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So, the question now is...can I make this shape into a nylon string guitar. My first build...but I want to do a cutaway.

http://www.stewmac.com/shop/Books,_plan ... ml#details

Can one build any shape and just brace for nylon strings?
Then of course...How do I get that bend?
I want to find answers to questions before I engage in any wood purchases. Just in case this is too daunting of a project (I doubt it). Thanks.

It would probably work, but you would have to re design all of the bracing inside. That guitar is designed to support the pull and rotation of steel strings, much less of an issue with nylon, which would mean with that bracing, you wouldn't get much top driving capability out of the lower tension nylon strings. If you want nylon strings, particularly for a first guitar, it's probably better to work with a plan that is designed to receive nylon strings. It will improve the outcome, if you don't have to reinvent the wheel.

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Waddy

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Sound Clips of most of my guitars

Alan,

Take the time and visit Matt Mustapick's website. There you can visit his shop reports and go through some very good actual photo's and processes he uses in constructing a nylon crossover guitar. It is basically a steel string design that incorporates a lattice style bracing pattern and a thin top. I am currently binding a lattice build now and the top taps extremely well. I'll know more once I have the neck and strings on but so far so good.

Just as a side note, I used a Martin 00 plexiglass template to make all my cuts and jigs. A cutaway is a great idea, however, I would recommend you get comfortable with a basic build before you try to get so adventurous.

Ray

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Guitar Building = Continuous Improvement Process

It seems as though most people forget that the 12-fret 000 guitar was designed by Martin when they used gut strings; in fact, it's one of the largest 'classical' plantillas ever. This should set off some bells in people's heads.

From what I can see, the main differences between steel and nylon string guitars all stem from the differences in the strings. Nylon strings have maybe half of the pull of steel, so you've got only half the energy to work with. More importantly, nylon, as a material, has much higher damping than steel, so it tends to 'eat' the high frequency components. Add to this the fact that nylon strings are much fatter than steel strings, so there is a lot more air drag involved as they vibrate. This, too, tends to 'eat' highs.

I was able to measure the results of this in my string experiments. If you pluck a steel string and a nylon string tuned to the same pitch, at the same place, the initial wave form is exactly the same. You have the same relative amount of power in all of the string partials. Within a second or so the nylon string has lost essentially all of the energy it had above about 3000 Hz, while the steel string is still going strong out to 5-6 kHz. Thus, IMO, the central design problems are different between steel and nylon string guitars.

On the steel string you're trying to get enough low end to balance out all of the high frequency sound in the string. This favors a larger box, which works out well since you have enough power to drive more top area and mass.

On a nylon string guitar, the problem is to make the most of the small amount of high frequency energy you have. With less power to work with, you want to make the top smaller, which helps achieve the right tone, since small guitars do tend to be more 'treble balanced' anyway. As you make the outline larger, it becomes harder and harder to get a really good tone with nylon strings.

I've made a couple of 12-fret 000 classicals, and they work well. I used the standard X brace scheme, but lightened up on both the top thickness and the braces by quite a bit. One of these in my 'Autumn' portfolio guitar, which you can see and hear (in my bad playing) on my web site, under 'New Work' (even though it's not particularly new by now). I don't think I'd go much bigger than a 000 size, though.

BTW, the original Martin gut strung guitars used pin bridges, which were common enough on classical guitars made outside of Spain at that time. I would advise you to use a Spanish-style tieblock bridge, though. Too many people see a pin bridge and automatically put on steel strings. We had an 1844 Panormo come in that way one time: luckily the bridge chipped before he got the steel strings up to tension, or they'd have ripped the one-piece top right off a very nice little collector's item.

Alan, did you get any data off of the Panormo? I've got a real soft spot for those.

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Expectation is the source of all misery; comparison the thief of joy.
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Douglas Ingram asked:
"Alan, did you get any data off of the Panormo? I've got a real soft spot for those."

No, but it was such a sweetie that I made one more or less like it, with a short scale, a few years later for my daughter. The sound was similar enough that I gather I got it more or less right.

The most interesting thing about it is that the 'main air' pitch was so high, at about 120Hz (B), and the 'main top', 'main back' and 'neck' mode pitches were all within about a semitone of each other near 250. I kept trying to drop the back pitch, and couldn't do it: it was more or less of 'locked in' to the only available space. The sound was very 'open' and 'light', but plenty loud enough, and the bass, despite a bit of 'nasality' was not dissapointing.

On a similar sized 'pseudo-Baroque' (it had six courses instead of five) with deeper sides the 'main air' pitch was up around C, instead of near G as one usualy sees it on modern instruments. The paper rosette cut down on the power of the air mode a lot, too, so that the resuting sound was quite 'treble balanced' and 'forward'.

I keep meaning to make another one of those little guys: the sound is quite nice, and 'different', and they sure are handy to play on!

Thanks Alan,

I've got one that I just finished binding. I'm really looking forward to trying it out!

I feel like I'm working blind on this one, I hope that I get it close.

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Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/