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I've been building for about a year and a half now, and in that time I've completed 8 guitars, and am almost finished with my 9th. I've used Cumpiano's book as a general guide when it comes to setting the neck -- that is, the neck set angle is essentially zero. String tension alone will usually pull a sufficient bow into the neck.

This has worked well for the most part so far, although with a couple of my builds I have actually experienced a bit of a reverse bow, which has resulted in some fret buzz. In both cases, the reverse bow developed after completing the guitars. The neck wood -- mahogany -- was well seasoned and stable. Or so I thought. Go figure.

Another characteristic of using a zero neck angle is that my guitars' saddle heights are a bit higher than what I'm used to seeing when I compare my builds to those of some well known classical builders.

Now, I guess I've been thinking that having a slightly taller saddle height on a new guitar is not a bad thing, because over time the instrument will begin to distort because of string tension. When this becomes noticeable, having more adjustment room at the saddle would be a good thing, seems to me. I have a beautiful old classical made in Madrid in 1968 that has no more saddle height left and action that is becoming too high. But then I see the guitars built by Ramirez and Bernabe and Contreras that have minimal saddle heights when new, so . . . ?

It's confusing, you know?

I have Jim Williams' book also, and he actually planes a set angle into his neck shaft before attaching the fingerboard. But the angle he planes into his neck shaft is in the opposite direction that I might want to go, so I dunno if I want to do this.

It occurs to me that if one uses a Spanish foot that one can control the neck set angle by setting the depth of the gluing surface of the Spanish foot. If it stands proud of the sides, when attaching the back the neck will have a negative angle, requiring a taller saddle. If it stand shallow of the sides, this will give one a positive set angle after attaching the back. But my only concern is that the back may appear to be somewhat concave around the foot, and that this might show. Controlling the actually angle could be problematic as well, or so it seems.

I guess one could even cut the side slots at a slight angle as well.

Another concern I have about all this is that I might wind up with a bump in the fingerboard where the neck joins the body. I don't need that, although I suppose I could take that out when I contour the relief for the bass strings.

Anyway, I'd be most curious how others here do this, or if they do not.

Best,

Michael
Michael McBroom38546.438912037

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Live to Play, Play to Live

Michael, how high is your saddle? You typically want to aim for 10mm, more or less.

You can use the heel to set the angle, but not in the way you mentioned.

When you build your guitar you need to decide several things in advance. You need to decide the final fretboard and fret height, the action you want at the 12th fret, and the string height at the saddle. Given that data you can build your guitar to exactly those settings. Without it your guitar will have proper action only by dumb luck.

So here's what you do. Take your action at the 12 fret, and double it (to get the offset at the saddle, naturally). Now take your planned saddle height, subtract that number, to get how high the fretboard should project at the point of the saddle. With me so far? For example, if you want action of 3mm, and a saddle height of 10mm, you get 10 - 3*2, or 4mm.

Make a dummy fingerboard. Make it as thick as the fretboard thickness and fret height combined. Temporarily clamp it to your neck.

Now you can use a ruler to adjust the neck angle. What you are going to do is clamp the back on with a few dowel spool clamps. The spanish foot is going to be sitting on top of the backstrip inlay, so the back will not fully close. This is exactly what you want.

Once the back is clamped on, lay the guitar on the back, put a straightedge on the dummy fingerboard, and just bend the neck until the straightedge is 4mm above the soundboard at the bridge position. Using a pencil, mark where the spanish foot intersects the backstrip. I find this takes about 6 hands to do! Also, the neck will bend a bit under tension, so it's okay to be a bit high, but not too much.

Now, take the back off, and remove the backstrip nearly up to the mark. Be conservative - the backstrip is going to lock the neck into position by butting the spanish foot against the end of the strip. So don't take quite enough off, put the back on with spool clamps, measure the neck angle, take the back off, shave a bit more off, etc. If you do go too far, glue on another piece of backstrip, and try again.

Once it is perfect you can glue the back on, making sure the foot is solidly locked against the backstrip. Voila, your neck angle will be perfect.

With this method you can cut the side slots at 90 degrees to the neck. You really aren't bending the neck much, as you should have come close to building in the correct angle using your solera anyways.

Thanks for the response and the clear explanation of your procedure.

It sounds to me like you glue the backs on your classicals with the guitar facing upward? I glue my backs down with the guitar face down on a Cumpiano-style workboard with 1/8" shim in place to account for the top's arch.

So, I can follow everything you've described, except to the point where I actually glue down the back. I'm not sure how I would insure that the foot butts up exactly against the back graft when everything's clamped down, since I can't see in there to see how close it is.

Lucio Nunez, a San Antonio luthier, recently showed me an adjustable mold he now uses, the design of which he obtained from Tom Blackshear. He now does most of his work with the guitar face up, I believe. Wish I would have taken notes when he showed it to me -- it was a pretty slick arrangement.

Best,

Michael

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Live to Play, Play to Live

Whoops, made a dupe. Lance, you can delete this note if you want.

Best,

Michael
Michael McBroom38546.6687384259

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Live to Play, Play to Live

No, it's glued face up.

Believe me, you will feel it when the foot slides into place. Basically what I do is put the glue on the linings, strategically put on 6 or so spool clamps to hold the back in the right position, then pull gently back on the neck until the foot slides past the backstrip and settles against the back. Hold the neck, and tighten the spool clamps that are near the neck, locking the back, and hence the neck, in place. Do a dry run or two until it all makes sense.

I should clarify that it is not my idea, but I learned it from David Schramm's Online Aprrentice course. He sells the CD on his website, and it is very worthwhile, as he has several tricks like this that I haven't seen explained elsewhere.

I have that original Hauser cd from Schramm also. Well worth the price of admission! I recently noticed on his site under the most recent "online apprentice" pictures, that he uses a different technique now. It's not terribly lucid but has something to do with shims. Have a look and if someone can explain it please do. I will ask him next time I see him, but it could be awhile. Ed Barajas sees him on occasion maybe he knows, Ed????

Most of the work is done with the guitar face down and then he flips it over to fit the back (setting the neck angle) and glues it on face up using spool clamps.

Again that cd is well worth the money for a classical builder.