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, 2022February 29, 2024 by Dale Phillips Transducers Transducers by Reagan Cole Originally published as Guild of American Luthiers Data Sheet #54, 1977 The purpose of this particular article is to project one man’s opinion about the theoretical whys and wherefores of the transducer for acoustic instruments. This is not a consumer’s report analysis of commercially available products. Anyone interested in this information may consult the series which is currently running in Mugwumps Instrument Herald. A full market report and commentary has been promised. I have never had the money to run out and A-B all the stuff that crops up in the pages of Guitar Player; anyway, I have never used any of the commercial units since I build my own systems. There seems to be several major camps regarding the amplification of acoustic instruments. These I would categorise as follows: (1) Only microphones should be used. These devices are, after all, an electrical analogue to the human ear, so if the mike is good all will be well. Absolutely nothing should be attached to an existing acoustic instrument. (2) Transducers are a necessary evil. They do allow musicians playing acoustic instruments to compete in an electric or an electronic ensemble. At any rate, if they are used they should be easily removable, leaving no trace. (3) The acoustic-electric is yet another evolutionary phase. The performance of the instrument transducer system is of paramount importance; It may be necessary to modify the instrument or even to design a new type for acoustic-electric use. I don’t believe that there are grounds for a serious feud lurking in any of these arguments; all are correct from their own frames of reference. 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, 2022February 2, 2024 by Dale Phillips Conical Radius Fretboard Formula Conical Radius Fretboard Formula by Elaine Hartstein Originally published in American Lutherie #34, 1993 and Big Red Book of American Lutherie Volume Three, 2004 As a follow-up to Tim Earls’ article “In Search of the Perfect Cone” in American Lutherie #30, I’ve come up with a formula for finding the hypothetically-ideal radius for the fingerboard at any distance from the nut. Since a set of nonparallel strings cannot lie flat on a cylindrical fretboard, we wish to discover the geometry of the cone described by the strings. As Tim Olsen suggested, the outside strings (as opposed to the edges of the fingerboard) should define the cone. The cone defined by the fingerboard edge would give results with a smaller radius. 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: Significance of Q Questions: Significance of Q by Brian Burns Originally published in American Lutherie #86, 2006 John Belluci of Baltimore, MD asks: Please explain what “Q” is when referring to wood or instruments. The definition I’ve seen is, “internal damping.” Brian Burns of Fort Bragg, CA responds: “Q” is one of the basic qualities of the materials we use to make stringed instruments. The traditional low-tech Q test is to listen to the tap tone of a piece of wood and hear how long it takes for the sound to die away. The longer the tap tone lasts, the higher the Q, and the greater the potential of that piece of wood to make a loud instrument with long sustain. The design and construction of the instrument of course determine the ultimate result; the Q test just gives you an idea of the potential of that particular piece of wood. 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.
