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Old 04-03-2008, 11:21 AM
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Default RE: 1/2A ducted fan???

So if we know the 120mm duct (5") Clancy Tubo Bee worked with a 074 & fatblade 7pitch,
and the EDFs are 40/50/64/75mm with lower pitch & rpm out of our range,
how far down can we go from the Clancy toward the 55mm EDF.
Especially for a SureStart.... didnt I see they were only ballpark 30-40watts somewhere?

Looking at it from a wattage side,
a 40w electric motor would only try to spin ~50mm EDF
(gws brushless 55EDF ~ 40w @ ~20krpm)

The nice thing about trying to make a 4blade from cut 8x4 - 9x5 is the large hub would still have a lot of meat left after the notch thins it by half. I wouldnt trust a half thick 8x4 on a .15, but how hard can a SureStart torque spike all that hub meat still left on the prop.
3x5 FourBlade in 75mm duct, 1.5Spinner, with cheeks & tail for the engine - worth a shot