The reverse of the machine heads on a 'folk' steel-string acoustic guitar. Exposed gears are much more common in premium bass guitars than in six-string non-bass instruments. Bass tuners generally feature larger knobs than guitar tuners as well often these are distinctively shaped, and known as 'elephant ears.' Gear ratios of 20:1 are used often. on bass guitars, where string tension is extremely high, larger, heavier-duty machine heads than those used on guitars are used.one diagonal row of four pins and one diagonal row of two pins: found on Music Man guitars.a single diagonal row of 6 pins: found on Fender Telecaster and Stratocaster guitars.rectangular head, 2 rows of 3 pins (or 6 pins for 12-string guitars): found on most 'Folk' and 'Jazz' guitars and on Gibson Les Paul guitars.Several machine head placements are possible, depending on the shape of the headstock: Vintage and vintage-reproduction guitars frequently have individual open-gear tuners, enclosed tuners not having become common until after WWII. on modern steel-string guitars, including 'folk' acoustic and electric guitars, the worm gears are generally placed in individual sealed enclosures with permanent lubrication, although budget models may have exposed gears fixed on plates housing a row of gears.on classical guitars (with nylon strings), the worm gears are generally exposed the strings are wound on the pins inside grooves in the head.Several kinds of machine head apparatus exist: 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). 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.

the original Gibson Firebird, early Gibson basses and Mario Maccaferri's plastic instruments) have used this design. The worm gear ensures that the capstan cannot turn without a movement on the knob it also allows precise tuning.īanjos usually employ a different mechanism using planetary gears - in this case, the knob and the capstan both rotate on the same axis. To complete the string installation, the string is tightened by turning the capstan using the tuning knob. 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. 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.

Airline guitar tuning pegs