Posted on March 3, 2024March 6, 2024 by Dale Phillips Mask for Belt Sanding Mask for Belt Sanding by John Calkin Published online by Guild of American Luthiers, March 2024 My 6×48 belt sander is my favorite and most used machines, though getting the most out of it didn’t come easy. It takes a knack to use one accurately, and that took years to develop. Perhaps most importantly, I learned to join plates and sculpt necks, saving myself scads of time over the years. This tip is about sanding parts on nearly completed instruments. It can be dangerous because the plates are already as thin as desired. In this case I needed to take down the end blocks of a dulcimer to the level of the plates. I had already shaped the sides of the blocks using a disk sander and sanding blocks. I used a scrap of poster board to mask the plates as I took down blocks to meet the plates. The end blocks weren’t that much oversize. A hand plane might have done this job as fast as my belt sander, But I never use handtools if a machine will do the job. Whew! I cut it close on this one, but it’s OK. The back of this dulcimer was already thinner than I liked. The block on the bridge end has to be larger to make room for some sort of string fixtures. There are also blocks inside the dulcimer to support the end blocks. The mask doesn’t have to be fancy or cover the entire plate. Sanding the block is done in quick steps with visual checking at every step. No sweat this time. All of the hand pressure on the sanding belt is applied to the block. I usually keep 80 grit belts on my sander. Sixty-grit would last longer and cut faster but the scratches require more work to remove. The abrasive barely touched the mahogany on this end. Most belt sanders of this size come with a 9" disk sander attached, but right from the factory mine wobbled badly. It was also frequently in the way, so I dismantled it. I considered returning the machine to Woodworker’s Supply, but repacking it would have been a lot of work. They still sell this machine. If they haven’t improved I wouldn’t buy it again. Standing the belt 90 degrees to the supplied work table turned out not to be a big deal, so I didn’t miss the disk sander very much. ◆
Posted on March 3, 2024March 6, 2024 by Dale Phillips Humbucking Pickup Wiring Humbucking Pickup Wiring by Daniel P. Coyle Originally published as Guild of American Luthiers Data Sheet #203, 1982 The use of dual-coil or “Humbucking” pickups enables a wide range of samples of string sounds, along with a heightened complexity of switching problems. A flexible switching installation for either 6-string electric guitars or electric basses has the ability to arrange the coils of the two separate pickups in the following configurations: a) Pickups in either series or parallel configuration. b) Coils within the pickups in either series or parallel configuration. c) Coils within the pickups arranged as “single-coil” or “Humbucking”. d) Ability to select either pickup individually or both pickups at once. e) Phase reversal between pickups. f) Tone control defeat. g) The regular volume control and high-cut tone control. 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 March 1, 2024March 7, 2024 by Dale Phillips Trimming Violin Bridges Trimming Violin Bridges by George Manno Originally published in American Lutherie #6, 1986 Few will argue the statement that there are no two violins the same, even if the arching, graduation, position of the bass bar and soundpost, and even the preparation of the wood may seem to be exactly the same. All violins do share some of the same properties, but each instrument has a single property of its own that distinguishes it from another. You’d be surprised what 0.1MM, either in thickness or thinness, can do to the sound of an instrument. An adjustment that minute can change the tone tremendously. Does the same hold true for a violin bridge? Yes and no. The following is my personal expansion upon the information given in Data Sheet #224 by Alan Carruth. As Mr. Carruth states, violin bridge tuning is a trial and error situation which is challenging when searching for an instrument’s highest potential. 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, 2023March 5, 2024 by Dale Phillips Battery-Powered Instrument Amplifiers Battery-Powered Instrument Amplifiers by Joseph Ennis Originally published in American Lutherie #69, 2002 and Big Red Book of American Lutherie Volume Six, 2013 After reading Francis Kosheleff’s description of building speaker enclosures which resemble instrument bodies, I thought I would offer my experience of what has worked for me. I have added battery-powered amplifiers and speakers inside instrument bodies to either augment the sound of a weak instrument like a harp or mandolin, or just to act as stage monitors. The thing left unspoken in Mr. Kosheleff’s article is that not just any speaker will work well. The speaker should be chosen to match the instrument body resonance. The first air resonance of a hollow body instrument is essentially the same as the Helmholtz resonance of a tuned speaker cabinet. The same math applies. The formula is given below. 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 17, 2024 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.
