Electric Guitar (How Products are Made)
Developed in the early part of the twentieth century, the electric guitar has become one of the most important instruments in popular music. Today's solid-body electric guitar derives from the acoustic guitar, an instrument first introduced in America as the Spanish-style guitar. Even though body designs of modern electric guitars often differ from their acoustic predecessors, all guitars are constructed with the same simple template. All guitars, acoustic or electric, are built with a bridge, body, and neck. The most significant difference is that acoustic guitars are hollow while electric guitars have a solid body.
For years, the acoustic guitar was limited to a supporting role in large musical ensembles because of its volume. Thus, the major motivation that drove the creation of the electric guitar was instrumentalists' desire for greater volume. Predecessors of the modern electric guitar were amplified acoustic guitars crudely modified by inventors who attached wires, magnets, and other "pickup" attachments. (Pickups are electromagnetic devices that increase volume.) However, as technology started advancing in the 1930s, newer versions became more complex, and the electric guitar became a solo instrument, a development that helped expand musical styles.
The earliest electric guitars were made in the 1920s and 1930s, but these were very primitive prototypes of the modern solid-body electrical guitar. The very first electrified guitar was said to have been invented by Paul H. Tutmarc. Inspired by the inner workings of the telephone, which employed magnetics to create vocal vibrations, Tutmarc experimented on the Hawaiian guitar, building a magnetic pickup out of horseshoe magnets and wire coils that amplified the vibration of the instrument's strings.
Around the same time, George Beauchamp and John Dopyera, two Los Angeles musicians, worked on creating even louder guitars. After experimenting with attaching amplifying horns to instruments, they, too, developed an electromagnetic pickup, this one comprised of two horseshoe magnets. Pleased with the effectiveness of the pickup, Beauchamp had a craftsman make a guitar designed with a wooden neck and body. Nicknamed the "frying pan" because of its shape, this became the first electric guitar. Beauchamp took the prototype to Adolph Rickenbacker. The two men formed a company and began manufacturing the first of the famous Rickenbacker line of electric guitars. Thus, Rickenbacker became the first manufacturer of electric guitars.
The first "Spanish-style" electric guitar was built and sold by Lloyd Loar, another early experimenter. His design was the direct predecessor of the modern electric guitar, and it inspired Orville Gibson, another guitar pioneer, to create the electric guitar model that revolutionized the instrument: the ES-150. Slide guitarist Alvino Rey developed the prototype of the ES-150, which has been called the first modern electric guitar. The final version was built by Gibson employee Walter Fuller. Though the guitar was an immediate success, it had some flaws. The vibrations from its hollow body were picked up and amplified, which created feedback and distortion. This led Les Paul, a guitarist and inventor, to develop the solid body electric guitar in 1940.
Paul's innovation, which was called "the Log" because of its solid body, involved mounting the strings and pickup on a solid block of pine to minimize body vibrations. The "Log" consisted of two basic magnetic pickups mounted on a 4 4 in (10.2 10.2 cm) piece of pine. To make it look more like a conventional guitar, Paul sawed an arch-top guitar in half and attached the pieces to his model. The solid body proved effective in eliminating the problems of the ES-150.
In 1946, Paul took his new guitar to Gibson, who was skeptical about the solid body. Leo Fender, however, understood the conception, and in 1949, he started selling the "Esquire," which became the first successful solid-body guitar. The guitar was later renamed the "Telecaster," one of the most famous guitar brand names. The Telecaster became extremely popular with country, blues, and rock and roll musicians. The Telecaster prompted Gibson to build his own solid-body model, which was named the "Les Paul."
In 1956, Rickenbacker introduced the student model Combo 400 guitar, with its so-called "butterfly-style" body. The guitar's unique construction featured a neck that extended from the patent head to the base of the body (known today as neck-through-body construction) and with the sides of the guitar body bolted or glued into place.
By the 1960s, the electric guitar was an established musical instrument. Innovations in design continued through the decade. In 1961, Gibson introduced "Humbucking" pickups into the Les Paul guitar that were designed to eliminate unwanted hum from the magnetic coils. (Humbucking pickups used two coils wrapped out of phase. This eliminated the common mode hum present in previous designs.) That same year, McCarty introduced the ES-335, a semi-hollow body guitar designed to incorporate the best of both the hollow body and solid body designs. Both Gibson and Fender had introduced futuristic looking designs. The Gibson SG and the Fender Stratocaster became familiar to audiences because they were frequently used by rock guitarists in the 1960s.
Raw materials that go into the construction of the electric guitar include well-seasoned hardwoods such as maple, walnut, ash, alder, and mahogany for the solid body. The denser the wood, the better sustain an instrument will have (sustain refers to how long a note can be held). Wood density can also have an effect on the tone. Some bodies are also constructed with plexiglass. Wood is also used in the construction of the neck, including maple, rosewood, and ebony. Other raw materials include glue to hold the pieces together, chrome for the hardware, and a nitrocellulose lacquer for finishing the body.
The solid-body electrical guitar gets its volume from the magnetic pickup installed within its body. This pickup responds to the vibration of strings, transforming the energy into electrical impulses that are amplified by a loudspeaker system called an amplifier. For the best sound, the pickup needs to be stable and unaffected by vibrations from the body. Early electric guitar pioneers discovered that a pickup connected to a hollow-body acoustic guitar resulted in distortions and feedback. The need for stability is what led to the development of the solid body, the one feature that most characterizes the electric guitar. The solid body increases stability, and early electric guitar makers discovered, through experimentation, that guitar bodies made of high-density hardwood worked best.
In the late 1930s and 1940s, guitarists and inventors like Les Paul and Leo Fender developed the early designs of the solid-body electric guitar. Later, manufacturers moved away from traditional shapes and colors and came up with their own designs, many of which were quite fancy. More advanced models included the Fender Stratocaster and the Gibson Flying V.
The Manufacturing Process
The major components of the electric guitar include the bridge, the body and the neck. Secondary components include the fingerboard, strings, nut and tuning heads. A guitar manufacturing facility is, to a large extent, a woodworking facility, as wood selection and body design are large parts of the electric guitar construction process.
- Wood is selected, inspected, and processed to be made into bodies, necks and fingerboards. Sometimes it must be cured first in a conventional or vacuum kiln to maximize its stability. Curing can take as long as a week, and it relieves stress and wetness. The wood that will be made into a body is loaded onto a scissors lift and transferred to a conveyor where it is planed on both sides. It then moves down to the cut-off saw worker, who cuts the wood to size. From there, the wood is sent to a machine called a KOMO, a computer-controlled router that drills weight relief holes to make the wood lighter. The machine also cuts a channel in the wood where wire will eventually be placed.
- The wood then goes back into the rough mill, where it will have a maple top and mahogany back glued on in a glue mill under 900 lb (408 kg) of pressure. It is then placed on a glue wheel to dry for four hours. Up to this point, the wood is a square block. When dry, it is ready to be shaped. It is sent back to the KOMO, which is programmed to cut the periphery into the desired shape. The KOMO also routs the back electronic pockets.
- The body then goes to the body line for its final shaping. First, a worker sands the body by hand with sandpaper, then it undergoes a process called "rabbeting." Rabbeting involves first making a machine cut that will accommodate the binding that the body needs. The worker maneuvers the body while the machine makes the cut. The body then moves down the line to the binding station. The worker takes the binding material, drenches it in glue by pulling it through a glue box, then wraps it around the rabbet cut made in the body. The worker then ties the body completely with rope to hold the glued binding material in place. Then the body is hung overnight to dry.
- The next morning, the worker removes the rope, and the body moves to the next station, where it will be shaped by sanding into its finished contour. Using a rim sander, a worker sands off the excess glue and ensures that the binding and the wood are flush. The body then goes to the slack belt machine for smoothing. The worker, by hand, places it under a slack belt and pushes the body under the belt with varying pressure until all carved marks are smoothed out.
- As the body of the guitar is built on the body line, the neck of the guitar is built on the neck line, where the neck is shaped and sanded by hand and the fingerboard and head veneer are applied.
- Fingerboards are made of rosewood and ebony and are stabilized in kilns, shaped, and slotted for frets. In shaping, the fingerboard first gets molded on a molder with a 12-in (30.5 cm) radius. From there, it moves into the rough board area, where location pin holes are drilled. Then it goes to the fret saw machine, where the fret slots are cut by a quick saw machine. A router then creates the inlay pockets on the fingerboard, and the inlays are added. The router is a powermatic tool that suctions the fingerboard down on a table and routs all of the pockets. The inlays themselves are placed in by hand at the inlay station. A worker places epoxy into the pockets, puts in the inlays, then places more epoxy on top of them. This eliminates any spaces. The fingerboard is then left to dry.
- When dry, the fingerboard moves on to a surface grinder that cleans the dried epoxy off of the top. Now the frets are ready to be placed. A worker takes the fingerboard and puts glue into the fret slots and then, by hand, places the fret wire. Using a pneumatic snip, the worker first places the wire then cuts off the excess. From there, the fingerboard is put into a hydraulic press that presses the frets completely in place. The worker then hand-sands the frets to make them smooth. The fingerboard is then slotted to accommodate binding, then left to dry. When the frets are dry, the fingerboard is joined to the neck.
- In the meantime, the neck has been built. This begins when the ten-quarter mahogany neck blanks are quarter-sawn for increased strength and straightness. Neck pattern templates are penciled, and then the neck blank is cut into the template shape with a bandsaw. The neck blank is then put on a rotary profile lathe. The lathe gives the neck its basic shape.
- A worker then joins the fingerboard to the neck by tapping in the location pins on the fingerboard, applying the glue, putting the fingerboard and the neck together, placing the connected pieces into a glue press, and then allowing it to dry. The head-stock veneer is also glued onto the neck blank. The neck is then sent down the line to be shaped and finished by machine rolling and hand sanding. Now the neck is ready to be fitted to the body. In attaching the neck to the body, several methods are used by different manufacturers.
- On the body, the location of neck placement is then traced. A cavity is cut where the neck will be placed. The worker places the neck in the neck slot to see if the fingerboard, neck, and body are all flush. Neck fitting is all done by hand, with a worker using a chisel, a clamp, and glue. The neck is then placed in the joint until a seamless fit is made. The fit is glued, clamped, and left to dry for an hour. When dry, the worker sands off the excess glue. The pickup cavities and bridge holes are added by a computer-controlled router.
- The guitar is now ready to for color preparation and finishing. Before applying
- Before the body is sprayed with a finish, the body and neck are sealed to ensure that paint will not be absorbed into the wood. When the guitar dries, the finish is applied by using automated electrostatic methods that improve the consistency of the finish. Afterward, the guitar is sent to the scrapers, who remove any overspray with metal tools.
- After the guitar has dried and has been sanded, it goes into the buffing department. Buffing is a three-step process. First the guitar is buffed on a wheel. A jeweler's rouge compound is used to remove any rough spots in the finish. Two more buffings are then done to achieve a brilliant gloss.
- The guitar now awaits final assemblage, where all of its hardware and electronics are installed. In general, at most guitar manufacturing factories, the final assembly of an electric guitar involve the pickguard placement, vibrato installation, setting the neck, tuner installation, installing strap bottoms, fret dress, nut, bridge and vibrato set up, string tree placement, and pick-up height.
- Next, the hardware and electronics are assembled and placed onto the body and bridge. Hardware placed onto the body include the pickguard, pickguard shield, pickup compression spring, pickup cover, pickup core assembly, lever knob, pickup selector switch, volume knob, tone knob, volume and tone potentiometers, ceramic capacitor, and output plug assembly. Hardware placed on the bridge include base plate, vibrato block, compression springs, bridge bar, set screws, bridge cover, rear cover plate, tension spring, tremelo tension spring holder, and lever assembly.
- Builders install pickups, pots, tuning keys, jackplates and toggle switches. The adjusters notch the tailpiece and nut, string the guitar, check neck pitch and intonation, and adjust the bridge height. The cleaners remove smudges and dirt, install back plates, pickguards, truss rod covers and other hardware and then polish the chrome, nickel or gold hardware.
- The guitar undergoes a final buff and polish and a final inspection.
During each stage of the process, the product is inspected. Even the smallest flaw in design such as a scratch or excess dried glue could send the guitar back down the line, or might even cause inspectors to scrap it. During final assembly, when hardware and wiring is installed, each component is tested separately to verify that it is working properly.
It is generally considered that the great part of the evolution of the electric guitar took place in between the late 1920s and the early 1960s, a period that saw the creation of the major innovations. However, guitar manufactures and inventors are still exploring ways to modify the instrument. These changes would include modification in design, materials, in pickups, or in finishes. Some guitar makers are looking to bodies made of plastic or graphite. Others are exploring designs that include hollow or semi-hollow bodies. For some time now, inventors have been trying to apply piezo to guitar pickup, or amplification. Piezo is a material with piezoelectric properties. If applied correctly to a musical instrument, it senses vibrations or changes in pressure. For a guitar, it could be applied in a contact microphone, or it could be placed on the guitar itself, where it would sense guitar vibration. Ultimately, it could enhance the sound of a guitar.
In the design area, a company has developed a mass 3D solid and surface modeling software that has attracted the attention of the Gibson, Warmoth, Suhr, and Tom Anderson Guitarworks guitar companies. The software would free designers from the limitations of two-dimensional planning and allow them to create complete three-dimensional designs before the manufacturing process began. In this way, they could be more experimental with designs. Potentially, the software would allow designers to create new designs in 3D without having to build prototypes or models. Designs could then be sent to a computerized woodworking station for a limited production run.
Bacon, T., and P. Day. The Ultimate Guitar Book. New York: Alfred A. Knopf, 1992.
Denyer, R., I. Guillory, and A. M. Crawford. The Guitar Handbook. New York: Alfred A. Knopf, 1987.
Wheeler, Tom. The Guitar Book. New York: Harper and Row, 1998.
Rickenbacker Web Page. December 2001. http://www.rickenbacker.com/us/ehistory.htm>.
The Electric Guitar Web Page. December 2001. http://www.si.edu/lemelson/guitars/noframes/00main.htm>.