Constructing NACA's (later NASA) wind tunnel propellers in the 1940s. 2:42 video.
https://www.youtube.com/watch?v=XTONzTs53VI
Previously:
https://www.homemadetools.net/forum/...767#post170965
https://www.homemadetools.net/forum/...661#post170566
https://www.homemadetools.net/forum/...962#post168026
https://www.homemadetools.net/forum/...2518#post96512
https://www.homemadetools.net/forum/...136#post145451
