Posted on September 2, 2022March 5, 2024 by Dale Phillips A Method for the Design of the Guitar Body Outline A Method for the Design of the Guitar Body Outline by R.M. Mottola Originally published in American Lutherie #97, 2009 See also, Parametric Models of Guitar Cutaways by R.M. Mottola A Method For the Design Of the Guitar Body Outline Part 3: Compound Radius Curves by R.M. Mottola One of the most tedious and time consuming aspects of designing a new guitar for me is the process of designing the body outline. The body outlines of my early instruments were the results of many hours of labor, usually over the course of many weeks. This process was so time consuming that I would often forgo it entirely, opting to reuse an existing body outline as is, or scaling up a guitar outline for use in an acoustic bass guitar. But over the years I’ve settled into a method for guitar body outline design which is far less tedious and consumes far less time than did my original efforts. This method involves the use of a standard model of the guitar outline. Use of this standard model helps to make the process of developing an outline more standard as well, and this in turn has resulted in the development of techniques which save time and frustration. In this article I will be outlining the model and discussing some common guitar body types in the context of this model. In talking about the design method which makes use of the model, I’ll try to touch on some of the generic qualities of guitar body outlines and how they can be quantified in terms of the model. Finally, some of the tools and techniques of the method will be detailed. Please note that what I am discussing here is only the mechanical aspects of a body design. Issues of acoustics or ergonomics are not covered. Also note that this method works equally well with either pencil and paper or CAD drawing tools, although there are some differences in how these tools are used. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on September 2, 2022March 5, 2024 by Dale Phillips Parametric Models of Guitar Cutaways Parametric Models of Guitar Cutaways by R.M. Mottola Originally published in American Lutherie #99, 2009 See also, A Method for the Design of the Guitar Body Outline by R.M. Mottola A Method For the Design Of the Guitar Body Outline Part 3: Compound Radius Curves by R.M. Mottola In the article entitled “A Method for the Design of the Guitar Body Outline” in AL#97, I introduced the concept of parametric models for the design of the guitar body outline. That article addressed symmetrical body outlines only. In this article I want to consider parametric models for the body cutaway. Taken together the two articles demonstrate a complete method for the design of typical guitar body outlines. Although it was possible to devise a simple parametric model for the design of the symmetrical guitar body outline that was adequate for most of the “standard” guitar body outline types, things are a bit more complicated where the cutaway is concerned. The basic problem is that, except in the most basic designations, cutaway styles have not yet settled out into a small number of distinct types. Rather than pursue a model that would accommodate all existing cutaway designs, I chose instead to derive basic models for the two primary cutaway types, leaving enough configurability to insure that most existing cutaway outlines could at least be approximated. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on September 2, 2022March 5, 2024 by Dale Phillips A Method For the Design Of the Guitar Body Outline Part 3: Compound Radius Curves A Method For the Design Of the Guitar Body Outline Part 3: Compound Radius Curves by R.M. Mottola Originally published in American Lutherie #103, 2010 See also, A Method for the Design of the Guitar Body Outline by R.M. Mottola Parametric Models of Guitar Cutaways by R.M. Mottola The article “A Method for the Design of the Guitar Body Outline” in AL#97 presented a model for drawing guitar body outline halves based on five circular arcs and three straight line segments, as shown in Fig. 1. Here I will present an enhancement to that model. As the original article pointed out, the five-arc model can be used to draw most but not all guitar body outlines. So it was probably inevitable that the first feedback I received following the publication of that article was from someone trying to draw an outline for one of the instruments for which this model is not ideally suited. There are a couple of common instruments that have outlines which cannot be drawn using this simple five-arc, three-straight-line-segment model. These instruments, the OM and the Maccaferri-style guitars, have a “dropped hips” look to the lower bout that cannot be approximated by a single circular arc (Fig. 2). Fortunately, the lower bouts of these guitars can be accurately drawn with a simple enhancement to the model. The enhancement replaces the single-arc lower bout curve with a compound-radius curve. A compound-radius curve is composed of a series of circular arcs, each tangent to the one succeeding it. Although all manner of complex curves can be built up in this fashion, for the purpose of enhancing the simple guitar body outline model, we really only need to introduce compound-radius curves of two radii. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
Posted on August 1, 2022March 5, 2024 by Dale Phillips Questions: String Tension and Pure Tone Questions: String Tension and Pure Tone by R.M. Mottola Originally published in American Lutherie #98, 2009 See also, Questions: String Tension and Purity of Tone by Alan Carruth Pat Bowen from the Internet asks: A generally accepted fact is that the higher the string tension, the more pure the tone. This causes me grief, since I have to build instruments to support the heaviest strings. Even if I don’t recommend them, someone is going to use them. But is this thing about the high tension and pure tone really true or is it just a folk tale? The Questions Column editor responds: The short answer is yes, it is true, and the short explanation is inharmonicity. The higher the tension, the closer the partials are to true harmonic multiples of the fundamental frequency. On p. 115 of his book Engineering the Guitar — Theory and Practice, Richard Mark French states: “...increasing the radius [of the string] or elastic modulus [i.e., stiffness] makes the deviation from the ideal harmonic series worse, while increasing tension or length makes it better.” This is an interesting topic worthy of an article or at least a longer explanation than I’ve given here, which I hope someone will provide.
Posted on August 21, 2019March 7, 2024 by Dale Phillips Constructing the Middle Eastern Oud, Part One Constructing the Middle Eastern Oud with Peter Kyvelos, Part One by R.M. Mottola previously published in American Lutherie #94, 2008 See also, “Constructing the Middle Eastern Oud, with Peter Kyvelos Part Two” by R.M. Mottola Here in the USA, interest in ethnic music of all sorts has seen an increase in recent years. Probably driven by immigration from many parts of the world and by the rise of so-called world music, this increased popularity manifests itself for us in an increased interest in the stringed instruments used in various ethnic musical styles. For instance, we’ve seen much interest lately in the oud, also commonly spelled ud or ’ud. Starting off with absolutely no knowledge of a subject (as I did with this one), it is probably always a wise first step to consult the experts. Of course, with no knowledge of the subject, even the process of identifying subject-matter expertise is a problem, but I’ve always found that persistent and wide ranging investigation into just who the experts are is a fruitful approach. Eventually it becomes obvious that the same handful of names come up again and again in these queries. During the process of identifying those individuals most likely to be experts on the subject of the oud, it was both unusual and interesting that only one name came up repeatedly. Whether I asked musicians, luthiers, or academics, in this country or in the Middle East, the person that was universally regarded as the foremost expert on the oud was Peter Kyvelos. Working out of his shop Unique Strings in Belmont, Massachusetts, Peter Kyvelos has built close to 200 ouds and other Middle Eastern instruments. The shop, located in a section that is home to many Armenian and other Middle Eastern immigrants, also repairs pretty much all stringed instruments, plucked and bowed, domestic and foreign. But Middle Eastern instruments have been the focus of the shop and of the lutherie of Peter Kyvelos for the last thirty-five years. This dedication has earned Peter the reputation as the expert in this field. It has also earned him a National Heritage Fellowship from the National Endowment for the Arts in 2001. Become A Member to Continue Reading This Article This article is part of our premium web content offered to Guild members. To view this and other web articles, join the Guild of American Luthiers. Members also receive 4 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. If you are already a member, login for access or contact us to setup your account.
