“I look at the world and I notice it’s turning
While my guitar gently weeps
With every mistake we must surely be learning
Still my guitar gently weeps”

-“While My Guitar Gently Weeps,” George Harrison (1968)

George Harrison’s guitars, and many other string instruments, use a worm gear drive. While more than a half-century has passed since The Beatles hit American airwaves, their music continues to influence generations.

Where is the Worm Gear Drive on a Guitar?

A worm gear is a specific gear composition in which a screw (worm) meshes with a gear/wheel. It is a simple gear comprised of a cylinder or disk with teeth that project radially. The purpose of a worm drive is to reduce rotational speeds or produce higher torque.

Worm drives have three types of gears:

• Non-throated worm gear: Gears without a groove, or throat, machined around the circumference of the worm or worm gear.
• Single-throated worm gear: A throated worm gear with concave helical teeth around it.
• Double-throated worm gear: A gear in which both gears are throated with concave teeth

In guitars and other string instruments, you’ll find a worm gear at the machine head’s tuning knobs. These knobs tighten or loosen the strings, which is essential for tuning. Once you tune a string, the gear holds it in place so it doesn’t loosen.

In guitars, the worm appears to move side to side. This causes the worm wheel’s teeth to move in a circle, similar to a Falk gear. If the gear wheel tries to push back, the direction it pushes is perpendicular to direction of the gear’s rotation. The friction coefficient between the gears results in the frictional force matching the rotational force. In other words, the worm and worm wheel move at the same speed, resulting in no net rotational force.

Most guitars, banjos, double-basses, bouzoukis and other string instruments use a worm gear for the tuning mechanisms instead of friction heads, which violins use. The main reasons for this are the gear’s force reduction, like a Falk gearbox, and locking capabilities. While most worm gears only turn in one direction, those used on instruments turn in opposite directions.

How Gears Rocketed The Beatles to Stardom

The members of The Beatles were talented songwriters and their guitar work was groundbreaking. When they emerged on the scene, the country was in a transition period and ready to change. The sounds the legendary rock band produced had never been heard. The music was happy, exciting and loud for its time. The band popularized the two-electric guitar sound and broke down the barrier between music for adults and teens.

Once they broke down that wall, The Beatle’s music was seen more as art than noise. It also influenced other types of cultural expression, creating a personal and cultural revolution in human history. Harrison’s sweet lead lines in “Something” displayed confidence. In “Lucy,” he offers a dynamic melody with a blues-like restraint, producing a new guitar sound. In “I’m Only Sleeping,” Harrison used a pedal and recorded his guitar solo as the tape recorded in reverse, creating a deep, dream-like sound that musicians continue to emulate.

The bright, bold tones The Beatles produced paved the way for musical innovations. Without a worm gear drive, the musicians would have had to risk their guitars becoming out of tune in the middle of a song. Thanks to the reliability of their instruments, The Beatles’ music transcended previously unbendable cultural and musical barriers, and continues to make waves today.

Posted under Falk Gearboxes on Thursday, November 16th, 2017