Main rotor and archimedes’ screw: what they have in common

1. Step 1. Main rotor — is part of — Autogyro. A main rotor.
2. Step 2. Autogyro — has part — Propeller. A tractor propeller.
3. Step 3. Propeller — evolved from — Archimedes’ screw. The first propellers by Smith and Ericsson were a variation on the Archimedes’ screw.

Open Evothings