Kevin mentioned surprise that I wasn't using prepreg.
Most homebuilders do not, especially when building
to plans.  Prepreg is mostly used in mass production,
as far as I know.

I don't remember exactly why Bill Freeman settled
on 72" in diameter, I think the assumption was that
it could be used on more airplanes. It was also
designed to absorb 250 HP, so the blades have a
large chord.

The test blades are being built for rotation opposite
engine, tractor.  This certainly won't be a "one-size-
fits-all" blade.  There will have to be many variations.

Perry

Maybe not that many with a variable pitch. Unlike a metal prop
it is safe to cut the diameter down as carbon fiber has a far
higher tensile strength to weight ratio than aluminum and much
better fatigue characteristics.

Paul Lamar

The fellow who developed the American Aerolight and a later 2 place
canard lived in Albuquerque and worked with a company that did
helicopter blade work..  He developed a composite blade that was super
tough by injecting something into the closed mold after the carbon fiber
blade surfaces had been laid up and the molds bolted together.  Don't
have any other details but will continue to search for his name and
other details.

Roger Robertson

What is usually injected into that type of mold is syntactic foam
which is a fancy word for epoxy and microballons.

Paul Lamar

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