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Pretty sure a wedged joint like the DT would have to be bolted from the narrow end (back of the guitar) pulling the neck down and trapping it in the mortise.

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Ken Cierp

http://www.kennethmichaelguitars.com/

When I toured the Huss & Dalton shop I noticed that they used a butt joint.

who is doing this?
I assume you mean a fastener to keep the neck down in the socket, right?
Interesting idea. I've never seen it.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Like everything else in lutherie multiple ways work in the right hands. For me a tenon with Cumpiano barrel nuts and reinforcement is self aligning and ideal. The self aligning part is especially good in archtops with the higher neck angle.

Years ago I did strength testing with the Cumpiano barrel nut system. Without reinforcing it failed at fairly low torque. With reinforcement I could not get it to fail, the testing jig came apart before the tenon failed. That thread is somewhere in the archives.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Thanks Terence. http://luthiersforum.com/forum/viewtopic.php?f=10101&t=21550&hilit=neck+strength+testing

Since the dovetail locks as it is pushed down into the neck block then logical place for a bolt would be in the bottom of the neck block up into the dovetail; there would be structural issues doing that. I suppose it could be modified to work somehow but has no appeal for me.

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Steve Smith
"Music is what feelings sound like"

Oh okay I get it now with the bolt on DT...



I think I remember a thread here that people were saying that they glue in the barrel inserts. I went on to reply that it didn't make sense to me to do that as the brilliant idea behind that is that they would self align in particular for future neck resets but I never got a reply back. Perhaps I misunderstood it but maybe someone will chime in on if and why they would glue those inserts in.

Another question for M&T makers, do you leave a space in the pocket in the back for future neck resets so that all you have to do is floss the heal without even removing the fretboard?

Use a screw, not a bolt. The dovetail can only loosen by moving up, toward the fingerboard. If the fingerboard is glued down, it's pretty well stuck anyway, but just to be safe, stick a screw through the headblock and into the endgrain of the neck to pin the dovetail against any upward movement. You might have to make a new hole after resetting the neck since the old one won't be perfectly aligned anymore.

I have the remains of a Taylor 12-string butt joint neck that failed by breaking off through the lower threaded insert. Either impact or over torquing can cause that. The NT neck is at least somewhat less prone to catastrophic failure, simply by the fact that the heel is enclosed within the pocket, so that the pieces don't fall off, and may actually help hold the neck on when it fails.I don't know all the details of how the hardware is installed, and this is one of those places where details can make all the difference.

I have also seen Taylors with loose neck bolts; an open invitation to snug things up.

In aircraft construction the rule is that any bolt in a wood structure should be a tight fit, so that it has to be tapped in with a hammer. The objective is to have full contact all around so that any sideways load is spread over the entire width of the bolt, rather than being a line load in one area, which concentrates the stress. The same would hold for round cross nuts. If you can't make a tight hole, at least flood them with CA to help distribute the force.

I usually leave 1mm or so.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

You see.... I knew that my post would get that reaction. And people have argued against it for years, and yet like I said, it works for those who do it. The only point to it is that you don't need to use glue with the dovetail. IF the dovetail is fitted properly, regardless of the hardware going into it, it won't loosen up as some have suggested. And no, you don't need to put a bolt going in the downward direction. I won't divulge the names of those who I know are using this because I don't know if they want anyone to know it. The best hint is, if done right, a dovetail isn't a sliding fit as some would think. It is an interference fit, and "pops" or "snaps" as it seats into its final position, very snug and secure both in the front and back. So a horizontal pulling force on one side won't actually change the internal forces on the members of the joint.
Does that help?

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

No.

Don,
I'm not questioning your position, but I am having a hard time following what you are saying. In your first post you wrote:

And continued in your second post with:

If you were to use a bolt in your dovetail, where would you put it and which direction would it go?

This is an interesting thread!

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George :-)

That's a really intersting guitar and sounds amazing!

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

The same direction as what folks use now. People are assuming that since a dovetail slides downward into final position, and slides upward to be removed that the bolt has to come from below to hold the thing together. Not so.

As I mentioned, the joint is almost an interference fit. Perhaps a friction fit is a better term, but the heel cheeks and the dovetail all hold it firmly in place. The bolt just needs to keep it locked there and remove the ability to move. You could accomplish this in a couple of ways. As I said, with a bolt through the neck block into the dovetail tenon, or with a pin or tapered pin. My method would be to employ my standard fretboard extension on the neck, and then use a couple of bolts through the bottom of the FB extension on the neck block into the FB extension of the neck.

Here's a quickly done model of my typical neck block so you can see the pocket in the FB extension part of that, so you can visualize what I'm saying. There's an extension on the neck that goes out past the tenon on the neck, at the same height as the fretboard gluing surface that keeps a solid hunk of wood under the fretboard way out into the guitar body, pocketing into the neck block, and then held down with two small socket head cap screws. Of course there are threaded inserts in the nexk FB extension part.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

^ but that's not a dovetail Don. That makes perfect sense to me as illustrated but if that was a dovetail instead of the M&T as shown then the dovetail would essentially just act as an M&T so there is really no point in going through the trouble to make a dovetail. If my understanding is correct then the bolts in that case pull the shoulders of the neck into the sides (neck block) and act as the opposing force to string tension. If it was a dovetail the string tension would be pulling the cheeks of the dovetail pin against the cheeks of the socket to act against string tension.

Maybe I am misunderstanding the whole concept IDK.




I agree that is a cool guitar.

Martin dovetails are strung up dry all the time. With just a clamp holding it down during a re-set.
Don, I assumed you were proposing a dry dovetail joint held down with something like a fingerboard extension bolt, as in your drawing or a Taylor. No?
I guess I still don't quite get what your proposing.

I know, but it was easier to model this real fast for image purposes. Substitute a dovetail socket instead of the mortise...




Yes, sort of. Just replacing the M&T with a dovetail, but driving a bolt/machine screw into the face of the heel in the same way.
With my M&T joint, I use two bolts into the tenon, and two up into the FB extension. I would do the same with the dovetail joint, except maybe only one bolt into the dovetail. No glue.

Starting to make sense now?

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Powerfull tool this internet.

Guess I don't see any advantage of replacing the M&T joint with a "bolt-on" dovetail. Just extra work as I see it. Of course it won't hurt anything if that's what you want to do so if you give it a try let us know how well it worked.

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Steve Smith
"Music is what feelings sound like"

Yipes! I'm with Steve adding yet more mating surfaces to (in my opinion) the joint from hell -- not for me. But if you can make it work -- good on you.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Thanks for the explanation and image, Don. I get it now.

I've only used a dovetail joint on three of my guitars (M&T for the rest). They are holding up fine but the last one was tough for me to finesse into a proper fit. It made me nervous because it just didn't feel like it was going to "snap" together well enough to be trustworthy. Lacking confidence in the glue alone, I decided to drill a hole through the neck block, install a threaded insert into the tenon and bolt the joint together as well. I don't know that it was necessary, but the heel hasn't budged. Now that I think about it, I'm going to remove the bolt and see if it continues to hold.

Interesting that H&D uses a series of pins in their butt joint to keep things aligned. That seems like a good approach to me.

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George :-)

The point of the dovetail is that you can string it up unglued or unbolted and it will stay together, which is great for setting the neck and doing setup work. You can't do that with an M&T joint... you have to keep unbolting it, which is a pain.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."