Posted on July 8, 2024July 8, 2024 by Dale Phillips Parametric Solid Modeling Software for Stringed Instrument Design Parametric Solid Modeling Software for Stringed Instrument Design by R.M. Mottola Originally published in American Lutherie #87, 2006 Most folks are awed when first witnessing a Computer Numerical Control (CNC) machine shaping an instrument part. Since such a demonstration makes the advantages of using this technology immediately obvious, a number of people look into acquiring these tools for their own use. A substantial portion quickly loses interest when finding out the depth of complexity of the tools needed to design and build in this manner. Computer Aided Design (CAD) software must be mastered in order to draw the parts. Computer Aided Manufacturing (CAM) software must be mastered in order to specify how the drawings will be utilized in the machining process and to control the CNC machine. And the details of the CNC machine itself must be comprehended before real work can be performed. All of this conspires to lead all but the highly technical and/or highly motivated to the conclusion that these technologies need to be made a lot simpler and more accessible before they can be widely exploited in the industry. Adaptation and use of these technologies can be considered analogous to that of the automobile. When first introduced, the car was something only accessible to those who could understand all of the details of the machine (and repair all the parts, too), but eventually it evolved into a more commodity-like device that is usable with little or no knowledge of its inner workings. This article is an introduction to Parametric Solid Modeling (PSM), an existing second-generation CAD technology that offers potential to bring the benefits of CAD/CAM/CNC to a wider user base. A comprehensive library of parametric models of instrument parts and subassemblies could go a long way toward making these technologies generally accessible. The availability of such a library could render a number of aspects of instrument design to sequences of preparing simple drawings and filling in values in forms. No such library currently exists, but it is possible and likely that one could be developed. Folks working with PSM software in this industry undoubtedly have developed such models for their own use. I have some of my own and will use one as an example of how this technology works. 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 July 7, 2024July 9, 2024 by Dale Phillips Questions: Martin Finish Questions: Martin finish by Walter Carter Originally published in American Lutherie #104, 2010 Kerry Char from Portland, Oregon asks: Exactly what kind of finish were Gibson and Martin using before they switched to nitrocellulose lacquer? How was it applied, and when was the switch. I’m thinking that it was oil varnish similar to violin varnish, because it is resistant to acetone. But if that’s the case, how did Gibson do some of their sunbursts? I know that the earlier ones were rubbed, but later ones from the ’20s and ’30s look sprayed. Walter Carter from Nashville, Tennessee replies: Neither Gibson nor Martin made an across-the-line change from varnish to lacquer. Richard Johnston and Dick Boak note in their recent book, Martin Guitars: A Technical Reference, that Martin finishes were French polish (shellac) until 1918, when they began experimenting with different combinations of varnish and lacquer. Martin first used nitrocellulose lacquer in 1926, and by 1929 it was the standard finish on most Martin guitars. For Gibsons, Stephen Gilchrist offers this information: 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 July 7, 2024July 9, 2024 by Dale Phillips Questions: Martin Style 5-18 Questions: Martin Style 5-18 by R.J. Klimpert Originally published in American Lutherie #103, 2010 Larry Crozier from the Internet asks: A customer wants a Martin-style 5-18 guitar built. I was wondering if GAL Plan #8 for the Martin 1-18 is the same or close enough. If not, could you recommend somewhere to get a 5-18 plan? R.J. Klimpert of Barrington, Rhode Island responds: The chief reason that the 1-18 pattern won’t work to build a 5-18 is that the Martin 5-18 is a “terz” guitar, meaning that the neck and scale length are considerably shorter than that of a regular Martin, allowing for the higher-than-standard tuning that terz guitars are known for. The 1-18’s body, while narrow and seemingly similar in size to a 5-18, is too long to allow for a terz short-scale neck. The 5-18 is actually closer to a Martin Style 51 baritone uke in body size and scale. In fact, Martin reportedly reused an old terz guitar pattern when they started producing the 10-string tiple in the late ’teens. As for finding a pattern that would work for building a 5-18, it might be possible to reduce the dimensions of a 000-18 — all except the width of the neck — to approximate the correct size and shape. Or conversely, scale UP the dimensions of a Martin tiple (GAL Plan #37), since the 5-18 terz guitar lies somewhere between the two. ◆
Posted on July 7, 2024July 9, 2024 by Dale Phillips Questions: J-45 Body Questions: J-45 Body by Joe Veillette Originally published in American Lutherie #102, 2010 David Brooks from Tucson, Arizona asks: I want to build a 12-string guitar based on a J-45 body or similar. What changes to the 6-string version of the J-45 do I need to make to handle the additional tension? Joe Veillette from Woodstock, New York responds: In my experience there are two ways to go. If your idea of a 12-string is what most people are used to (25"–25 5/8" scale), I feel that all you have to do is add about 10% to the cross-sectional dimensions of what you’d use for normal 6-string top bracing. The top thickness as well as the back and sides can remain unchanged. This “normal” 12-string should be tuned down a step to D (many old Guilds came that way), or strung with extra-light strings due to the high tension of the octave strings which otherwise tend to be harder to play, more finicky in terms of intonation, and can often deform the top. Of course this isn’t always the case, but it’s close. In my opinion, both detuning and the use of really light strings are unfortunate compromises. But some people prefer the lower tuning and there’s nothing wrong with it if that’s what you like. 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 July 7, 2024July 9, 2024 by Dale Phillips Questions: Unified Repair Pricing Questions: Unified Repair Pricing Originally published in American Lutherie #25, 1991 John Kitakis from Hendersonville, NC writes: I’ve enjoyed toying with the idea of unified repair pricing throughout North America. To me, it seems unprofessional to have a wide variety of charges for the same repair. I suppose everyone has different needs and wants, and overheads vary, so this “discrepancy” may never be resolved. The repairman down the road (who says he doesn’t need much) will continue to charge $100 for a fret job, and $20 to reglue the bridge. I continue to have plenty of business, so I’ll continue to charge more. Below is a list of a few prices. My complete list is available upon request. 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.
