Has anybody tried making a flexible prop?


Yes. Warp drive makes a flexible prop with a steel rod in the middle that
twists the tips with an electric motor, to change profiles for climb to
cruise. That is one feature that had better not be copied.


I want to say that the IVO prop has this mode of operation. I have not
looked at the Warp Drive closely enough to validate what you are saying.

The IVO has some drawbacks, however. I don't believe it's compatible
with 4 cylinder lycomings (torque pulses are damaging...) and i know of
a few who have tried to use the IVO in flight adjustable prop for high
speed flight, and found it less than satisfactory. Since the inboard
portion doesnt rotate as much, it must produce some "flat plate" drag..
anecdotal reports of a 10 mph penalty on a 200 mph aircraft are what I
recall.

For the slower planes, this may not be an issue..

Dave