Tuning mechanism
The tuning mechanics (short: mechanics ) are used in many plucked instruments to tune the individual strings . It is located on the head plate or on the pegbox .
In contrast to the simple vortex , the mechanics (English machine head ) have a translation . This achieves sufficient tuning precision so that additional fine tuners , such as those used in string instruments of the violin family, can be dispensed with.
Requirements and development
The mechanism should at the same time enable easy and stable tuning, so it should combine ease of movement and stability through self-locking . The better this succeeds, the higher the quality of the mechanics. The type of surface treatment, in addition to the manufacturing precision and the torsional stiffness of the base plate, is one of the determining factors for the quality.
The development of the tuning mechanism is often attributed to Charles Louis Bachmann (1778). However, Michael Praetorius already describes a corresponding development from Prague in Syntagma musicum (1619). In England, a W. Gibson manufactured an instrument with a tuning mechanism in 1765. Around 1770 there were the first cistern with a hook mechanism (the string is hooked into a hook that can be moved in the longitudinal direction of the neck through a screw thread - this type of mechanism is still in use today on the Waldzither and the Portuguese guitar ) and was made in 1806 the Berlin lute and guitar maker JG Thielemann first guitars with lateral peg screws. The Viennese guitar maker Johann Georg Stauffer invented the mechanism variant named after him in 1825. Stauffer's student Christian Friedrich Martin ( Martin Guitars ) emigrated to America in 1833 and introduced the new mechanics there.
Components and materials
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A mechanism consists of several parts:
- Base plate (single or multiple) for attachment to the instrument
- Worm gear with worm and worm wheel, rarely also planetary gear for translation
- "Wing" (also "handle" or "button") for operation
- Axis ("adjusting axis", "leg wave") to accommodate the string end
The moving parts of the mechanics are usually cast or milled from metal. The metal surfaces are usually hardened by electroplating . Different metals, for example brass, nickel, chromium or gold, are used for this. Gold plating is considered the highest quality form .
The gearboxes are either open or encapsulated in a closed metal box. In the case of the closed version, a sufficient supply of lubricant is usually added for the service life, so that the gear unit is maintenance-free. In the case of open versions, the gear unit can be cleaned and lubricated from the outside.
The adjusting axes are made either from metal, from metal with a plastic sleeve or completely from plastic or Galalith . The axes are supported either in plain bearings or, in the case of very high-quality designs, in ball bearings .
Different materials are used for the wings : There are versions made of metal, various plastics such as PVC or acrylic , mother-of-pearl or wood. Since the wings have hardly any influence on the mechanical quality, the choice of material and processing is particularly relevant for aesthetics and handling. Depending on the position of the adjusting axis to the wing axis and the adjusting axis to the head plate or to the pegboard or swivel, the wings are either behind or on the side.
Designs and areas of application
The designs are very diverse, both in terms of construction forms and dimensions, so that practically all component combinations occur.
Typical designs and areas of application for plucked instruments can, however, be characterized.
- Concert guitar with gut or plastic strings: Today, the concert guitar usually has an openwork head plate, on which a base plate with three open mechanisms with worm gear and rear wings are mounted on the right and left. The axis distance is 35 mm. The base plate often has engravings or a lyre-shaped decoration on the head end. The positioning axes are made of metal (diameter 6 mm) and have wings made of plastic , acrylic , Galalith or wood (diameter 10 mm). Typical gear ratios: 1:15 or 1:16.
- Guitar with steel strings ( electric guitar or western guitar ): These guitars usually have a solid headstock, on which three base plates are attached to the left and right, each with a closed mechanism with worm gear and lateral wings made of metal or plastic. Other arrangements such as six machine heads on the left (prototypical in the Fender Telecaster model ) also occur on electric guitars ; Adjustment axis made of metal (diameter 6 mm), the axis distance is not specified due to the individual assembly, typical translation: 1:12.
- Electric bass : The arrangement and design is the same as for the electric guitar, but mostly limited to four strings. The mechanics are designed to be somewhat more stable because of the stronger strings, the adjusting axis is made of metal with a diameter of 8 mm and a gear ratio of 1:12.
- Banjo : The banjo usually has a massive headstock on which, depending on the number of strings, four to six individually attached mechanisms with planetary gears are mounted. The metal wings are behind. The adjusting axis is made of metal with a typical diameter of 6 mm and a gear ratio of 1: 4.
- Mandolin : Because of the curved shape of the head plate, base plates with four lateral wings of stepped length are often used in the mandolin. The adjusting axis is made of metal with a typical diameter of 6 mm and a gear ratio of 1:16.
- Guitar lute : the guitar lute has a narrow pegbox in which six axes are attached one behind the other. The mechanics of these axes are arranged alternately left and right.
In the case of string instruments, the double bass is regularly equipped with tuning mechanisms analogous to those of the plucked instruments. They are arranged either individually or with two mechanisms on a base plate (Tyrolean mechanism) . Double bass machine heads are often made entirely of brass with a polished surface. Violins are rarely built with a tuning mechanism; a combination of pegs and fine tuners is common.
Other string instruments also have mechanisms with very different functions. The mechanism of the pedal harp is used to change the key of the entire instrument. In the case of the piano and other keyboard instruments, the transfer from the keyboard to the strings is also referred to as " mechanics ".
Manufacturer
Well-known manufacturers of tuning machines for plucked instruments are
- in Germany: Rubner ( Markneukirchen ), Schaller ( Postbauer-Heng ), Scheller ( Flintbek ), Sommer ( Bubenreuth )
- outside Germany: Gotoh ( Japan ), Rodgers ( England ), Alessi ( Italy ), Grover ( USA )
