Machine head

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.

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.

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.