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Machining beautiful music

June 30, 2005
Without today's CNC technology, a well-known company couldn't manufacture its guitars.

A Fadal 4020 VMC machines special NT necks at Taylor Guitars.

Without such CNC equipment as its Fadal 4020 VMCs, Taylor Guitars couldn't produce the pockets for its NT necks.

Equipped with a Tecnara right-angle head, this Fadal VMC sands radii on necks at Taylor Guitars.

Taylor Guitars uses lasers to precisely cut its guitar bodies to fit into aluminum assembly molds.

By incorporating ABB robots, Taylor Guitars reduces its buffing time per guitar from 1 /2 hr to 7 min.

Bob Taylor stuck his neck out, so to speak, when he presented to the music world his first attempt at guitar making. He mistakenly carved his guitar's neck too thin, and because he lacked dovetailing skills, he simply bolted the neck to the body. The lutheries of the day were flabbergasted, his first customers were blown away.

Then Taylor went one better. After 15 yr of handmaking his guitars, he incorporated CNC equipment to do the job, and his company grew from a two-man shop to a production-level manufacturer currently pumping out 248 high-end acoustic guitars daily from its factory in El Cajon, Calif.

CNC equipment repeatably duplicates the quality and "feel" of Taylor's original handmade guitars, and more importantly, it lets the company incorporate innovations that are otherwise impossible to accomplish by hand. One such innovation is the New Technology (NT) neck.

On traditional acoustic guitars, necks end at guitar bodies, and fretboards continue over their tops. Since the tops are the only support, fretboards (from the 14th up) move with the body tops when they expand or contract due to excess humidity or dryness. This movement, in turn, creates humps in fretboards where necks join to bodies and causes uneven playing surfaces that negatively affect intonation.

The NT design, on the other hand, uses a wooden neck extension that supports the upper end of the fretboard. This extension, or "paddle" slips into a pocket machined in the guitar's body.

Taylor machines its NT necks and mating pockets in guitar bodies using vertical machining centers from Fadal Machining Centers LLC of Chatsworth, Calif. The shop has 33 Fadal VMCs. Five are in its tooling and prototype areas, while the remainder, mostly model 4020s, produce guitars on the shop floor.

According to Randy Cordes, machine maintenance supervisor at Taylor, the shop uses its Fadals as "tools," not for running only certain types of parts as in typical mass-production environments. Operators stationed at VMCs build necks by adding parts, doing some machining, adding more parts, doing more machining, and so on until necks are completed.

For example, after a VMC profiles and cuts wooden neck blanks in two, operators transfer the pieces to another VMC that cuts neck finger-joints. The two pieces are then glued together, forming the top neck angle.

After some prep work on a specially modified dual-head rotary shaper, the neck assemblies go to a VMC that puts in tuner holes and cuts truss rods. While this is happening, operators remove finished necks, set truss rods, glue on truss-rod fillers, and load neck assemblies into another VMC that cuts the tops.

With veneer applied to their peg heads, necks move to a two-VMC cell using special radius drum sanding tools that apply 9-in. radii. The machines sport MST right-angle heads from Tecnara Tooling Systems Inc. of Santa Fe Springs, Calif., which accommodate industrial-standard collets and deliver 0.0002-in. T.I.R. They cut from 0° to 360° and let Taylor accurately tilt them for its neck radii.

Operators then profile and fret the necks, chamfer frets, cut nut slots, and do other operations on another VMC. Finally, they glue heel blocks onto the necks, which then go to another VMC where their backs are profiled.

Taylor's NT neck design requires consistently accurate guitar bodies that fit into fixtures on the VMCs for machining neck pockets. To do this, the company CNC laser cuts the bodies, and instead of wooden molds, it uses aluminum ones for assembling bodies to within a few thousandths of an inch. The Fadal VMC machining the body pockets runs eight different cutters and produces pockets at ±0.001-in. tolerances.

Two special laser-cut shims ensure perfect neck angles at assembly. One shim goes under the finger board, and the other under the neck's heel block. These shims allow for 45-sec neck-angle adjustments to compensate for factors, such as heat and humidity, that can change the angle.

Prior to incorporating CNC equipment like the Fadals and laser cutters, Taylor had no drawings/blueprints of its guitars, per se, which was a big deal. It needed drawings to reproduce guitars as good as the originals and to generate cutpaths for the CNC machines. The company now generates drawings and cutpaths using SolidWorks and MasterCAM software packages.

Taking its manufacturing technology even further, the company is initiating automation. For example, ABB robots are buffing guitars, and as a result, buffing time per guitar dropped from 1 /2 hr to 7 min.

VMC 4020 Specs

Fadal's VMC 4020 sports a 4820-in. table that supports loads up to 3,641 lb. Cutting feedrates for X, Y, Z run 600 ipm, while rapid rates reach speeds up to 900 ipm in X, Y and 700 ipm in Z. Axis positioning is ±0.0002 in., with repeatable capability of ±0.0001 in.

The machine's electromechanical 40-taper spindle turns from 10 to 10,000 rpm (15,000 rpm optional), and an automatic toolchanger keeps it constantly in the cut by supplying up to 21 tools (24/30 tools optional). Toolchangers accommodate tool diameters as big as 3 in., and, without adjacent tools, ones up to 6 in. in diameter. It houses maximum tool lengths of 15 in. and those weighing up to 15 lb.

From Two Men To Production-Level Manufacturing

Bob Taylor and Kurt Listug cofounded Taylor Guitars. Taylor, who earned several awards in industrial arts competitions at state fairs, hand-built his first three guitars in wood shop classes during his high-school years. After graduating, he got a job making guitars at the American Dream Musical Instrument manufacturing shop in the Lemon Grove area of San Diego, Calif. While there, he met Listug. Listug had dropped out of college to work at American Dream.

One year after meeting, the two bought American Dream. Listug was 21, and Taylor was 19. The company struggled for several years, almost going under a few times. But thanks to some small successes, like Taylor's guitar neck design, an increasing number of famous musicians bought Taylor guitars, and the company grew a little each year.

It now employs 358 in a 140,000-ft 2 complex, which encompasses two factories/office buildings, a case factory, a Baby Taylor guitar plant, and other leased space. Last year, the company manufactured 58,103 guitars.

While Taylor currently has no paid endorsers, some of the biggest names in contemporary music play its guitars. These include Dave Matthews, Clint Black, Jewel, U2, Shania Twain, and Alan Jackson, to name a few.