Post by Tony Ravenscroft on Apr 27, 2020 11:54:11 GMT -6
Seeing as I wrote (or substantially rewrote) almost all the following on Wikipedia, it might look familiar. 
ORIGINS OF THE TUNING MACHINE
The geared stringed-instrument tuning mechanism -- guitar tuners, machine heads, tuning buttons -- first appeared in the late 1700s, when cittern maker John Preston is often credited with a linear-pull tuning machine.
The next major evolutionary step was when Austrian luthier Johann Georg Stauffer (1778-1853) created the worm-and-gear tuner. The "Stauffer-style" design was brought to the United States by Christian Frederick Martin, founder of Martin Guitars (1833). Over the next century, the worm-and-gear design all but pushed out the use of friction pegs in guitars, banjos, and mandolins, but the fundamental design was virtually the same from one manufacturer to the next.
John Kluson established a Chicago machine shop in 1925, specifically for making tuning machines, with the "Kluson-style" design having each mechanism enclosed in a stamped-sheetmetal shell
Albert Deane Grover (1865 — 1927), born the son of a Boston piano maker, was a banjoist, composer, teacher, and prolific inventor of musical parts and accessories for stringed instruments. He was a founding member of the Boston Ideal Banjo, Mandolin and Guitar Club. Grover held over 50 patents for musical instrument parts, and founded the musical accessories company A. D. Grover & Son, which in 1952 became Grover Musical Products, Inc., of Cleveland, Ohio. The company he founded continued to refine the machine-head concept through the 20th century, as with their open-frame Sta-Tite tuners, still widely copied as "Waverly" tuners. But Grover's most lasting accomplishment was a mid-century design with the mechanism sealed in a cast-metal shell.
THE ROTOMATIC
The Grover Rotomatics were a commercial game-changer, and became original equipment on better-quality guitar models of a couple dozen brands, from the 1960s through the 1990s. The "shell" both protects the mechanism from debris and corrosion, and keeps the gears lubricated. These two factors allow much finer tolerances in the machiine carving of the threads.
Rotomatics and similar designs from other manufacturers are rightly called "locking tuners." The term is much older than the fad of recent decades, possibly originating with Grover, and refers to an "anti-backlash" design of the gears, which greatly improves 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. The engineering term for such a design is "self-locking."
Today, most enclosed worm-gear tuners provide a gear ratio of 14:1. In older designs, 12:1 was common, and there were 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), so are more likely to be found on open-frame tuners.
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 have become widely available (particularly from Grover), and the Gotoh 510 offers 21:1.
STANDARDS AND CLASSICS, MUTANTS AND MULES
As of early 2020, Grover offers the following to the retail market.
102 Original - 14:1, 6:00 screw ear
102-18 Original - 18:1
102V Milk Bottle - classic shape
103 Milk Bottle - pearloid buttons in split collet
104 Super - big deco buttons
305 Mid-Size - smaller for 12-string; 7:30 screw ear
205 Mini - 7:30 screw ear, smaller button
ORIGINS OF THE TUNING MACHINE
The geared stringed-instrument tuning mechanism -- guitar tuners, machine heads, tuning buttons -- first appeared in the late 1700s, when cittern maker John Preston is often credited with a linear-pull tuning machine.
The next major evolutionary step was when Austrian luthier Johann Georg Stauffer (1778-1853) created the worm-and-gear tuner. The "Stauffer-style" design was brought to the United States by Christian Frederick Martin, founder of Martin Guitars (1833). Over the next century, the worm-and-gear design all but pushed out the use of friction pegs in guitars, banjos, and mandolins, but the fundamental design was virtually the same from one manufacturer to the next.
John Kluson established a Chicago machine shop in 1925, specifically for making tuning machines, with the "Kluson-style" design having each mechanism enclosed in a stamped-sheetmetal shell
Albert Deane Grover (1865 — 1927), born the son of a Boston piano maker, was a banjoist, composer, teacher, and prolific inventor of musical parts and accessories for stringed instruments. He was a founding member of the Boston Ideal Banjo, Mandolin and Guitar Club. Grover held over 50 patents for musical instrument parts, and founded the musical accessories company A. D. Grover & Son, which in 1952 became Grover Musical Products, Inc., of Cleveland, Ohio. The company he founded continued to refine the machine-head concept through the 20th century, as with their open-frame Sta-Tite tuners, still widely copied as "Waverly" tuners. But Grover's most lasting accomplishment was a mid-century design with the mechanism sealed in a cast-metal shell.
THE ROTOMATIC
The Grover Rotomatics were a commercial game-changer, and became original equipment on better-quality guitar models of a couple dozen brands, from the 1960s through the 1990s. The "shell" both protects the mechanism from debris and corrosion, and keeps the gears lubricated. These two factors allow much finer tolerances in the machiine carving of the threads.
Rotomatics and similar designs from other manufacturers are rightly called "locking tuners." The term is much older than the fad of recent decades, possibly originating with Grover, and refers to an "anti-backlash" design of the gears, which greatly improves 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. The engineering term for such a design is "self-locking."
Today, most enclosed worm-gear tuners provide a gear ratio of 14:1. In older designs, 12:1 was common, and there were 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), so are more likely to be found on open-frame tuners.
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 have become widely available (particularly from Grover), and the Gotoh 510 offers 21:1.
STANDARDS AND CLASSICS, MUTANTS AND MULES
As of early 2020, Grover offers the following to the retail market.
102 Original - 14:1, 6:00 screw ear
102-18 Original - 18:1
102V Milk Bottle - classic shape
103 Milk Bottle - pearloid buttons in split collet
104 Super - big deco buttons
305 Mid-Size - smaller for 12-string; 7:30 screw ear
205 Mini - 7:30 screw ear, smaller button
| Row 1 column 1 | Row 1 column 2 | Row 1 column 3 |
| Row 2 column 1 | Row 2 column 2 | Row 2 column 3 |
| Row 3 column 1 | Row 3 column 2 | Row 3 column 3 |
| Row 4 column 1 | Row 4 column 2 | Row 4 column 3 |
| Row 5 column 1 | Row 5 column 2 | Row 5 column 3 |
| Row 6 column 1 | Row 6 column 2 | Row 6 column 3 |
| Row 7 column 1 | Row 7 column 2 | Row 7 column 3 |
