Machine head

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Open worm type machine head on a ukulele Stemmechanisme ukelele closeup-1.jpg
Open worm type machine head on a ukulele

A machine head (also referred to as a tuning machine, tuner, or gear head) is a geared apparatus for tuning stringed musical instruments by adjusting string tension. Machine heads are used on mandolins, guitars, double basses, and others, and are usually located on the instrument's headstock. Other names for guitar tuners include pegs, gears, machines, cranks, knobs, tensioners, and tighteners.

Contents

Non-geared tuning devices as used on violins, violas, cellos, lutes, older Flamenco guitars, and ukuleles are known as friction pegs, which hold the string to tension by way of friction caused by their tapered shape and by the string pull created by the tight string.

Construction and action

Machine heads on a double bass Contrebasse clefs.jpg
Machine heads on a double bass

Traditionally, a single machine head consists of a cylinder or capstan, mounted at the center of a pinion gear, a knob or "button" and a worm gear that links them. The capstan has a hole through the far end from the gear, and the string is made to go through that hole, and is wrapped around the capstan. To complete the string installation, the string is tightened by turning the capstan using the tuning knob. The worm gear ensures that the capstan cannot turn without a movement on the knob; it also allows precise tuning.

Banjos usually employ a different mechanism using planetary gears - in this case, the knob and the capstan both rotate on the same axis. A few guitars (e.g. the original Gibson Firebird, early Gibson basses and Mario Maccaferri's plastic instruments) have used this design.

The guitarist adjusts the tension of the various strings using the knobs so that they are correctly tuned: a higher tension yields a sharper pitch, a lower tension a flatter pitch. Typical tensions for steel-string acoustic guitars with "light" tension strings are 10.5  kgf (23.3  lbf, 103 N) to 13.8 kgf (30.2 lbf, 135 N).

Varieties

Several kinds of machine head apparatus exist:

The machine heads on a classical guitar. Note the exposed gears and the decorations. Classical guitar head gears DSC06945.jpg
The machine heads on a classical guitar. Note the exposed gears and the decorations.
Martin EB18 bass guitar headstock, showing Martin open-type machine heads. MartinEB18Headstock.jpg
Martin EB18 bass guitar headstock, showing Martin open-type machine heads.
The reverse of the machine heads on a "folk" steel-string acoustic guitar. Note the enclosed gears. Folk guitar head DSC06938 reverse.jpg
The reverse of the machine heads on a "folk" steel-string acoustic guitar. Note the enclosed gears.

On some guitars, such as those with Floyd Rose bridge, string tuning may be also conducted using microtuning tuners incorporated into the guitar bridge.

Likewise, 'headless' guitars and basses, notably those designed by Steinberger and their licensed imitations, such as the Hohner Jack Bass, and unlicensed imitations such as the Washburn Bantam, have the machine heads at the body end. Steinbergers and Hohners require specialist double-ball end strings, whereas the Washburn Bantam can take regular strings.

Presently, most worm-gear tuners provide a gear ratio of 14:1. In older designs, 12:1 was common, and lower ratios as well. Lower ratios allow a replacement string to be brought more quickly up to pitch, though with less precision for fine-tuning. Lower ratios are also more forgiving of imperfect machining, and of factors that might compromise the gear surfaces (corrosion, grit, poor lubrication).

As increased precision of milling became more cost-effective, higher ratios appeared on the market, with 14:1 being the modern standard, trading accuracy against slower initial string winding. More recently, versions with an 18:1 gear ratio are available (particularly from Grover), and the Gotoh 510 offers 21:1.

Locking tuners

The term "locking tuners" has two meanings. Presently, it refers to some sort of mechanism in the string peg (usually a cam or screw) that locks the string in place, preventing slippage. With the popular increase of extreme vibrato-arm usage in the 1980s, several manufacturers introduced a modified design, commonly called locking machine heads, where the individual tuner has an additional mechanism to lock the string in place and stabilize tuning, primarily intended for musicians who make regular use of the vibrato. Some designs increase string breakage at the point they grip the string.

The term "locking" is much older, possibly originating with Grover, and refers to an "anti-backlash" design of the gears, which greatly reduced the slippage of the basic worm-and-gear system. The gear's teeth are shaped to lock into those of the worm, with the string tension insufficient to overcome the friction between the gears. Such a design is called self-locking. Grover Rotomatics and similar designs from other manufacturers are rightly called "locking tuners."

Resistance to usage

Musicians playing certain instruments, most notably the violin family, (excepting the double bass) remain resistant to the use of machine heads, insisting on the continued use of friction pegs. Such factors as appearance, weight, tradition, and simplicity are cited as justification, despite issues with friction pegs slipping out of tune, coming loose, or jamming. In the early 2000s, tuning pegs were introduced with planetary gearing inside a friction-peg shaped casing that can be fitted to an instrument without physical alterations. While reasonably well-accepted, planetary pegs can make string changes more time-consuming.

Innovators

See also

Related Research Articles

Tuner may refer to someone or something which adjusts or configures a mechanical, electronic, or musical device.

Floyd Rose

The Floyd Rose Locking Tremolo, or simply Floyd Rose, is a type of locking vibrato arm for a guitar. Floyd D. Rose invented the locking vibrato in 1976, the first of its kind, and it is now manufactured by a company of the same name. The Floyd Rose gained popularity in the 1980s through guitarists like Eddie Van Halen, Neal Schon, Brad Gillis, Joe Satriani, Steve Vai, and Alex Lifeson, who used its ability to stay in tune even with extreme changes in pitch. Its tuning stability comes through the double-locking design that has been widely regarded as revolutionary; the design has been listed on Guitar World's "10 Most Earth Shaking Guitar Innovations" and Guitar Player's "101 Greatest Moments in Guitar History 1979–1983."

Inharmonicity

In music, inharmonicity is the degree to which the frequencies of overtones depart from whole multiples of the fundamental frequency.

Appalachian dulcimer fretted string instrument

The Appalachian dulcimer is a fretted string instrument of the zither family, typically with three or four strings, originally played in the Appalachian region of the United States. The body extends the length of the fingerboard, and its fretting is generally diatonic.

A vibrato system on a guitar is a mechanical device used to temporarily change the pitch of the strings. Instruments without a vibrato have other bridge and tailpiece systems. They add vibrato to the sound by changing the tension of the strings, typically at the bridge or tailpiece of an electric guitar using a controlling lever, which is alternately referred to as a whammy bar, vibrato bar, or incorrectly as a tremolo arm. The lever enables the player to quickly and temporarily vary the tension and sometimes length of the strings, changing the pitch to create a vibrato, portamento, or pitch bend effect.

Steinberger

Steinberger is a series of distinctive electric guitars and bass guitars, designed and originally manufactured by Ned Steinberger. The name "Steinberger" can be used to refer to either the instruments themselves or the company that originally produced them. Although the name has been applied to a variety of instruments, it is primarily associated with a minimalist "headless" design of electric basses and guitars.

Tailpiece

A tailpiece is a component on many stringed musical instruments that anchors one end of the strings, usually opposite the end with the tuning mechanism.

Floyd Rose SpeedLoader

Floyd Rose SpeedLoader is a floating guitar bridge based on the Floyd Rose Original. In development since 1991, it was introduced to the public in 2003. This tremolo was developed in San Diego CA at AJ manufacturing by tool makers Jerry Morhman, Richard J Price, Steve Lamms, and Kerry L Stottlemyer under the direct guidance of Floyd Rose himself. With Richard J Price doing the majority of the design work and machining of the prototypes. Over 3000 hours and $150,000 were spent in developing this new ground breaking tremolo system and the first working unit on a guitar body. It inherited the locking floating bridge principle from the original version, but improved usability and diminished most of disadvantages that the Floyd Rose Original was criticized for, while adding the inconvenience of needing special-purpose strings. The Floyd Rose SpeedLoader is available in Tremolo, Fixed Bridge, and Convergent Tuning forms. However, the issues with strings became more apparent, as the specially made strings for the Speedloader were discontinued due to quality control issues. With no strings currently being manufactured, there is no way to properly string and set up any guitar with the Floyd Rose Speedloader. Customers have voiced their discontent with Floyd Rose for a lack of development of any parts that could remedy the situation.

Worm drive Gear arrangement

A worm drive is a gear arrangement in which a worm meshes with a worm wheel. The two elements are also called the worm screw and worm gear. The terminology is often confused by imprecise use of the term worm gear to refer to the worm, the worm wheel, or the worm drive as a unit.

A nut, on a stringed musical instrument, is a small piece of hard material that supports the strings at the end closest to the headstock or scroll. The nut marks one end of the vibrating length of each open string, sets the spacing of the strings across the neck, and usually holds the strings at the proper height from the fingerboard. Along with the bridge, the nut defines the scale lengths of the open strings.

Tuning mechanisms for stringed instruments Different types of stringed instrument parts and their methods for tuning stringed instruments

A variety of methods are used to tune different stringed instruments. Most change the pitch produced when the string is played by adjusting the tension of the strings.

Violin construction and mechanics

A violin consists of a body or corpus, a neck, a finger board, a bridge, a soundpost, four strings, and various fittings. The fittings are the tuning pegs, tailpiece and tailgut, endpin, possibly one or more fine tuners on the tailpiece, and in the modern style of playing, usually a chinrest, either attached with the cup directly over the tailpiece or to the left of it. There are many variations of chinrests such as clamped to the body in the center, on either side of the tailpiece as with a Guaneri style chinrest or to the left of the tailpiece.

Electronic tuner

In music, an electronic tuner is a device that detects and displays the pitch of musical notes played on a musical instrument. "Pitch" is the perceived fundamental frequency of a musical note, which is typically measured in Hertz. Simple tuners indicate—typically with an analog needle-dial, LEDs, or an LCD screen—whether a pitch is lower, higher, or equal to the desired pitch. Since the early 2010s, software applications can turn a smartphone, tablet, or personal computer into a tuner. More complex and expensive tuners indicate pitch more precisely. Tuners vary in size from units that fit in a pocket to 19" rack-mount units. Instrument technicians and piano tuners typically use more expensive, accurate tuners.

Tuning wrench

A tuning wrench is a specialized socket wrench used to tune string instruments, such as the piano, harp, and hammer dulcimer, that have strings wrapped around tuning pins. Other string instruments do not require a tuning wrench because their tuning pins or pegs come with handles, or geared tuning machines.

Rickenbacker 360/12

The Rickenbacker 360/12 is a semi-hollow body with set neck construction electric guitar made by the Rickenbacker company; it was among the first electric twelve-string guitars. This instrument is the 12 string variant of the Rickenbacker 360. Rickenbacker uses an innovative headstock design that incorporates both a slotted-style peghead and a solid peghead, thereby eliminating the need for the larger headstock normally associated with a twelve-string guitar.

Bridge (instrument) Part of a stringed instrument

A bridge is a device that supports the strings on a stringed musical instrument and transmits the vibration of those strings to another structural component of the instrument—typically a soundboard, such as the top of a guitar or violin—which transfers the sound to the surrounding air. Depending on the instrument, the bridge may be made of carved wood, metal or other materials. The bridge supports the strings and holds them over the body of the instrument under tension.

Guitarrón chileno

The Guitarrón Chileno is a guitar-shaped plucked string instrument from Chile, with 25 or 24 (rarely) strings. Its primary contemporary use is as the instrumental accompaniment for the traditional Chilean genre of singing poetry known as Canto a lo Poeta, though a few virtuosi have also begun to develop the instrument's solo possibilities.

EverTune is an American company that produces the EverTune bridge, designed to keep guitar strings in tune.

Viola da terra

Viola da terra is a stringed musical instrument from the islands of the Azores, closely associated with the saudade genre of Portuguese music. Its 12 or 15 metal strings are arranged in either five or six courses.

The Kluson Manufacturing Company, founded in 1925, was a prominent manufacturer of musical instrument tuning machines.

References