Safety First: Avoid the Prop Arc!

Even carbon-fiber and glass-fiber-impregnated composite propeller blades can develop microscopic hairline fractures after a lot of use and some hard landings. We’ve seen a case where a composite prop mounted to a brushless motor spinning at a high RPM flew off a test stand and speared the roof of a workshop! Two primary forces act on a prop spinning at high RPM: (1) the strong centrifugal force pulling the propeller blades outward from the rotating...