MECHANICAL RECORD / 006
Powered by you.
This exhibit explains an automatic winding system using the Magic Lever principle. It is a teaching arrangement, not a reconstruction of a particular Seiko, Rolex or other caliber.
Why it moves this way
A rotor supplies relative rotation. An off-center pin makes a two-pawl lever reciprocate. The two tips alternately push and pull the transmission wheel, so either direction of rotor movement can contribute to the same winding direction. Reduction wheels then drive the barrel arbor.
At the winding limit, a slipping outer attachment allows further input without increasing spring tension indefinitely. The barrel cover is removed here to expose the spring.
What is simplified
The rotor follows a prescribed demonstration swing or your direct input. Wrist inertia, gravity, friction and contact forces are not solved. Teeth and flexible pawl tips are illustrative; the gearing layout and ratios are not a production design. The spring shape and slipping movement are enlarged for reading.
The 0–100% charge scale is compressed for teaching. It does not predict winding efficiency, number of wrist movements or power reserve. The timekeeping train is omitted, and charge is retained for inspection. Exploded parts remain synchronized but are not in operating positions.
Sources
Horopedia · The slipping attachment ↗
Reviewed 15 October 2026.
← Back to the exhibition