Posted on October 21, 2026November 4, 2026 by Dale Phillips What Happens If I Make It Bigger? What Happens If I Make It Bigger? Rules of Thumb for Approximating Changes in the Size of Braces, Tops, and Strings by Jon Sevy Originally published in American Lutherie #73, 2003 and Big Red Book of American Lutherie, Volume Seven, 2015 While gluing top braces on a guitar top, I was led to the question: How much do small changes in dimensions of elements used in our guitars affect their function? I was gluing on the small support braces that run from the X brace to the edge of the top to provide extra support against the tension of the strings on the bridge, and didn’t have any braces made up of exactly the right cross-section size. For the model I was constructing, I use braces that are 1/4˝ W × 7/16˝ H for these small support braces, but the only brace stock I had at hand was 5/16˝ W × 3/8˝ H. Making up new brace stock is a bit less trivial than it might seem. I use a top that is slightly arched, and consequently, I arch the gluing surfaces of all the braces. To accomplish this, I use a jig that I read about some time back in an article by Dana Bourgeois in American Lutherie #6. A brace is flexed and clamped into a curved (bent) configuration and planed flat; when released from the jig, the brace springs back and the flat-planed surface becomes a beautiful smooth convex curve matching the radius of the top. There’s drawing of it in The Big Red Book of American Lutherie Volume One, p. 177. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on October 20, 2026November 2, 2026 by Dale Phillips Forces on Archtop Guitars Forces on Archtop Guitars by Franz Elferink Originally published in American Lutherie #74, 2003 and Big Red Book of American Lutherie Volume Seven, 2015 The choice of strings among jazz players ranges from ultra-light, low-tension sets (.009˝–.046˝) up to the heavy, high-tension acoustic big-band setup (.014˝–.060˝). String tension deforms an archtop instrument in a number of ways. Extreme deformation can destroy the instrument. Common problems that are related to string tension are collapsed tops, neck heels which are pulled out of the body, and fingerboard extension “pop up.” String Tension. A number of factors influence string tension including the density of the material(s) from which the string is made. The lighter the material of the string, the lower the string tension for a given frequency and vibrating length. If a steel string was replaced with a nylon string of the same diameter and tuned to the same pitch, its tension would be a small fraction of that of the original steel string. In real-world string sets, nylon strings exert approximately half the tension of steel strings, even though they are of considerably greater diameter. The following equation can be used to calculate string tension. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on October 1, 2026October 27, 2026 by Dale Phillips Rib Depth of Guitars with Spherically Domed Plates Rib Depth of Guitars with Spherically Domed Plates A Survey of Some Published Methods for Shaping the Ribs of Flattop Guitars, with Some Elaboration and Some Additional Information by R.M. Mottola Originally published in American Lutherie #84, 2005 and Big Red Book of American Lutherie Volume Seven, 2015 Modern flattop guitars generally do not have flat tops (or backs) at all. Instead, the plates of these instruments are generally forced into spherically domed shapes. The doming is accomplished using arched braces glued to the plate while it is pressed into a dished assembly board. Once the glue hardens, the plate permanently assumes the domed shape. The radius of the dome is generally quite large, typically ranging from 12´–30´, so the doming effect is slight. Still, this doming means the edges of the plate are not constrained to a single horizontal plane, and this means that the ribs of an instrument using this style of plate must vary in depth in order to uniformly contact the plate edges. For those unfamiliar with this style of construction, the issue can be imagined by considering a round, spherically domed plate sitting on a table. The edge all the way around the plate will contact the table top. If the round plate is now cut into the shape of a guitar plate and that plate is set on the table, the edge will not contact the table top all the way around, as shown in Fig. 1. While points at the neck and tail block positions will touch the table, the rest of the edge will vary in distance above the table top. Again, the ribs of a guitar with such a plate would have to vary in depth if they were to continuously contact the plate edge, without gaps. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on September 25, 2026September 25, 2026 by Dale Phillips The Charles Fox Guitar-Building Method, Part Two The Charles Fox Guitar-Building Method, Part Two by Mark French Originally published in American Lutherie #140, 2020 See also, A Guitar Is Born: Attending Charles Fox’s Hands-On Guitar Making Course by Mark French The Charles Fox Guitar-Building Method, Part One by Mark French The Charles Fox Guitar-Building Method, Part Three by Mark French The Charles Fox Guitar-Building Method, Part Four by Mark French The Charles Fox Guitar-Building Method, Part Five by Mark French The Charles Fox Guitar-Building Method, Part Six by Mark French There are four major subassemblies in Charles’ guitar design. The separately completed rim, soundboard, and back are assembled to create the body, to which the completed neck is then fitted and attached. Given that the design process has highlighted and resolved all their relationships, they can each be considered individually, and created either serially, in any sequence, or simultaneously. Starting the Neck At first glance, Charles’ neck follows a fairly standard design, but it incorporates features that make it work better. One characteristic of Charles’ instruments is that many features and dimensions are shared across different body shapes (“Production Techniques for the Custom Luthier,” AL#110). One of these is the neck. Since most of Charles’ instruments share the same 25.5˝ scale, they can use the same 12-fret or 14-fret necks. The only visible difference is their heel depths, as shown in Photo 1. Even then, there are only two different depths. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on August 14, 2026August 14, 2026 by Dale Phillips An Optical Sensor For Detecting String Motion An Optical Sensor For Detecting String Motion by Mark French Originally published in American Lutherie #106, 2011 For luthiers who want to make accurate dynamic measurements on their instruments, it is a challenge to achieve precision for a cost that stays below the pain threshold. Commercial test equipment is readily available, but the prices can be breathtakingly high. There is always eBay, but the selection isn’t always there and the condition of the equipment can be a little sketchy. That leaves the option of making test equipment for yourself. Since the average luthier is constantly making nifty jigs and fixtures, it makes sense to offer a very inexpensive DIY option. I needed a pickup for some projects that require measuring the first twenty or thirty harmonic frequencies of a vibrating string. I’m worried that the pickup response at high frequencies might drop off. All pickups have a window over which they are sensitive, and that window needs to be very short in order to observe the really high harmonics. Single-coil pickups have a shorter window than humbuckers. This makes them more sensitive to higher frequencies and is at least part of the reason that they can sound “brighter.” Also, the presence of a strong magnetic field from a coil pickup might affect the motion of the string. In order to affect the string as little as possible, I wanted to make an optical sensor. Become A Member to Continue Reading This Article This article is part of the Articles Online featured on our website for Guild members. To view this and other web articles, join the Guild of American Luthiers. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
