put the threaded insert in the head block and screwed the bolt from the outside of the neck heel, left in plain sight as a design feature. One bolt works really well, there is less than 10 lbs of tension on it. I really want to try a Howe-Orme neck joint.

[Rudy4]

Originally Posted by robbyfowler6

so to preface this question; I would like to state that I come from the world of building Strats and teles so my knowledge and understanding of neck joints is much less sophisticated. SO my question is I want to be able to cut dovetail neck joints the simplest and cheapest way possible. So what's stopping me from slapping the acrylic dovetail template straight on the guitar (and neck part) and routing it like a regular electric guitar neck(except not from the top), given that I can line up and square up the template. I see all these guys using $250 jigs that I don't want to buy.(my understanding of the jig and exactly what it does is a little fuzzy) Are there alternate cheaper and simpler jigs to make? Do I have to cut at an angle accounting for neck angle when routing or can I create the neck angle after I cut a 90 degree dovetail joint?

Hi Robby,
I'm not much help with your question, but I would suggest you give some thought to the value of a cut dovetail joint. I personally think a lot of the hand-fit dovetail joints probably have as much air as glue between surfaces that supposidly mate perfectly. Once the neck is glued it's not likely that anyone will ever know.

I did a couple of acoustics using Irving Sloane's brilliant neck joint. It's a straight cut mortise and tenon, but incorporates 2 angled dowels across the sides of the mortise that pull the neck to the body and lock it tightly in place when it's glued in position. Irving was good with the engineering stuff, for sure.

I switched to bolt-on mortise and tenon because of the ease in doing the final all-important heel fitting and also for doing any reset work that might be necessary years down the road.

It's just something to give serious consideration to. If you're new to building then make things as easy for yourself as possible and build in a way that will have a successful outcome.

I've made my share of firewood, been there and done that, and it's not good for the spirit.

[printer2]

Originally Posted by tadol

You should look at the Sexauer thread in the custom shop - thats no $250 jig he’s using -

I was thinking the exact same example as I was reading you original post. Found half on his Facebook page, from Aug 16 2014. Then I looked through Bruce's 2014 diary of sorts.

https://www.acousticguitarforum.com/...335992&page=21