Somehow this thread seems to be more and more investigative DIY. Sustained flight being the difference more or less. Trying to
use a PC cooling fan aka Boxer Fan blade unit will be a greater disappointment than purchasing a cheap edf.
The shallow pitch of the PC fan...yields less than exciting results. Its either high pitch for greater volume per minute or diameter
to increase FSA and proportional 25% of a blade responsible for most of the bite.
The greatest effeciency so far has been witnessed with helix blades, helix stator mounts and stator sets...by Stu Maxwell. The
magic will occur when someone invests in high pitched smaller diameter helix blade sets driven by the newer motors. This will
permit us to utilize many more existing fiber glass fuselages originally created for recip ducted fans.
Nothing wrong with DIY and the like... Things are well beyond that point today for not any real $ differential to traditional r/c