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Geometric Design of the Stradivari Model G Violin, Part Two: f-Holes

Geometric Design of the Stradivari Model G Violin, Part Two: f-Holes

with Robert J. Spear

Originally published in American Lutherie #94, 2008

see also,
Geometric Design of the Stradivari Model G Violin, Part One: Mold and Template by Robert J. Spear
Geometric Design of the Stradivari Model G Violin, Part Three: The Scroll by Robert J. Spear



The Cremonese design for the f-holes of a violin, at first glance, would appear to be based on the same design philosophy as the body and to make extensive use of the golden section. A. Thomas King, in his article “The Cremonese System for Positioning the f-Holes” in The Strad, shows rather convincingly that golden-section divisions based on the distance between the pins on the body was employed to fix the location of the f-hole eyes, which further reinforces this idea. However, when it comes to f-holes, I would like to suggest that there are a couple of additional jokers in the deck. First, the late Cremonese f-hole is derived from an earlier system of design, and some of the important parts of the predecessor system remain in use; second, an entirely different modulus is used for the f-holes than for the body; and, third, little is based on the golden section.

The Forma G violin, upon which my model is based, is not quite the longest violin Stradivari ever made, but it is the widest. The most notable increase in width is in the center bout, which has another direct impact on the design of the f-hole and its placement. King notes that there is a general method for most Cremonese violins and a specialized adaptation for Stradivari violins. King explained the rather unintuitive step of taking the golden section of the distance between the locating pins in the top as the modulus for positioning the f-holes. I have used his approach here because it has many good points of correlation, and because I found an additional correlation that has convinced me even further that his hypothesis is correct.

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Violin Ribs/Latent Tension

Violin Ribs/Latent Tension

by John Meng

Originally published in Guild of American Luthiers Data Sheet #287, 1984 and Big Red Book of American Lutherie Volume One, 2000



Bending Ribs

When wood is bent, the length of the outer surface increases or the length of the inner surface decreases; or most likely some combination of the two occurs. In soft woods, the fibers stretch and compress more easily than they do in hard woods, so soft woods can successfully be bent to smaller radii than can hard woods before the wood fractures.

Thin maple strips used to form violin ribs must be bent to small radii at the corners. Maple being a hard wood, there is a tendency for fibers along the inner surface to strongly resist compression.

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Finite Element Simulation of Guitar Top Vibration

Finite Element Simulation of Guitar Top Vibration

by Phil Banks

Originally published in American Lutherie #18, 1989



The use of engineering finite element analysis software to determine modes and natural resonant frequencies of a guitar top can be a useful (albeit lengthy) process which, if used judiciously, can yield useful information to the guitar maker.

As a graduate mechanical engineer and a guitar maker, I’ve always been interested in marrying the discipline of the luthier’s craft with that of science. I got that chance last year at the University of Sydney. While working as a programmer developing a Finite Element package, I was asked to produce a demonstration of the program’s capabilities. I decided to analyze a guitar top.

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Lutherie: Art or Science?

Lutherie: Art or Science?

by R.E. Bruné

Originally published in American Lutherie #1, 1985



Aside from the eternal “How do you bent the sides” question asked by non-makers, the most frequent point of curiosity seems to be that of other makers: “What do you think of the Kasha guitar?” I am somewhat surprised at this.

Firstly, it doesn’t really matter what I think of the Kasha model. I don’t build it, and I would think this fact says enough. The second point is that the Kasha model and theories have been around for enough years (nearly twenty if I’m correct) that, were there merit in the model, it would have been almost universally adopted by makers and players by now. It took less than twenty years for the conservative makers of Spain to adopt the design ideas of Torres, for by the time of his death just before the turn of this century, nearly every Spanish maker with the exception of José Ramírez I was using his model. The reason for this nearly overnight conversion is obvious; the models of Torres were clearly superior to anything else available, and the musicians quickly accepted them. In fact, the makers who didn’t adopt his patterns went out of business.

In contrast, one does not see musicians today playing the Kasha model. I know of no professional classical guitarists playing them, and in the nearly twenty years I have been involved in the guitar world, I have never been to a concert where a Kasha model guitar was played. Yet it seems there has hardly been an issue of the G.A.L. Quarterly without some article or reference to the Kasha model as if it were definitive, and desirable.

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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.

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