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.
Posted on January 16, 2010February 7, 2024 by Dale Phillips In Memoriam: Jim Mouradian In Memoriam: Jim Mouradian April 2, 1950 – January 24, 2017 by R.M. Mottola Originally published in American Lutherie #130, 2017 Boston area luthier and repairman Jim Mouradian died on January 14, 2017, at the age of sixty-six. With his son Jon, Jim ran the largest guitar repair shop in the New England area. He was also an electric bass player and played for a long time in the R&B band, Ronnie Earle and the Broadcasters. Jim was a masterful repairman who brought the same level of precision and care whether working on the instruments of famous professionals or beginning guitarists. He was probably the most happy and content guy I have ever met. He expressed gratitude daily that he got to do work that he loved for a living, and that he got to work beside his son. His list of clients and list of dear friends were one and the same. He was generous to a fault, particularly with his time. I met him before I had any connection with lutherie. I had brought him a cheap electric bass in need of a part. We talked for a long time — about the bass, people we knew in common, and about hot rods (Jim was an avid fan of muscle cars from the 1960s). Then he rummaged around in a parts box, pulled out the part needed to fix my bass, handed it to me, made sure I understood that he was confident that I could do the repair myself, and sent me on my way, no charge. His death brought forward dozens of similar stories of his generosity. His rates were more than reasonable and he regularly lowered them substantially for folks with limited ability to pay. Photo courtesy of Jon Mouradian In addition to repair work, Jim built a couple of different lines of solidbody electric basses. He got into lutherie in what he has described as “backwards.” His very first lutherie project was a custom electric bass for Chris Squire of the band Yes. This instrument is played in the band’s Owner of a Lonely Heart video. I personally owe Jim a great debt of gratitude for having gotten me started in lutherie. From his initial suggestion that I build an instrument, through his continued advice and guidance and encouragement, he gave me a focus and a purpose at a time of great need in my life. I miss him terribly.
