Neck joint again

[Yonkle]

I am jumping in, not for any advise, just my thoughts on the neck joint. I have built 12 mandolins all with dovetails. I use a bandsaw, chisels, files,ect. I don't know why, but I can not find a easy way to get that dovetail consistant. In fact over the years it has turned into the one part of the process I dread now.
I have never tried Rogers dowel joint, but I saw a video on youtube of John Sullivan (rip) doing the Siminoff joint with no dowels, and it looked so simple, and everyone says the alingment, string angle is alway perfect, using that jig for gluing.
So, I have told myself, when I get my new shop built, I am going to try the Siminoff joint. The reason I have not tried it, is because I have looked at the dovetail as something I need to perfect and changing would be defeat! Well, I have no pride on this issue, I know when I licked, that dovetail has beat me up too many times, I am going to wave the white flag and try something new!
I agree with John the dovetail is a perfect joint the way it works is genius, (when done right) I either need someone to coach me on a different way to get a good dovetail (everytime) or change. With me it hit and miss with the dovetail, and I can't afford to start a neck over, but I have, and the time waste is horrible, yet has to be done if you have a bad joint.
Just my thoughts! I've made some perfect fit dovetails, and have ruined a few necks. If the Siminoff joint is simple always the right pitch and holds, sign me up! JD

[peter.coombe]

Yonkle you must be doing something wrong. I have used both joints, and would pick the dovetail every time. From memory I think I have made around 40 Siminoff joints and about 75 dovetails. None have failed, so I don't think there is much difference in terms of realiability. The dovetail seems to be the joint that you never seem to stop learning how to do it just a bit better, so practice makes perfect, although I never seem to reach perfection. I think I only stuffed up one dovetail beyond recovery, some have been shimmed, but it is ok to shim a dovetail. I started off using a sliding dovetail, but then switched to the tapered dovetail. I have the dovetail doing process on my web page, you might like to take a look. Not sure what tips to give, other than patience, razor sharp chisels, and keep those shavings fine.

[sunburst]

Just a thought, I've probably fit more dovetails re-setting Martin guitar necks than building mandolins. They always have shims, that's how you re-set a neck. I don't worry if I miss on a dovetail and have to add shims, it happens sometimes.

[Jim Hilburn]

I just did a dovetail yesterday and took a few pictures. I posted how I did it once before but it must have been 4-5 years since I've had my Delta saw that long and I did it that time on the old Craftsman.
I didn't do a thorough set of shots of the layout but I posted that within the last couple of years. There were quite a few other methods some others posted but this is what I settled on.
I started with a piece of cardstock paper with crosshair lines dead center of the paper. The long line is center and the crossing line is the 14th fret. I align the body to center and line up the 14th location and trace the nose onto the paper.
Others use a plexi template for this but using this method I get the exact shape of this particular instrument.
I then align the fingerboard to the 14th and center and trace that. Now draw on the shape of the dovetail, cut it out with an Exacto and you have body and neck templates.

[sunburst]

Now Jim, you know that's wrong! You put the neck on the center line! You'd better move it over toward the scroll if you want it to be right.

Seriously, that could be a big help for folks...in fact, I should probably do that myself instead of just drawing in on the parts and cutting, like usual.

[Jim Hilburn]

Here's the tilt guage, and the first body cuts. Stay inside the line and then make a few extra passes to remove excess. You can't go too far or you'll start cutting into the other side. Make your first neck cut while the table is tilted. Then you can tilt it to the inside for the next tapered cuts.

[Jim Hilburn]

Here's the neck cuts. Lynn showed how he made the box that holds the neck at the correct pitch, but instead of cutting the profile to the exact length for the heel I leave it a little long and that gives me a stable platform to hold the neck for cutting. The back of the neck is cut to the pitch you want and the bottom is 90 degrees to that.
Like I said before you want to make each of these 2 cuts while the table is tilted for the body. I also have to use a riser board on the table and remove the fence rail so the peghead doesn't hit the table while making the cuts.
Once the 2 taper cuts are made, it's time to bring the table back to level to make the cuts that match the body. I did it with the 1/4 " blade but it's probably a good idea to switch to an eighth. There will be an area at the bottom where the cuts don't meet. You can try tilting the neck on the bandsaw to finish it up but just to be safe it's probably better to do it with a coping saw.
If you've stayed within the lines you will end up with this kind of fit, with lots of hand work to bring the neck into alignment. If you want to get closer than this make the pencil lines disappear but you may end up shimming before you get the proper pitch, depth and alignment.
To get the proper outside taper cuts, watch McRostie's video. I do what he does.

[D.E.Williams]

Jim, any particular reason for using a tapered dovetail instead of a sliding one, or vice versa? I noticed here here that Lynn uses (or once used) a sliding dovetail.

I ask this, because I'm right smack in the middle of drawing all this in my CAD software, and need to decide which method I'm going to use. Either way, the cnc will cut the dovetail. I know it would be quicker with a jig and router and band saw, but the cnc will be more fun for me.

[Jim Hilburn]

Well, it locks the neck in place where you want it, it's narrower at the bottom so you can make a very small heel, of course it's how Gibson did it.

[D.E.Williams]

Interesting. I was under the impression that they did the sliding dovetail. My impression was based on Roger Siminoff's book and plans. I much prefer the tapered dovetail myself, because you can get it tight and lock it with that nice little *pop* that you can sometimes get.

[sunburst]

FWIW, I prefer and use a tapered dovetail, but the advantage of a sliding dovetail is the ability to set the neck higher or lower in the head block. It is a way to adjust bridge height during construction.

[Charles E.]

The dove tail neck joint is tried and true, esp. for F-5 style mando's. Bolt on necks work best with an oval or round sound hole. I use knock down furnature hardware, a 10mm barrel nut imbedded in the neck and a brass, large headed allen bolt through the neck block. It is used with a 3/4 inch wide mortice and tennon, no glue is used in the joint. It works great for me.

[Charles E.]

I can spell mortise and tenon.

[David Houchens]

With a bolt on neck, would it be wise to at least glue the bottom of the heel to the back button to get a little extra support? Not arguing, just wondering. It wouldn't take much to turn that loose should you need to. I think I would just for the peace of mind.

[barry k]

I had used the Siminoff type neck joint on most of the old K & G's (Kratzer and Gresham), until I had one of my mandolins , K & G ,come in the shop with a broken headstock..... that was dropped off the stage by owner. In order to replace the neck , I had to take the back off . With a dovetail I wouldnt have had to do that....Just steam it out like a guitar reset. Charles E. could you elaborate a little more on why you believe a bolt on is better for an oval hole ? I have always used dovetails on them also...with no problem, and they were hybids too with the long scale neck. Im all about for doing it easier and better if I can. A bolt on seems easier.

[Charles E.]

Barry, an oval hole is better because I can put a small ratchet drive, with the allen wrench attached, to tighten or loosen the bolt in the sound hole. With an F style you would have to have a long T-wrench and go through the end pin hole ( very akward ) and loose torque.

Bryce, with my style of bolt on the back does not connect to the neck heel. They are seperate. There is no lack of holding power. I will post pictures of a mock up neck joint in a few days so folks can have an idea of what I am doing.

[Doug Edwards]

This came up at a good time. I've been ringing my hands over cutting my first neck joint. I found a good tutorial at
http://www.petercoombe.com/Neck_and_dovetail.htm

I really like the simplistic look to Jim's method. I gave it a practice run this afternoon. I'll practice a few more time before the real deal.

It's great to have such a resource to turn to with such helpful experienced luthiers.

[Rick Turner]

In my teaching I use a "Spanish foot" neck joint...which is to say there isn't one as the heel and neck block are all one piece. I keep wondering if this might not work at least for "A" style mandolins. In the guitar world, one of the main reasons for doing a dovetail or bolt-on neck is that it's a lot easier to do the finish on separate parts. Since it is totally normal to glue a mando neck on prior to finish...and in fact glue the back on after gluing the neck on, I wonder if it might not be a lot easier...and take up a lot less space...to build Spanish style. The neck block could be smaller, for one thing, allowing more vibrating top area.

I know there's the whole thing of being able to take the neck off...but really...what percentage of mandolins ever need their necks reset or replaced? It may be like building a steel cage to sleep in so if an asteroid hits your bedroom ceiling, you don't die in your sleep...

[MANNDOLINS]

what he said

[sunburst]

I prefer the head block to be a lighter weight wood than the hard maple I use for most mandolin necks, so the Spanish foot method wouldn't appeal to me unless I used mahogany of Spanish cedar necks. It should work fine, though.

[Rick Turner]

Jonathan, that photo induced deja vu all over again for me... You know what I mean?

[Charles E.]

I know there's the whole thing of being able to take the neck off...but really...what percentage of mandolins ever need their necks reset or replaced? It may be like building a steel cage to sleep in so if an asteroid hits your bedroom ceiling, you don't die in your sleep...[/QUOTE]

Rick, I do believe it is more of a concern for guitars then mandolins but as with asteroids, it only takes one.

[Rick Turner]

Charley, understood, but then I'd say it might be more important to be able to take the back off for repairs than to take the neck off, yet the backs wind up bound, making it difficult indeed, and then you've got the back coming right over the heel, making neck removal a hellish thing and assuring the need for finish touchup work, so I don't buy the argument that mandolin necks are made to be taken off easily for resets. They're not like dovetailed guitar necks at all in the sense of being designed to be repairable (not that guitars are easy either in many senses). There's little logic to the logic...as it were. The violin makers and repair techs really have it easy...those things are made to be disassembled.

[sunburst]

I've re-set at least half a dozen mandolin necks without having to remove the back. The reason was almost always a poor neck joint though, or heat stress, so a Spanish heel type joint might have avoided the need for the neck set in those cases. A couple were the result of head block failure, so...who knows?...

[Charles E.]

Just a few thoughts about bolt on's, I guess I like them partly because thats what I was taught many years ago while repairing and building guitars in the first shop I worked at. I just adapted the concept to mandolins. I choose to use barrel nuts rather then screw inserts in the neck because inserts do not like end grain maple. Bolt on's are, for me, limited to round or oval holed instruments. They are a little easier to make, esp the mortise and tenon, but you need to be accurate. The drilling of the holes are critical for proper alignment. Like I said they are not for every one or every instrument but I feel they are valid and I have complete trust in them. I made a quick mock up an example of my neck joint. there are a couple different size barrels and bolt head size shown. also, the hole in the bottom of the heel will haveto have a cap glued on to cover it. Do I think I'll ever have to remove it? Probably not, they seemto hold just fine. And lastly the tapered dove tail is in my opinion a thing of great beauty just for its self locking nature, if I ever build an F-5 that's what I will use. Untill then it is bolt on's for me.