SF props - RC Groups
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Jan 22, 2013, 05:58 AM
Corflute Codger
flymess's Avatar

SF props

I know they are wider and rounder than "normal" props, but does anyone know how they actually work to make them SF. Is it more torque because of their shape? I expect so.
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Jan 22, 2013, 06:17 AM
christian theme park operator
H2SO4's Avatar
They were originally meant for use with reduction drives - gearboxes. Before the brushless motor and the inrunner/outrunner technology distinction made its way into RC flight, electric brushed motors were mostly of the high-revving low-torque variety. A gearbox was sometimes employed to turn that around, and a "slow fly" prop was more suitable than the thin bladed variety.

Nowadays, with gearboxes essentially consigned to history by the brushless outrunner, the line is blurred since a motor can be wound to produce just about any combination of kv and torque. Slow fly props give more thrust at a given rpm, at the expense of greater stress and current draw. Whether they're worth it depends on the application. There are no absolute rules (except "don't smoke your motor" ).
Jan 22, 2013, 06:45 AM
Corflute Codger
flymess's Avatar

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