Tag Archives: French¸ Mark

Mark French

Twenty-year GAL member Mark French has been making guitars since about 1990. He is a professor at Purdue, where he runs the Guitar Lab. He was trained as an aerospace engineer and worked several different places before fetching up at Purdue in 2004. In addition to making his own instruments, he teaches a guitar design and manufacturing class and writes books. So far, he’s done three books on guitars and one on nonlinear optimization. Surprisingly, the movie rights for all four are still available.

▪ bio current as of 2024

Changing Guitar-Body Resonant Frequencies

2024
AL#152 p.52               
Devon Pessler   Alyssa Fernandez   Mark French                                                                                   

▪ A lot of people have a rough idea of how it would affect the sound of a flattop guitar to make the sides deeper, or to make the soundhole smaller. But now a college professor and two students have built the test apparatus and quantified the question. Read this article and see if you guessed right.

Measuring the Breaking Strength of Steel Guitar Strings

2024
AL#151 p.58               
Mark French                                                                                           

▪ It’s amazing what you can do with a smart phone these days. Think you would need an anvil, a block-and-tackle, and a bathrom scale to measure the breaking strength of a guitar string? Nope. There’s an app for that. Mentions Fine Chromatic Tuner.

Let’s Catch Up With Richard Bruné and Marshall Bruné

2023
AL#150 p.16               
Mark French                                                                                           

▪ Richard “R.E.” Bruné was in the GAL’s very first cohort and was an author and convention presenter from the very beginning. We’ve visited him a couple of times over the decades. His son Marshall was born into the business, and into the Guild. Together they run a large workshop and epicenter of classical guitar making, scholarship restoration, appreciation, and dealing.

Reducing Frequency Error in Electric Guitars

2023
AL#150 p.38               
Mark French   Devon Pessler   Alyssa Fernandez                                                                                   

▪ Ya talk about rabbit holes. Research into guitar intonation just gets deeper and deeper. This article homes in on individual string compensation at the nut, plus small adjustments to the position of the 1st and 2nd frets. Industrial strength data collection. Heed the eggheads.

Using Soundhole Inserts to Vary the Lower Resonant Frequencies of an Acoustic Guitar

2023
AL#149 p.50               
Mark French   Eddy Efendy                                                                                       

▪ Putting a tube in the port of a loudspeaker box changes the lower resonances. Makers of classical guitars have known about that for a century and a half. They call that tube a tornavoz. French and Efendy give us the math on how it works.

An Easy Fretboard-Tapering Jig

2023
AL#149 p.62               
Mark French                                                                                           

▪ This super-simple table saw jig is a strip of plywood with two alignment pins in drilled holes. Easy to make and to use.

Helmholtz Resonance in Acoustic Guitars

2023
AL#148 p.28               
Mark French                                                                                           

▪ If you are like me, you probably think you know what the Helmholtz resonance of a flattop guitar is. And like me, you may be exactly wrong. Turns out it is the note that you don’t hear. Mentions Fender Acoustasonic Stratocaster, tornavoz.

It Worked for Me: Humidifier from Ball-Point Pen

2022
AL#146 p.70               
Mark French                                                                                           

▪ Make a quick and dirty guitar humidifier out of materials you may actually have in your pocket, like a ball point pen and some lint. Kidding about the lint.

Measuring Mechanical Properties of Neck Blanks

2022
AL#146 p.44               
Mark French   Alyssa Fernandez                                                                                       

▪ How stiff is that neck blank? You could cut all your blanks to the same dimensions and then set up a rig with a hanging weight to measure deflection and such. But hey, got a smart phone? It can listen while you tap on a bunch of neck blanks, and then tell you how stiff each one is.

The Musical Instrument Museum — A Must-See for Luthiers

2022
AL#145 p.32               
Mark French                                                                                           

▪ Frequent author Mark French spends a lot of time in the physics lab and the workshop. But here he emerges, blinking, into the Arizona sunshine to visit a fabulous musical instrument museum. In fact, it’s The Musical Instrument Museum.

The Charles Fox Guitar-Building Method, Part Six

2021
AL#144 p.44               
Mark French                                                                                           

▪ In this concluding episode of the series, the neck is fretted and the frets are filed and polished. Threaded inserts are installed in the heel and the neck is attached. Finally, the bridge is glued on, the nut is set in position, and the guitar is strung and set up.

Guitar Making as a Teaching Tool

2021
AL#144 p.56               
Debbie French   Mark French                                                                                       

▪ There is a national movement to teach teachers how to teach STEM subjects (science, technology, engineering, and math) to high-school students; you have them make guitars. Turns out people think it’s fun to make guitars. Who knew?

Letter: Response to: Seeking plans for Scaled-Down Classical Guitars

2021
AL#144 p.4               
Mark French                                                                                           

▪ Berge seeks plans for small classical guitars, suitable for kids. Readers suggest he look at commercially available student models and draw his own plans. Hope that was helpful.

Letter: Charles Fox Neck Angle Sander

2021
AL#143 p.3               
Mark French                                                                                           

▪ Steve asks for more specific info on the device seen on the cover of AL#141. It is a sander which refines the plane of the top at the neck joint so that the angle of the neck will give the correct height of the bridge saddle. Mark answers and provides explanatory photos.

Letter: Sealer for MDF Jigs

2021
AL#143 p.5               
Mark French                                                                                           

▪ Leo asks what sealer Charles Fox uses on his MDF jigs, noting that they look great in the Guild’s Fox Method series and that Charles says he has been using some of them for twenty years. Author Mark French responds with info straight from Charles. He also comments on the use of MDF as wasteboards for vacuum hold-downs in CNC work.

The Charles Fox Guitar-Building Method, Part Five

2021
AL#143 p.22               
Mark French   Charles Fox                                                                                       

▪ In this article the fretboard is slotted, crowned, and glued to the neck. The neck is then shaped.

Measuring Resonant Frequencies of an Acoustic Guitar

2021
AL#143 p.48               
Mark French                                                                                           

▪ Here’s how to quickly make a frequency-response curve of a guitar on your bench, using a handheld digital recorder and free software. Not cheap and easy enough for you? The author goes on to tell you how to do the whole thing on a smart phone. Mentions Spectroid, MATLAB, and Audacity.

The Charles Fox Guitar-Building Method, Part Four

2021
AL#142 p.14               
Mark French   Charles Fox                                                                                       

▪ In this article the peg head is shaped and drilled, the neck shaft is slotted for the truss rod, the heel is formed, and the neck is fitted to the body.

The $75 Guitar Challenge

2021
AL#142 p.40               
Doug Hunt   Mark French                                                                                       

▪ Two luthiers dare each other to make a useful guitar for a total investment of $75 each. One makes a flattop, the other a solid body. There are rules, and rules are meant to be broken.

The Charles Fox Guitar-Building Method, Part Three

2020
AL#141 p.7               
Charles Fox   Mark French                                                                                       

▪ In this episode of the landmark series, the back and top plates are braced and glued to the rim to form the body of the guitar. The body is then bound and purfled using Fox’ distinctive method of fitting everything dry, taping it in place, and running superglue into the seams.

Guitar Making with an X-Carve CNC Router

2020
AL#141 p.50               
Mark French                                                                                           

▪ Here come the robots. Although CNC routers are not yet at the Jetsons stage, we are far beyond the days when computer-driven tools were only in luthiers’ dreams, not their workshops. Mark French brings us up to date as he selects and installs an inexpensive machine in his home shop.

The Charles Fox Guitar-Building Method, Part Two

2020
AL#140 p.20               
Mark French   Charles Fox                                                                                       

▪ Building a Charles Fox guitar reveals the beautifully developed interdependence between the design and the process. In this episode we rough out the neck, work with the unusual neck block and the distinctive two-part lining, and then brace the top and back plates.

The Charles Fox Guitar-Building Method, Part One

2020
AL#139 p.26               
Mark French   Charles Fox                                                                                       

▪ If, some day, there is a Mt. Rushmore for the American Lutherie Boom, the ruggedly handsome face of Charles Fox will be boldly chisled in a place of honor. For over half a century he has led the way as developer and teacher of guitar-making methods and tooling. He is also a thoughtful and articulate philosopher of the craft, whose words will inspire luthiers yet unborn. Here’s the first in a series of four articles which will cover his process, and his thinking behind it, in detail.

Flamenco on the Front Range

2019
AL#138 p.20               
Mark French                                                                                           

▪ Author Mark French is walking the lutherie path in the reverse direction of many makers. As a physics prof trained in the crazy magic of CNC and industrial robot processes, he had made a lot of guitars before he did much in the way of traditional low-tech hand-tool work. As part of an intensive effort to fill in those gaps, he attended an eight-day course at Robbie O’Brien’s shop in Colorado to make a flamenco guitar with Spanish luthier and licensed bloodless toreador Paco Chorobo. O’Brien went to Spain and visited Paco’s shop in 2015. Read all about it in AL124.

CNC Routers for Luthiers

2019
AL#137 p.16               
Mark French                                                                                           

▪ CNC Routers are kinda like computers. Once they were huge and cost more than a house. Therefore they were mostly in the domain of large corporations. Now they are far smaller, and the price tag is closer to a few months’ rent. Therefore they will be ubiquitous. This article lets you know what it would take to get on the bus. Mentions Easel; VCarve; BobCAD; Draftsight; AutoCAD; SketchUp; Fusion 360; Rhino3D.

Mechanical Impedance

2019
AL#136 p.20               
Mark French                                                                                           

▪ We all know what “impedance” is, right? It’s that stuff… the force that… well, what is it really? Turns out it’s something like pushing a kid on a swing at the wrong time. And it has a lot to do with the resonances of acoustic instruments, which has a lot to do with how they sound. Anyway, in this largely math-free presentation, Professor Mark gives us the scoop.

A Guitar Is Born: Attending Charles Fox’s Hands-On Guitar Making Course

2019
AL#136 p.54               
Mark French                                                                                           

▪ Author Mark French has made a lot of guitars over the years, but when he wanted to up his game he attended an intensive two-week course by the dean of all American lutherie teachers, Charles Fox. Four students each built a guitar in the white from scratch and strung it up.

Guitar Making: The Luthier’s Bench and the Factory

2018
AL#135 p.54               
Mark French                                                                                           

▪ Lutherie is changing. Digital tools are transforming factories, and also opening new possibilities to individual shops. This brigs up new issues. Like, what if the normal accuracy gets so high that the instruments sound too similar to each other? Will it become desirable to build in a certain amount of random variation?

A DRO Fret Slotter

2018
AL#135 p.58               
Mark French                                                                                           

▪ Want a robot lutherie apprentice? It is here today and it is cheap. But it doesn’t look like something from the Jetsons. It looks like this; a digital readout connected to a lead screw. With a friendly whirr, it will move the saw guide right up to the next fret position for you. But get your own dang coffee.

Making Long-Radius Curve Templates

2018
AL#134 p.60               
Mark French   David Zachman                                                                                       

▪ There are times when a luthier may want to draw a good long-radius arch. If jury-rigging a 25-foot compass seems like a hassle, you may have been tempted to just bend a straight stick a little and call it good. Turns out that’s a better solution than you may have thought. This article evaluates several techniques and gives the math that undergirds them.

Meet the Maker: Mark French

2018
AL#133 p.22               
R.M. Mottola   Mark French                                                                                       

▪ Mark French was a kid who took guitar lessons and paid the guy at the music store to change his strings. He went on to be an aerospace engineer, but with all that book learning he still did not know how guitars worked. Now he teaches college courses on guitar making and hangs out with captains of industry at Fender and Taylor.

A Better Approximation to the Rule of 18

2017
AL#132 p.62               
Mark French                                                                                           

▪ We think the old boys found the 1st fret position by dividing the string length by 18. Then they divided that by 18 to get the 2nd fret. Sounds like a job for that nerdy apprentice kid. But 18 is just an approximation of the “right” number; that is, the 12th fret won’t be right in the middle of the string. If you want to do it by hand, here’s some thoughts and numbers about what would be a better approximation, and how much better it would be.

A Simple Modification to Reduce Frequency Errors in Guitars

2016
AL#125 p.64               
Mark French                                                                                           

▪ Professor Mark French and his college students attempt to move the first two frets back a little, and push the nut forward a lot for mathematical accuracy.

Questions: Writing a Book on Guitar Building

2014
AL#119 p.68               
Leo Lospennato   Mark French   John Bogdanovich                                                                                   

▪ Extensive advice on conceiving, structuring, and publishing a book on guitar building.

Making a Truly Flat Sanding Bar

2013
AL#113 p.62               
Mark French                                                                                           

▪ Precisely flat sanding bars are critical to the development of both science and manufacturing; thus the process of ‘lapping’ in necessary, as described by French.

Reducing Build Variation In Arched Plates

2010
AL#101 p.60               
Mark French   Eddie Efendy                                                                                       

▪ Imagine a CNC router carving an archtop guitar soundboard in an industrial situation. Quality control would check to confirm that parts are the same thickness. But really, we would like the tops made from stiffer material to be cut thinner. Efendy has an idea for making this happen automatically without any measurement or analysis needed.

Inharmonicity of Guitar Strings

2009
AL#100 p.48               read this article
Mark French                                                                                           

▪ Guitar strings need to be the “wrong” length in order to sound “right.” The gloriously simple math of Pythagoras doesn’t accomplish this. French uses lasers and spreadsheets, more numbers, and Greek letters to attempt to get closer.

Questions: North American Wood

2008
AL#94 p.66               
Mark French   Ned Steinberger   Alan Carruth                                                                                   

▪ Synthetic fretboard materials such as phenolic-impregnated kraft paper laminate as an alternative to tropical hardwoods.

Taylor Today

2007
AL#90 p.22      ALA1 p.72         
Mark French                                                                                           

▪ Taylor Guitars started out as the sort-of-goofy new kid on the block and has grown into the largest production steel string guitar facility in the country. Maybe you’ll learn something from this factory tour and maybe you won’t, but it’s always fascinating to see how the big guys do things. It’s the state of the art in large production. With 25 photos.

Build Variation in a Group of Acoustic Guitars

2007
AL#90 p.28      ALA1 p.78         
Mark French   Kendall Brubaker                                                                                       

▪ The authors measured frequency response of dozens of similar Taylor guitars using a hammer and a noncontacting laser displacement sensor. The big surprise was that guitars made of various woods didn’t differ very much. Well, some people were surprised. With 4 photos and 7 graphs.

A Different Way of Defining Body Shapes

2006
AL#88 p.52               read this article
Mark French                                                                                           

▪ The author discusses the curve fit, a mathematical method of describing a shape that a computer, and thus a CNC machine, can understand. Curve fits have other benefits, too, but computer illiteracy prevents them from being described here. Includes a plethora of charts and graphs.