Posted on July 8, 2024May 14, 2025 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 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 July 1, 2024May 29, 2025 by Dale Phillips Questions: Online Lutherie Info Questions: Online Lutherie Info by R.M. Mottola Originally published in American Lutherie #68, 2001 See also, Questions: Online Lutherie Chat by Cyndy Burton R.M. Mottola of Newtonville, MA responds to the question in AL#67 regarding where to have your lutherie questions answered online: I’m sure you’ll get lots of responses that give specific URLs, but here is some background and a way to find most places where you can ask your questions. The internet is generally considered to have three basic facilities — e-mail, websites, and Usenet newsgroups. There are discussion groups on the topic of instrument making that use each of these facilities. To find those implemented as websites you can use any internet search engine to search for appropriate terms. Typing “guitar discussion” into a search engine will get you a lot of hits. Finding discussion groups implemented as e-mail mailing lists could be tricky, as there are no comprehensive search facilities for such mailing lists. Fortunately most if not all e-mail-based discussion groups have a website too, so the search specified above will find those as well. Although most folks are not familiar with Usenet, it contains probably the single largest collection of topic-specific discussion groups. Rec.music.makers.builders is the grand daddy of all instrument building discussion groups, and is a Usenet newsgroup. You can access newsgroups using special facilities included in any web browser. Or you can go to one of the Usenet specific search engines such as Deja News (http://dejanews.com) and follow instructions there for posting to and reading selected newsgroups. ◆
Posted on June 13, 2024May 15, 2025 by Dale Phillips Fretboard Slotting with a CNC Router Fretboard Slotting with a CNC Router by John Svizzero and R.M. Mottola Originally published in American Lutherie #98, 2009 Lutherie shops with CNC machines use them for a number of applications, some of which are discussed in the article “Desktop CNC Machines” in AL#77. We (authors Svizzero and Mottola) met at meetings of the New England Luthiers and began comparing notes on our shop-built CNCs. Svizzero’s full-sized machine uses Porter-Cable routers as spindles, and Mottola’s desktop machine uses the Proxxon grinder. We have each been using CNC routers in our own shops for slotting fretboards. By CNC routing standards, fretboard slotting is a slow operation due to the small diameter end mills used (typically .022" to .025"), but in our small shops we have found slotting in this manner to be both cost effective in terms of time and to offer some advantages that other slotting schemes do not. With a suitable CNC machine already in the shop, it is possible to experiment with CNC fretboard slotting with a small investment in tooling and time. Our experiences may help others get over some of the startup problems. 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 June 6, 2024May 14, 2025 by Dale Phillips Another Method for Calculating the Area of a Plate Another Method for Calculating the Area of a Plate by R.M. Mottola Originally published in American Lutherie #70, 2002 and Big Red Book of American Lutherie Volume Six, 2013 There are a number of reasons to calculate the area of the plate of a stringed instrument. The area of a flat plate can be used to determine the volume of the instrument by simply multiplying the area by the depth. This value is useful in the design of electric guitars and basses to determine the weight of the body of the instrument before it is built. This info can aid in the design of an instrument that balances well when hanging from a strap or sitting on the leg. In the design of acoustic instruments, the volume can be used to calculate the nominal Helmholtz resonance of the soundbox, which may be useful in the tuning of the resonance characteristics of the instrument. The technique specified here will work for any arbitrary shape and is both simple and relatively quick. It is the essential algorithm of a CAD script I use, and is based on a computer graphics rasterization technique. Modified and simplified for use with pencil and paper, it yields a good enough approximation of the area of a plate for the purposes outlined above. 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 21, 2023May 29, 2025 by Dale Phillips Calculating Soundbox Volume Calculating Soundbox Volume by Dave Raley Originally published in American Lutherie #70, 2002 and Big Red Book of American Lutherie Volume Six, 2013 Want to design a new guitar shape and maintain an equal volume of enclosed air by adjusting the height of the sides? Here’s how to calculate volumes. Accuracy is a function of how long you want to spend measuring and calculating. Consider two bodies: Figs. 1a and 2a. The body in Fig. 1 is 18" on the X axis and 4" on the Z axis. Suppose that you wish to make the body in Fig. 2 have the same volume as the body in Fig. 1 while maintaining the same X axis. Fig. 3 defines the axes regardless of the way the figures are turned. 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.
