Liutaio Mottola Stringed Instrument Design



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Calculator converts to/from decimal inches, fractional inches, millimeters. Popups must be enabled for this site. From the Liutaio Mottola lutherie information website.



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Frequently Asked Questions

Most of the questions people ask about lutherie fall neatly into the how-do-I-get-started category, and these are addressed in the Information for First Time Builders section.  Questions that are asked more than once and don't fit neatly anywhere else and that I find interesting are found here with short but hopefully useful answers. Mine is not the last word on any of these subjects and I would encourage anyone with a question to ask around and get as many takes on it from as many knowledgeable people as possible.

The questions are arranged here more or less in order of the frequency in which they are asked.

Last updated: September 28, 2017



Q: Do people really ask these questions?

A: Yes, frequently, although some are composites, reworded to ask a more general question.

Q: Where do I get wood and parts for making stringed instruments?

A: You get lutherie supplies from a lutherie supply house. A Google search with the terms lutherie supplies will turn up a number of suppliers. You will not find lutherie wood at the local home center or lumber yard.

Q: What does Liutaio mean, and how do you pronounce it?

A: It is the Italian word for luthier and it is (roughly) pronounced loo TIE oh.

Q: How can I purchase one of your instruments?

A: All of my instruments are built for non-commercial research purposes. Some research yields instruments which have no practical musical application and these are recycled. Some instruments I keep around for further experiments, and some are on long term loan to professional musicians for evaluation and feedback. Most of the remaining instruments are donated to charities. These are generally auctioned off on eBay or put up for consignment sale somewhere. There are plans for most of the instruments on this site. Any competent luthier can build you an instrument from these plans, so if you really have your heart set on one of these instruments and it is not available you may still be able to have one custom built for you. Looking for a luthier to build one of these instruments? Your best bet would be to check out the links page of the Guild of American Luthiers website and find some luthiers in your area. Point them at the plans on this website. I know of a number of luthiers that build from my plans too, so if you don't mind dealing with someone that is not necessarily in your town, please contact me and I'll try to recommend someone to you.

Q: I have this instrument. Can you tell me what it is / how old it is / how much it's worth / who can fix it for me / where I can get parts for it?

A: Sorry, no. For good advice on this subject, see the GAL FAQ page.

Q: I want to build/have built a solid body/semi-solid body/hollow body electric guitar with a neck made out of this wood species and the body made out of that species and the neck joint using this construction technique. Do you think it will sound good?

A: Yes. It may come as a surprise to a number of musicians that there is no definitive research showing any kind of correlation between wood species or basic construction techniques used in electric guitars and particular tone coloring. My advice here is to pick materials that you like (for whatever reasons) and not to worry so much about how this may affect the sound. Paying attention to the ergonomics and weight of the instrument will be far more fruitful.

Q: What kind of glue should I use to put my guitar together?

A: Any kind you like. There is no research showing any kind of correlation between the glue used to assemble a guitar and goodness of sound quality of the instrument. The three most common types of glue in use are standard woodworking glue, hot hide glue and hot melt (glue gun) glue. The latter is used by some large manufacturers. Since there is no research showing any compromise in tonal qualities based on glue type, you can select the glue you will use as you would any other engineering material, by the specs that are important to you. Note that you do not have to search too hard to find all sorts of examples of glue worship, always of hot hide glue. These missives sometimes include detailed descriptions of experiments that purportedly show the superiority of that glue for use in instrument making. But these usually address either some marginal case or some irrelevant physical property. Again, the only experiment that matters would be one that shows audible superiority of instruments made using that glue, and no such experiments exist. So use whatever you want, for whatever reasons. You can't go wrong.

Q: Should I believe claims made by manufacturers about the superiority of their instruments or strings or whatever?

A: I get a lot of questions, mostly from musicians, of the form “Is it true what manufacturer A says about their instruments being superior because of B, which only they have?”. And for the most part my answer is always that if their product was indeed superior everyone would be buying it. I have nothing against companies trying to make money, and it's only natural to make positive claims for what a company believes sets their product above the rest. But musicians should take all marketing hype with a grain of salt. Truly useful innovation is rare. When choosing an instrument all that matters is if the instrument works well for you. And please, of all the reasons to buy something the fact that someone famous uses one or claims to use one is probably the worst. These famous folks are getting paid (one way or another) to use or endorse products or companies. It is interesting and somewhat saddening that the recent addition of lutherie supplies to the product line of an established importer of cheap oriental tools also includes this low rent form of marketing. I guess no field is immune. But as regards celebrity endorsement of anything and whether you should consider it meaningful (or consider it at all), my answer is no.

Q: The articles on this site include lots of technical info that I don't understand. Is it really necessary to know all this stuff to make stringed instruments?

A: Absolutely not. I'm an engineer, and so I approach lutherie from an engineering perspective. But there are a lot of very successful instrument makers that take a far less technical approach to their work. You can build great stringed instruments without a lot of technology and without a lot of technical knowledge. For me one of the great joys of lutherie is just how many different approaches can lead to great sounding instruments.

Headstock of an Uccello Grasso acoustic bass guitar

Q: I read a lot about tap tuning the plates of instruments, but I still don't understand what this is all about or how I can develop the skill to do this. Is there anything specific I should do, or will this skill just come over time?

A: I don't know. The subject of plate tuning by tapping and other methods is one of the ideological mine fields of lutherie. Some folks do it and others don't. Some have strong feelings on the subject. To the best of my knowledge none of the large guitar manufacturers use this technique and a number of hand builders don't use it either. I don't use any form of tap tuning in my own work. This is not to say I don't believe the technique may be useful, but I've not seen any kind of correlation between the quality of the tone of a finished instrument and whether or not the builder tap tuned the plates.

Q: What about free plate tuning? Surely this is more scientific?

A: Free plate tuning is the process of adjusting the plate(s) of the instrument prior to assembly in an attempt to optimize the tone of the finished instrument. In the violin world this is a well-established technique with solid physics behind it. The modes of vibration of the tops of good-sounding violin family instruments have been fairly well established by experimentation. Violin tops are classified as vibrating shells, and this class of structure vibrates in pretty much the same way whether they are free or glued down to the ribs.

Things are vastly different for "flat top" guitars and similar instruments. Here, no correlation between perceived goodness of tone and plate tuning has ever been established. The tops of these instruments are classified as plates, not shells, and their vibration is vastly different when they are free compared to when they are glued down. Is it possible that there is a correlation between the tuning of the free plate and that of the plate when glued to the ribs? Yes, but it is highly unlikely. For this to be the case one would first have to demonstrate that there existed one and only one configuration of the free plate that allowed it to vibrate in the manner it does. For the simple free plate "tuning" that is often done (looking for a certain pattern of vibration at low frequencies, or identifying the frequency of the lowest vibrating mode) it is quite simple to unequivocally demonstrate that this is not the case - multiple constructions of the top could result in the same pattern of free plate vibration, and these constructions would result in quite different vibration of the plate when glued down. And even if it could be demonstrated that only one configuration of the plate results in a desired tuning pattern, there is solid research (here I refer primarily to Evan Davis' brilliant PhD thesis which presents, and validates, a model of guitar top vibration) indicating that the rest of the structure (ribs and linings, in particular the body outline shape and the structure representing the boundary conditions of the vibrating plate) is of major importance to the manner in which the bound plate will vibrate. All of this conspires to make it extremely unlikely that free plate tuning can have any significant predictive or optimization effect on the vibration of the bound top, except possibly as a first order approximation of top mass and stiffness, which can be done by simply sticking to established materials and dimensions. As with tap tuning, I've not seen any kind of correlation between the quality of the tone of a finished instrument and whether or not the builder tuned the free plate.

Q: There is this technique where the top of an archtop instrument is "tuned" by detecting the pitch that the braces emit when they are struck. How does this work?

A: OK I'm a little slow, but with some followup questioning I'm beginning to figure out where all of these requests for specific information on various top tuning mechanisms are coming from. There are basically two classes of these questions. In the first class, questioners want details of how to perform the specific technique of interest. It is, from the questioner's perspective, a reasonable request. The technique in question is usually technical in that it involves some instrumentation. So to this class of question, here's my answer: I don't know, because I don't use this technique. I don't use it because I've not seen any kind of correlation between the quality of the tone of a finished instrument and whether or not the builder tuned the plates in any way. So if you want "how to" info on any of these techniques your best bet would be to locate a proponent of the technique and ask them all about it.

In the second class of these questions, questioners are looking for someone other than a proponent of a tuning method to verify the technical soundness of the technique. Here too I can't really help you. Of the tuning techniques I am familiar with, some defy basic laws of physics and others are technically feasible. But feasible or not it still all comes down to this: I've heard many, many instruments built in many different ways and have never heard a correlation between goodness of tone and the method by which the plates were tuned or if they were purposely tuned at all. So although it might be interesting to have a theoretical technical discussion about the possible merits of such systems, I can't see any practical advantage to systems that produce no quantifiable audible effect.

Q: Will keeping up with the research on instrument acoustics help me to make better instruments?

A: Folks with technical backgrounds will find it is not too time consuming to keep up with the research literature. There is simply not that much of it. And if such things interest you there is some fascinating research going on. But I'd have to say that for the most part keeping abreast of the current research will not necessarily result in better instruments. I base this on the same empirical observation noted in the answer about tap tuning. There are exceptionally good instruments built by folks that pay no attention to the leading edge of instrument acoustic research and I can see no correlation between the quality of the tone of finished instruments and how closely their builders kept up with the literature. The problem with the practical application of current research in any field is that statistically most of the practical conclusions one could come to from the most current research will eventually turn out to have no practical significance, or even to be flat-out wrong. This is by no means a slight to those involved in research. This is just the way research works. There are always a lot of false starts, paths taken that turn out to be the wrong paths. This is simply the way it is on the leading edge. So if you enjoy following the research and have the technical ability to do so then by all means do follow it. I do and I love doing so. And if you have an experimental streak in you too, then by all means give in to it and make some experiments in your building based on research that strikes your fancy. I do that too. But no one should feel they have to slog through material they don't enjoy just to try to glean some advantage in their instruments. As mentioned, doing so will not necessarily make your instruments better anyway.

Q: I want to quit the rat race and become a luthier, making instruments by hand the old fashioned way and selling them.  Can I make a living doing this?

A: In my observation the answer is no in all but a few cases. There are lots of folks doing this kind of work, but if you look closely you'll probably find a lot of sources of supplemental income (working spouses, trust funds, retirement funds, etc.; and income from teaching, writing books, repair work, selling materials and parts, etc.). The basic economic fact is that you are attempting to compete in a market where the dominant products are currently manufactured in highly mechanized, highly automated or off shore facilities with cheap labor (or worse yet, in highly automated off shore facilities with cheap labor!) and that will make it tough to compete with a hand made product. With modern manufacturing techniques and automation it is certainly possible to reduce the manufacturing overhead of even a one person shop. But you'll still need to deal with the sales and marketing of your instruments.

So by paying strict attention to business practices and current technology it may be possible to run a small shop that makes you some money. But keep in mind that for most folks the idea of “quitting the rat race” does not include dealing with all the realities of modern business.

Cradle to hold guitar while routing binding ledges.

Q: You use a lot of weasel wording in your papers like “in my observation” and “current research indicates” and such. Why don't you just state the facts?

A: Well first off, I try to be objective but realize there is no absolute objectivity. And the state of current real scientific research on issues of instrument design and acoustics is not all that advanced. We really don't have a lot of facts in a lot of areas, and I'm loath to fill the void with opinions just because there is a void. So I'm not being lawyerly per se, just trying to point out those gray areas where they exist. And I enjoy mucking around in the gray areas!

Q: Who's that gay blade in your logo and what the heck is that instrument he's playing?

A: That is the poet Philotes from a 1510 etching by Raimondi. In the original he is playing a vihuela (small renaissance guitar), but in my logo the lucky guy is playing a Liutaio Mottola Uccello Grasso (Fat Bird) archtop acoustic bass guitar.

Q: How come all your instruments have Italian names?

A: Master guitarmaker Bob Benedetto uses Italian names for his instruments and I want to be just like Bob when (if) I grow up. Besides, all the good English names have already been taken.

Q: I want to design guitars and other stringed musical instruments. Where can I get all the formulae, data tables, etc. needed to do this? The construction books have little of this information, and even the more physics-oriented books don't seem to have everything.

A: Fellow engineers and other technical types are always surprised to find out that musical instruments are designed primarily by interpolation and extrapolation from existing instruments followed by design iteration, and that there is really little in the way of hard data and formulae that can be of any help in the process. One might think that at least the physics involved with dealing with the static forces exerted by string tension would have been completely figured out by now, but even this is not the case. Consider the simple case of the design of the neck, basically a simple beam. But it is a simple beam with an odd shape, that is tapered, made of heterogeneous materials, possibly contains an adjustable truss rod, and subject to the wedging of frets pounded into one of its surfaces. From this you can get an idea why no one has taken the time to fully specify the math that describes its behavior. Now consider the dynamic behavior of a guitar top, which is oddly shaped, slightly arched, made of an anisotropic material, multiply braced, and subject to torsional distortions imposed by the bridge. You should be able to get an idea of just how hard this problem is. Don't get me wrong, it's not that this couldn't be done, it's just that there is little impetus for anyone to take the time to work this all out.

But I would encourage anyone with an engineering bent interested in lutherie to take a look at Mark French's book Engineering the Guitar: Theory and Practice. In the book you'll find not only all of the formulae and data that are actually used in practice but also the current state of the research in areas where firm engineering data is not yet available. If that book is too technical for you then I can highly recommend Mark's second book Technology of the Guitar.

Q: I want to build an instrument with a top made out of graphite covered balsa. Do you think this will be successful?

A: This is representative of a class of questions, where the person asking wants to do something out of the ordinary – non-traditional, materials, non-traditional design, or non-traditional building technique. Sometimes the subject of the inquiry is the latest hot experimental technique. My rather oblique answer to this class of question is always the same, and since I don't know the answer, it is itself a question: How are you going to determine if this change you are making is successful? Lutherie neophytes who, by definition do not have a lot of experience in the process, would be hard-pressed to come up with a good answer, since they would have little basis for comparison. So to newbies I would recommend sticking to traditional designs, materials, and techniques until you have a solid understanding how these work before attempting any experiments. About the only qualification I'd make to this recommendation is to use the cheapest of the traditional materials, if only to increase the number of instruments you can afford to make. Once you can reliably build consistent instruments you'll have a base from which to launch experiments.

For the experienced builder, whether or not your experiment can be considered successful will be completely determined by your experimental methodology. The lutherie world is full of experiments deemed successful only by their makers. Experiments involving the tonal characteristics of the instrument are probably the toughest to get right. My personal preference is to model such experiments on modern medical (and in particular, drug) experimentation. Well controlled, double blind experiments with statistically significant sample populations are expensive, time-consuming and tough to do, and may not be appropriate for initial attempts in any case. But without such methodological rigor it is difficult to assert any real conclusions from your results.

Q: How much better will my instrument be if I use the top grade of instrument wood instead of the cheap stuff?

A: If by better you mean better sounding, you may be surprised to find out that there is no evidence that higher priced wood has any advantage over less expensive wood. In fact there is much evidence to the contrary. Anyone who has seen a number of violins built by the Cremonese masters can attest to the fact that a lot of what are universally considered to be the best sounding instruments are made of wood which would be considered of low or even questionable quality today. There is a Andrea Guarneri violin with a big (huge!) knot in the top, right under the bridge. In some master violins with two piece tops, not only aren't the pieces book matched, they don't even come from the same tree.

Some lutherie wood.

Q: Why don't you contribute to one or more of the lutherie forums on the Internet?

A: The interactive forums are great places for folks with questions to get them answered. I poke around in them from time to time when I'm looking for survey information on a topic and I'm always impressed with the level of expertise of some of the people offering answers. Generally a questioner can expect to get expert advice there (but usually along with a lot of less-than-expert advice, too). I don't do forums as a rule as I believe they offer a less optimal way of getting the information to the greatest number of people than does a website like this or formal articles in American Lutherie. Forum answers tend to be short and informal and generally less fleshed out than would be acceptable if the same topic was discussed in, say, a published article. This is not to say there aren't very comprehensive answers published by some authors in some forums, but they are the exception not the rule. But the main problem with forums as a means of information dissemination for me is that, once an answer appears in an active discussion it tends to get lost. Used to be, some of the forums were fully indexed by Google or other search engines, so it was possible to actually find information posted in them. But Google has apparently gotten out of that business and currently offers no way to limit searches to discussion groups. Full indexing may have also been dropped for all I know. The search facilities provided by the forums themselves range from extremely basic to essentially useless, making a forum "archive" less an archive and more a black hole. I would personally rather take the time to treat a topic in a thorough manner and present it in a full article in a medium where it will persist and continue to be available. This position has more to do with the fact that my personal situation is such that I have limited time available for this kind of activity and is in no way a criticism of the folks that spend a lot of time and effort answering questions on the forums.

Q: There is conflicting information on your site and on Wikipedia.

A: There is some good information on Wikipedia. As with information posted in lutherie discussion groups, the trick is figuring out what is good and what is not. IMPO the Wikipedia experiment will never be successful until the rules are changed in such a way as to attract real subject matter experts. This will never happen as long as persistent idiots can delete or alter factually correct material. Currently it is more a rich source of opinions than a definitive body of knowledge, at least as far as lutherie goes. And from an editorial perspective the articles tend to be long on minutiae and short on the core facts on the subject. Another way of putting this is that, no matter how many words you have to describe something, you should be thorough about the core description and only branch out into (increasingly minute) esoteric points as space permits. Wikipedia lutherie articles tend to be way off balance in this regard. But I keep my eye on Wikipedia and its successors – one of them may be a viable resource yet.

Q: I want to build a guitar (bass, ABG, etc.) that can be bowed. What do I need to do?

A: Four things - make the fingerboard radius small enough so that individual strings can be bowed without touching others, make the bridge high enough (and possibly the waist narrow enough) so the outer strings can be bowed without the bow hitting the body, figure out a way to orient the instrument so that it can be effectively bowed (for instruments bigger than a viola, this means the instrument will have to be vertical or nearly so), and finally, the instrument must be strung with orchestral strings, as standard guitar or electric or acoustic bass guitar strings can't be bowed. If you consider that all of these requirements make for an instrument which is radically altered, it should come as no surprise that the instrument will now not work all that well as a regular guitar/bass guitar. I would advise against building such hybrids, except for experimentation. Back in the 1960's there was this car/boat hybrid. You could drive it like a car, but it also was a boat. It was expensive, really ugly, and it didn't work very well as a car. Plus, it worked even worse as a boat. Take a tip from this car.

Q: Will you please send me a free copy of one of your articles that was recently published in American Lutherie?

A: Sorry, no. All back issues of American Lutherie are available for purchase. The price is reasonable. The Guild of American Luthiers is a nonprofit educational organization that is funded completely by membership and sales of things like back issues. The organization is well worth supporting.

Q: Do you have sound samples of your instruments?

A: I don't, and the reason is that sound samples are not particularly useful for making instrument comparisons. When you compare two sound samples you are not only comparing two different instruments, you are also comparing different players, different pieces of music, different recording equipment, different recording rooms, different recording processing, etc. and you are (probably) playing these on not-too-great computer speakers. Which begs (or should beg) the question: If you hear a difference between the samples, is it attributable to the instruments or to some other thing or things from the long list of variables that combine to make each sample? Although it is certainly possible for an instrument manufacturer to provide sound samples where all or most of these other variables are kept constant, such samples could only be used to compare instruments from that company.

Garlands and plates.

Q: I have built one of your instruments, or I have built a jig or fixture similar to one you show on your site. Will you put photos and a description of this up on your site?

A: I love to hear from folks about their projects and I am impressed with a lot of the instruments I see and the improvements made to my jigs and fixtures. It doesn't happen often, but sometimes I will ask permission to use photos sent to me on my site. There are plenty of ways to share lutherie information. Probably the best way is to submit your ideas to American Lutherie, the journal of the Guild of American Luthiers.

Q: I bought a guitar and I'm not satisfied with it. I don't think the wood or the finish or the workmanship is good enough. Will you verify that my gripes are valid so I can go back to the person that sold it to me with an expert opinion?

A: Sorry, no. I will not get between you and the luthier that made your instrument.

Q: Why don't your calculators and utility programs generate output directly to the printer? I really just want to print things out.

A: The are two reasons. Most of the calculators generate just a small piece of what is the design of an instrument and I want to encourage folks to integrate these pieces into a comprehensive plan. The second reason, which applies only to really critical dimensions such as fret spacing, is that most folks' computer printers are not nearly accurate enough to use for this purpose.

Q: What do you get when you play a New Age song backward?

A: Another New Age song.