Posted on June 30, 2024May 14, 2025 by Dale Phillips Mechanical Compliance for Soundboard Optimization Mechanical Compliance for Soundboard Optimization by David Hurd from his 2006 GAL Convention workshop Originally published in American Lutherie #90, 2007 People say, “You’ve got to make fifty or a hundred guitars before you get it right.” That makes me crazy. I feel that if you can do the carpentry of putting an instrument together and have idea of what it should look like, you can get 80% or 90% of the way there in terms of top optimization with a mechanical compliance approach. I build many sizes of guitars and ukuleles using different top woods. I have developed an easy method of testing the compliance of a top, that is, how far it flexes under a given force, with a simple fixture. Being able to measure and compare the compliance values has proved to be a very useful thing in optimizing these soundboards for the best sound and stability when I graduate the edges of the tops and carve the braces. After building and measuring many instruments, I have developed a mathematical model that does a very good job of estimating what the target compliance measurements should be for a given instrument size and string tension. I have integrated the model into a spreadsheet which you can use by plugging in just a few simple measurements. 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. Members also receive 3 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on June 30, 2024May 14, 2025 by Dale Phillips The MacRostie Mandolin Deflection Jig The MacRostie Mandolin Deflection Jig by Don MacRostie from his 2004 GAL Convention workshop Originally published in American Lutherie #94, 2008 The mandolin world is small enough that if you’re even thinking about building one, you probably already know who Don MacRostie is. Don is an inventor, and he’s done more for Stewart-MacDonald than we will ever hear about. He’s been making Red Diamond mandolins for two decades now. At the 2004 GAL Convention Don discussed one of his research tools and told us how he applies it to his construction process to make the sound of his finished instruments more consistent and predictable. — John Calkin At the GAL Convention in 2001, Charles Fox floated the idea of teaching a mandolin building class at his American School of Lutherie. As a result, I taught a two week class, building A-style mandolins from scratch. The only thing we started with was thickly precarved oversize tops and backs. Everything else we made totally from scratch. It was a great experience. Peggy Stuart, a student in the class, documented the experience in a series of American Lutherie articles (AL#75–AL#79). Tim Olsen asked me to demonstrate and explain the plate-deflection machine we used in the class at this convention, so that’s why we’re all here. 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. Members also receive 3 annual issues of American Lutherie and get discounts on products. For details, visit the membership page. MEMBERS: login for access or contact us to setup your account.
Posted on April 7, 2022May 13, 2025 by Dale Phillips Violin Setups, Part One Violin Setups, Part One by Michael Darnton from his 1990 GAL Convention lecture Originally published in American Lutherie #35, 1993 and Big Red Book of American Lutherie Volume Three, 2004 See also, Violin Setups, Part Two by Michael Darnton Setups represent one of the most important aspects of violin work. They are the most changeable part of a violin and can make the difference between a customer liking or hating a violin. People who do setups for a living in large shops do a lot of them — countless numbers of bridges, pegs, posts, and nuts. If you’re making one or two or twenty instruments a year you’re not going to be doing many setups. For the people who do those things everyday, it’s a very specialized art and they have very rigorous standards. With that in mind I’m going to try to communicate to you some of those standards, along with some actual “how-to” hints. Tools A bench hook (Photo 1) is simply a piece of wood that has a strip nailed to the bottom on one end and a strip nailed to the top on the other end. It hooks over the front edge of the bench and gives a stop to work against. On the under side of my bench hook I’ve glued a piece of sandpaper (Photo 2). If a tiny, thin piece of wood needs to be planed thinner, I flip over the bench hook and use the sandpaper as a traction area. 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 October 25, 2021May 14, 2025 by Dale Phillips Geometric Design of the Stradivari Model G Violin, Part One: Mold and Template Geometric Design of the Stradivari Model G Violin, Part One: Mold and Template by Robert J. Spear Originally published in American Lutherie #93, 2008 see also, Geometric Design of the Stradivari Model G Violin, Part Two: f-holes by Robert J. Spear Geometric Design of the Stradivari Model G Violin, Part Three: The Scroll by Robert J. Spear I have little doubt that artists, artisans, and architects of the Renaissance and Baroque used some system of guidance for their drawings that was based on the knowledge of geometry and the use of straightedge and divider. I began my drawing adventure almost five years ago by following the guidelines for the geometric design of the Model G in Sacconi’s book and soon discovered errors. Even so, I was convinced that it would be worthwhile to use a classical Cremonese approach based on geometry because I wanted to see if I could integrate it with Hutchins and Schelleng’s scaling theories used for the New Violin Family. While the acoustical aspects of the exercise are not germane here, I worked to realize a design system that would essentially produce a second generation of octet instruments close to a classical Cremonese violin in the style of the Model G Stradivari. My goal was to impart a greater uniformity to the octet family’s models, but to keep this article within bounds I have confined my remarks to the violin. There are those who question whether geometric design really played an important role in violin design and suggest that the model outline could be designed freehand. Others allow that some sort of geometrical or proportion scheme was used, but that it was not based on the golden section. A few ask why one can’t just get a good photo of a good model and enlarge or reduce it at the local copy center. You can (and I did at first), but because strange things start to happen in the larger and smaller instruments during the scaling process, straight scaling does not hold up. Still others, including Sacconi, stress that the eye was the final arbiter of any design, no matter how it was derived. I will attempt to address all of these points in this series of articles. 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 April 12, 2021May 16, 2025 by Dale Phillips Free Plate Tuning, Part One: Theory Free Plate Tuning, Part One: Theory by Alan Carruth Originally published in American Lutherie #28, 1991 and Big Red Book of American Lutherie Volume 3, 2004 See also, Free Plate Tuning, Part Two: Violins by Alan Carruth Free Plate Tuning, Part Three: Guitars by Alan Carruth I started learning free plate tuning on violins and violas more than ten years ago from Carleen Hutchins. For those who have not had the pleasure of her acquaintance, Carleen is one of the founders of the Catgut Acoustical Society and its permanent secretary. She is an able scientist, a great teacher, a fine luthier, and a self-confessed mediocre violist. While working with physicist Frederick Saunders almost thirty years ago she helped rediscover and update the old Chladni method of visualizing the vibrations of plates. Her subsequent research, using Chladni patterns as a window into the differences between good and poor violins earned her a silver medal from the Acoustical Society of America. Violin makers have traditionally used some variant of “tap tone” tuning to guide them in working out the final graduations of the top and back plates. Although the technique seems simple and organic on the face of it, it is in fact very complex. It takes a long time, as well as a good ear and a lot of talent, to learn to tune plates by tap tone. Even those who are good at it don’t always succeed. Felix Savart, back in the 19th century, tried to adapt Chladni’s method to research on violin acoustics, but the technology wasn’t there. Now we have the means, and as we gain more understanding of how the instruments work, we also gain more control over the sound. And it doesn’t only work on violins. Fred Dickens, Graham Caldersmith, and Gila Eban have all done major work in applying the principles of violin acoustics to guitar construction. Of course, there are differences and it takes time and effort to sort them out, but physics is physics, or, as a friend of mine said, “it all comes down to F=mA in the end.” I have found these techniques to be useful, and sharing useful techniques is what the Guild is all about. 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.
