Posted on July 6, 2026July 6, 2026 by Dale Phillips Fretboard/Top Plate Geometry of the Flattop Guitar Fretboard/Top Plate Geometry of the Flattop Guitar by R.M. Mottola¸ Originally published in American Lutherie #111, 2012 The geometric relationship between the fretboard of the flattop guitar and the top of that instrument is an interesting one, if for no other reason than that a number of the critical dimensions of the instrument such as action and bridge height are affected by it. The geometry of these components is also the source of many technical questions from luthiers attempting to make design departures from conventional instruments, and from those who are simply curious about how all this fits together. This article will discuss the topic using basic examples from conventional instruments. The math will be presented for readers who want to make use of it in their design efforts. Diagrams and textual descriptions are also included, and wherever possible I’ve attempted to discuss the practical ramifications of some typical approaches to this aspect of guitar design. This latter part is generally limited to the basic mechanics of how the parts of the instrument fit together. Although it could be fruitful to widen the scope here to include discussion of general mechanics and acoustics of the instrument, I am not dwelling much in these areas. There is enough to cover just discussing the geometry and assembly considerations. To begin, I’d like to introduce some basic concepts and terminology. Some of these concepts are both generally understood and are described using standard terminology. Terms like bridge height, action, and neck angle are familiar, but let me quickly define each of these as they are used in this article. Bridge height is the nominal height of the bridge from the top of the guitar to the top of the saddle at the instrument’s centerline. Neck angle is the angle between the nominal plane of the top and that of the surface of the neck shaft that contacts the underside of the fingerboard. A positive neck angle means the neck is angled toward the back of the body. Action is the height of the strings above the fret crowns. More specifically (as used here), it is the height of the nominal string-bottom plane over the nominal fret-crown plane. 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 June 16, 2026June 16, 2026 by Dale Phillips An Enhancement to the Outside Mold An Enhancement to the Outside Mold by R.M. Mottola Originally published in American Lutherie #79, 2004 and Big Red Book of American Lutherie Volume Seven, 2015 The outside mold is a useful tool for side bending. If the side slat is bent to roughly the ultimate shape of the side and then clamped into the mold while still hot and damp, the slat will conform to the shape of the mold while it cools and dries. This works pretty well for the following reason. If you make a bend in wood, as it cools and dries it tends to revert to its original shape. This springback phenomenon causes all manner of grief with some approaches to side bending, but it can be used to advantage when using a mold. Sides can generally be over bent slightly and then clamped into the mold, where they will relax into the shape of the mold as they cool and dry. So for the most part, when using an outside mold you can just bend the wood to only the roughest approximation of the final shape and let the mold and springback take care of the rest. This technique works great for all of the areas where the mold is on the outside of the curve, but doesn’t work at all where the mold is on the inside of the curve, such as at the waist bends in an outside mold. That’s because springback makes the bent sides pull away from the mold at the waist as the wood cools and dries. 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 June 12, 2026June 12, 2026 by Dale Phillips The “Mysteries” of Panormo The “Mysteries” of Panormo by R.M. Mottola Originally published in American Lutherie #132, 2017 One of the classics of lutherie literature is the book, The “Secrets” of Stradivari by violin historian Simone F. Sacconi. This thick book contains much detailed information on the instruments of the Cremonese master violin maker, enough so that, for some readers, what may have once been considered to be true secrets of design and construction are revealed. The title of this article is a takeoff on that of Sacconi’s book. Sacconi spent a lifetime researching the instruments detailed in his tome and so the information imparted there can be considered to be definitive. Having recently completed a single long construction project of a replica instrument by 19th century guitar maker Louis Panormo (Photo 1), I am in nowhere near a position to assume expertise in the “secrets” of Panormo’s guitars. But that project did introduce me to a number of features typical of instruments of that time and, in particular, of the instruments of that maker. 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 May 20, 2026May 20, 2026 by Dale Phillips Testing Threaded Inserts Testing Threaded Inserts by R.M. Mottola Originally published in American Lutherie #101, 2010 Threaded inserts are used in bolt-on acoustic guitar necks, in the style of neck joint popularized by Taylor guitars. An example of a butt-joint neck heel with threaded inserts is shown in Photo 1. I have posted instructions for constructing this style of neck joint on my lutherie info website and not long ago received an e‑mail message from someone taking me to task for the type of threaded inserts specified there. For years I have used self-tapping machine screw threaded inserts and have had good success. But the writer pointed out that these inserts were “not for wood” and so I thought a test of these and other types of threaded inserts would be an appropriate thing to do. There may be better inserts than the ones I was using, and testing is the only way to find out. What I wanted to discover was how strong the hold of the insert was on the wood into which it is inserted. 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 April 30, 2026April 30, 2026 by Dale Phillips Product Reviews: Garrett Wade Versatile Vise Product Reviews: Garrett Wade Versatile Vise by R.M. Mottola Originally published in American Lutherie #119, 2014 Garrett Wade Versatile Vise #05R10.10, $84.70 garrettwade.com The item reviewed in the following paragraphs was provided to American Lutherie for review. A draft of this review was sent to the supplier prior to publication so that any factual errors in the review could be corrected. A long time ago, before I started doing any serious woodworking, I had the pleasure of visiting the shop of a local woodcarver. In addition to a bewildering collection of gouges and mallets, he had a cool work-holding vise which could be positioned to hold the work in just about any position. I had forgotten most of the details of that visit soon after, but when it came time to begin equipping my own lutherie shop, I remembered that vise and considered it would be just the thing as the primary work-holding device. With only a description of what it could do, I rooted around for information and finally found that it was called a Versa Vise and was American made. That was the good news. 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.
