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I have carved two necks at this point. I got the first one from a friend of mine (Steve Brown) who had already cut out the tenon. On the last one I made the cuts for the tenon and everything else (I used a neck block that already had the mortice...) The last neck worked out fine, but I don't remember whether I made the neck angle cut with a 3 degree compensation or if I just cut it at a 90 degree angle and flossed it to the right angle... (I know..., I should keep a journal... ) I am again using a pre-made neck block that is currently installed. I have made a total of 6 guitars. Of those, 4 were with pre-carved necks and 2 were with necks that I carved. I'm planning to carve all my necks in the future.

Cumpiano and Kinkead talk about the angle but don't seem to demonstrate it... Cumpiano shows all the other cuts except this one...

What do you do? Do you cut the angle (3 degrees?) or do you just cut it at 90 degrees and then just fit the neck when the time comes...
Thanks,
Steve

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I cut it with a slight angle just to save a little shaving. Not sure the exact degrees, but keep it on the safe side, or just do 90 for sure safety. Then when you've got the body together, chisel the neck angle to almost right, and floss the last bit. The important thing is not to ever have to adjust the angle forward, because that involves moving the 14th fret further into the body (looks bad), which also changes the bridge position (very bad if you've already glued the bridge).

There is no cut, which is why none is shown. Cumpiano's neck block and heel are set at 90 degrees, the cheeks of the heel are not tapered. The neck angle is actually created by arching the UFB. The soundboard raises to meet the bottom of the fretboard creating the 1.5 degree neck angle. If the UFB is arched correctly the neck angle is very consistent guitar to guitar. I made a template with the correct arch. The UFB arch is increased slightly for the 12 fret guitar VS the 14 fret (where the neck joins the body.)

In Cumpiano's words: http://dolcecano.blogspot.com/search?up ... -results=3

Cumpiano's technique also dispenses with the heel-cutting neck-set procedure.

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It took me a bit of thinking to see what Todd was talking about . but I agree with how the 5 degree cut of the heel face can create a back angle once the heel itself is carved into a tapered shape. However, if you were to cut the heel like this and then stay with a Gibson or Guild style square heel, your neck wont fit very well - you wont have any back set.

But since I dont cut mine this way -here is whqa I do ... take a sliding bevel, andsimply measure the angle on the body where the neck will sit, then transfer that to your table saw mitre gauge. I under cut the angle, thus leaving the neck pichtching forard a touch, and then the flossing and fitting of the heel to the body slowly brings the angle/pitch back into the needed position. I use a butt joint, so the whole heel gets cut at once. If you use a mortice and tenon, then you have to make one cut per side, and transfer the angle from the sliding bevel adn set the mitre gauge twice.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Nope, 90 degrees. That is, if you milled your block precisely as I have. As you can see in the picture, it's a very precise exact 90 degree angle, since my block was cut precisely, that' a Starret. If the upper face brace is curved properly, a 1.5 degree angle will be formed when the arch tips the soundboard back. The neck block tips WITH the soundboard, maintaining the 90 degree angle when the sides and back are glued on. In effect, the SHOULDERS are also tipped back.

Todd would be correct if the neck block didn't tip with the soundboard, but that would only happen if you cut that angle into the neck block prior to gluing. Then at that point flossing and cheek undercutting would be necessary.

As it is, there is no angle cut into the neck and the heel of the neck is not tapered in the slightest. No neck cheek cutting or tapering necessary, and the neck block is still perfectly square all around, though you can't see it. My necks go right on, no flossing or undercutting necessary.

Also, with this technique, there is no falloff or humping at the neck joint, when the neck is adjusted straight, it is straight all the way to the end of the fretboard, allowing easy action all the way up the neck.

It's not an intuitive mental picture. Cumpiano showed me how it works in person in his workshop.

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And just so there's no doubt that I am not simply confused and am making a flat top acoustic with no neck angle as in classical construction, here are some more pictures. The neck is attached, clearly you can see the neck is indeed angled back slightly.
Also, here's a picture of the uncut heel cheeks, a closeup of the unflossed yet tight neck joint, and the height off the top of the guitar where the bridge location will be, a precise 7/16ths inches, as determined by the neck angle. You can see in my previous post that the neck joint is 90 degrees, as is the neck heel. The heel is not tapered in the least.

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Old growth, shmold growth!

Guitarwhisperer? So you rely on the curve of the UFB to arc the top, to the correct amount to set the neck back? Sounds (and you proved it's) possible but doesn't sound practical. What if the arc changes over the course of the build due to humidity changes. Also you're relying on that same brace to remain stable over the life of the guitar to hold the back set of the neck? If you need to make any changes for any reason to the neck set, you'll have to add a shim under the fretboard to compensate for it... yes? Also, the body of the guitar must be sanded to some taper to also create the back set yes? Sort of like using a 25' radius dish to taper the rims....

I guess this is why Mr. C doesn't use a body mold for building, you wouldn't get the neck block angled back in a body mold...Although it's not angle back much, it still wouldn't be parallel to the body mold..unless that was tapered too?

Everyone has their way of skinning the cat and as long as it works for them....this just seems confusing to me, but then I didn't follow the book to the letter when I started building

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So just to be perfectly clear - your heel block isn't "vertical" then right? It's orthogonal to the longitudinal radius of the top right?

Pretty neat. How do you get it to do that?

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The neckblock is precisely 90 degrees to the soundboard, as you can see in my first picture. That's a Starret square, which is pretty accurate.



With the UFB arched, the soundboard tips back, so the string height above the bridge is not too shallow, as you can also see in my pictures.



That's a danger with ANY guitar. If the UFB changes, the neck set on ANY guitar changes. Also, all my braces are hand split and cut by me personally, from soundboard grade billets. This is one area (of many) where I see no compromise possible. My braces have zero invisible runout and perfectly vertical grain, straight the entire length. Nothing is foolproof I know, but I feel I have minimized chance problems, and spruce, if prepared properly from quality stock, is fairly predictable. My UFB is the stiffest and strongest brace I can find. You also have to remember that the guitar structure is a system. The sides, neck block, soundboard, and back all work together. The heel can't rotate unless the UFB collapses and/or the back stretches. Most guitars fair very well over the course of their life, I don't see that there's any greater risk with this technique. It's very easy, amd consistent.



I'd say that's a fairly accurate assessment. This method doesn't lend itself to mold building, in fact a mold would be a hinderance.
If I were mold building, I would get the Woolsen neck jig as Todd stated. As is, I get very consistent results guitar to guitar, with no fuss and minimal finiting.



Correct! Except that the span from the shoulder to the soundhole is flat, the rest of the arch is created by arching the x-braces and lower face braces, so that the soundboard has an overall radius, but the curve straightens for the short span under the fretboard.

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I'm curious about the durability/longevity of the results here.

How many of these have you done this way? and How long has the oldest one existed, and have there been any 'issues' ?

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Jim Hansen

Thanks for the explanation! Makes sense, and like I said, there are many ways to skin the cat, as long as it works for you I say

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

I use a 28' radius on my tops, but the upper transverse brace (UTB) is flat...

I elevate the lower bout by 1/8" and sand the top of the rims at the upper bout (on a flat surface to match the flat UTB) to allow for the necessary angle to ensure that the strings are at the right position over the saddle....

So, if I make the neck cut at 90 degrees, it should achieve the appropriate angle, with perhaps a little fine adjustment when fitting the neck... Is that right?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

Not to answer for the whisperer, but Bill C has been building this way since the book came out in when early 80? The guitar that was built for Taylor Pie was recently sold by bill http://www.cumpiano.com/Home/Scrapbook/scrapboo.htm check on interesting visitors...my guess is it's plenty solid, as there really is very little difference between this method and the Martin method of a square to the mold neck block.

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

My experience is trumped by others.

Cumpiano's been building this way for over 35 years, I know of at least one of the guitars featured in his book is still in use today and still plays well, his book was published around 1985 I believe.

This method holds up over time as well as any other method.

Guitars made with ANY method can have "issues".

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Old growth, shmold growth!

The neck block is 90 degrees to the soundboard. When the soundboard is tipped back by the UFB arch, the neck block tips with the soundboard. The neck block is glued to the soundboard first, along with the heel block, before the sides are glued to the soundboard, unlike most mold-building techniques, where the neck block and heel block are glued to the ribs, before the soundboard and back are glued on.

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Old growth, shmold growth!

If I read you correctly, that sounds about right, since your soundboard will also tip to conform to the rims. Do you use a mold? If so you may run into problems.

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What I really like about this build method is the simplicity of it. If my cuts are accurate, there is no cheek paring, no flossing, very little finiting. And there is no falloff where the neck joins the body, the fret plane is straight to the end of the fretboard.

With the tapered heel and angled cheeks, there is usually some falloff of the fretboard where the neck joins the body, when the fretboard is deflected downward when glued to the soundboard. At least, that's the case with every Martin and most Martin-style builds I've seen. A tapered shim under the fretboard tongue solves that problem, which is what I do when I reset the necks on them.

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What specifically are you disagreeing with? My statement that there is usually some falloff? I'm going by the Martins I've worked on, and most of the dreadnaughts from manufacturers that I've seen.

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Old growth, shmold growth!

The pictures just appeared.

So your UFB is flat, but your top is domed?

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Old growth, shmold growth!

He also said he elevates his lower bout by an eighth of an inch prior to sanding the upper bout flat. This would result in a tipped soundboard, similar to those old Mandolins with bent soundboards but not as dramatic, and in the upper bout instead of the lower bout.He also didn't provide info as to whether or not he was using a mold. I think you misunderstood his question.

With a mold-built guitar and a domed top, your illustrations are what would be expected.

If he's building without a mold, and changing the contours of his rim, most likely he is in fact tipping the soundboard as well, similar to what I learned to do, although my rim plane is straight. In fact, 1/8th of an inch is the arch I use for my x-braces. If he builds on a workboard, and glues his neck and heel block on before his sides, moslt likely the 90 degree neck joint will work very well, with minimal finiting, assuming his neck block was in fact square prior to gluing to the soundboard.


I like what you are doing. I don't have space for a neck jig right now, or storage space for molds and dome surfaces. I guess that's what appealed to me about Cumpiano's method. It was great fun to go up North and spend time with him in his shop, as I knew intuitively that what he was doing would work well for my space.

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Having a hard time getting this visually in my head.

I guess I will have to read this a few more times and sleep on it.

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Something I wanted to throw out there for discussion - I recently started cutting fretboards designed in CAD and it became obvious that it's pretty easy to design and manufacture a fretboard with a very accurate taper from nut to bridge built in to it.

Would it be of any value to use such a fretboard? i.e. if such a fretboard were available, would it help out the process at all? I'm thinking that it would allow 90 degree cheeks on a neck but fine tuning would be difficult.

I can see a problem that in a form built guitar, you'd have to carve a taper on the bottom of the fretboard to get it to match but, that could be roughed on the CNC machine.

Would the taper ruin the way the truss rod adjusts?

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What it all boils down to is that you have to pick a neck alignment system that has a track record in experienced hands and then build a lot of guitars and observe what they do for a few years.
Everyone's instruments move a little differently and settle in a little differently. I'm in the angled upper bout/flat UTB/neck jig camp but as I observe the behavior of my instruments over the years I'm still making little tweaks. At one time I thought I had a "set it and forget it" system but surprises lurk when your babies get out in the real world.

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Yes, they do the same thing but in a different way, and will be affected by the use of a mold or not.

Molds tend to keep the block 90 degrees to the top of the rim created by the sides, prior to any contouring, such as back arching. If the top is arched, the resulting dome raises the angle of the top in relation to the rims, as is seen in your pictures (as you obviously already know.) When the sides and back are glued, the neck block/top angle relationships is maintained. A radiused dish is usually used to contour the rims, kerfing (!) and neck block to the correct angle to accept the soundboard, so the top of the neck block angle is adjusted at that time. You can rough cut the angle into the block ahead of time and finesse it with the domed sanding board. The cheeks can be pared and the neck heel is tapered to compensate, and if done correctly the line from the nut to the end of the fretboard is straight. In a Martin it seems that there's usually some fall-off, at least in all the Martins I've seen.

If a workboard is used with a dome top, the neck block can tip back toward the soundhole, as the block is orthoganal to the soundboard dome (90 degrees to a tagential plane to the soundboard dome) and when the sides and back are glued on, the angle is maintained, in effect tipping the shoulders back, maintaining the square relationship of the neck to the body whilst maintaining the correct bridge height.

If a facet is sanded into the rim instead of doming the top, the same relationships apply. Faceting the rim tips the soundboard back, as the soundboard follows the rim contour, but the use of the mold or not will determine the angle of the neck block in relation to the soundboard, and whether or not the neck block needs to be angled on top to accept the soundboard.

This assumes the mold doesn't have a shim that tips the shoulders back, but why would it?



The idea is that you want the fret plane to be straight from the nut to the end of the fretboard. A tapered bottom would be of no value, it would simply influence the final angle of the fret plane slightly, which would have to be accounted for in the overall design of the instrument, whether or not the rim is straight or contoured, and whether or not you used a mold.

If the top was not domed or arched and if the neck block was square to the soundboard, and if the neck angle was set back at a 1.5 degree angle, then the fretboard over the body would have to be shimmed with a tapered shim. In that case, a fretboard with a built-in shim machined into the bottom of the fretboard where the fretboard touches the soundboard would be useful. That would most likely require finiting of the neck joint anyway, and would not necessarily make it that much easier to get a good neck angle relationship, IMO.

The truss rod function would not be impaired in any way, I don't think.

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Either system can age well or badly, depending on the quality of the materials and the skill of the builder, yes?

I simply don't have the space for the equipment necessary for mold building, especially with my sizeable wood stash, and the fact that I also build electric guitars and basses with their space concessions.

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