Observed arrival · 2026-09-20
Four Sails
A compact technical guide to the sails, cap, millstones, and winding gear of a traditional windmill.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Windmill enthusiasts, restorers, and curious mechanical historians
- Worth noticing
- The page traces how a small fantail turns an entire cap against the wind through layered gear reductions.
Field notes
The guide follows the mechanical sequence from wind capture to cap alignment and grain grinding, giving each component a plain-language definition. It distinguishes spring sails, whose hinged shutters can be adjusted from the ground, from canvas sails reefed by hand. The winding section specifies a four-stage transmission—bevel gear, long shaft, worm gear, and spur wheel—that converts the fantail’s motion into slow rotation of the cap.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue