Posted on September 2, 2022May 22, 2025 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 July 1, 2022May 28, 2025 by Dale Phillips The Right CAD Curve The Right CAD Curve Bezier Curves, Not Splines, Are Truly Smooth Curves by David Golber Originally published in American Lutherie #72, 2002 and Big Red Book of American Lutherie Volume Six, 2013 Bezier curves, as opposed to splines, have been known since the 1970s. They are supported by AutoCAD and AutoCAD LT, but not by many other popular CAD packages. What are they, and why do we care? It’s easiest to start with an example. Fig. 1 shows the outline of a harpsichord. Look at the curved side. The coordinates of the points are from Kielklaviere,1 which describes the curved side of the instrument by listing the coordinates of points along the side. The curve in Fig. 1 is the ordinary spline through those points. Fig. 2 shows that one of the points is erroneous enough that it clearly makes the curve bumpy. 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 July 1, 2022May 27, 2025 by Dale Phillips A Different Way of Defining Body Shapes A Different Way of Defining Body Shapes by Mark French Originally published in American Lutherie #88, 2006 As I look through American Lutherie, I am struck by the advances in the tools some of us use to make our instruments. While there will always be the traditionalists who do most of their work by hand, more of us are using computer-controlled machines to make jigs or parts. Even the musical instrument lab here at Purdue (www.metalsound.org) has its own CNC router. Large manufacturers like Taylor Guitars use CNC equipment for the majority of their building operations. An obvious advantage of all this cool stuff is that parts can be made much more precisely. However, the parts can only be as precise as the instructions that are driving the machines. Look through your favorite book on guitar making and find the section on laying out the body shape. Even the best books, like Making an Archtop Guitar by Benedetto and Guitarmaking: Tradition and Technology by Cumpiano and Natelson, offer only the most basic description of the shape. It’s pretty common for the instructions to start with something like “draw a straight line on a sheet of brown wrapping paper to use as a centerline.” 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 11, 2021May 30, 2025 by Dale Phillips Calculating Fret Scales Calculating Fret Scales by Bob Petrulis Originally published in Guild of American Luthiers Data Sheet #4, 1974 and Lutherie Woods and Steel String Guitars, 1998 When many of us were starting out, calculating fret scales seemed an arcane and mysterious art, something known to a few high priests of the craft. As kids, we copied scales from existing guitars, or got a list of measurements from a book or by pestering an instrument maker. We did this partly because we knew little of the physics of music, and partly because, back in the dark ages, calculators and computers were not easily available to teenage kids trying to make musical instruments in their basements or in wood shop at school. This article provides the information you need to calculate any fret scale in any unit of measurement you wish. I am assuming you are calculating a chromatic scale, twelve notes to the octave. If you need to calculate a scale, say, for a dulcimer, I recommend that you calculate the entire fret scale, and then remove the unneeded frets from your listing. 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 10, 2010May 26, 2025 by Dale Phillips Letter: First Guitar Letter: First Guitar by Gretchen Weeks Brough Originally published in American Lutherie #45, 1996 Dear GAL, I am a new member, in the process of making my first guitar — a flattop acoustic cutaway. I became interested in lutherie when my husband needed a quality acoustic guitar and we couldn’t afford what he wanted. I asked a local luthier about learning the art, and his recommendation was to get all the books and videos I could find, and then buy a kit from Martin as a first project. This, we could afford! In AL#43, a letter from Mr. Rick Topf mentions computer aided design (CAD), and wondering if there would be any interest in drawings done in AutoCAD format. There certainly is! I am, by trade, a freelance computer drafter, working in AutoCAD format. Not only would I be interested in drawings anyone else has done in AutoCAD, I would be happy to offer my services to anyone who wants their drawings done in AutoCAD. 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.
