crab,
This simplistic idea is intended for the recreational (homebuilt) helicopter. The objective is to provide low hour pilots with a slightly more responsive cyclic control, then they now get from a teetering rotor.
Just trying to reduce the 'safe ~ homebuilt' oxymoron.
Nick,
Thanks for the technical critique. To clarify the idea, sketch C/ is just a slight elaboration of the previous sketch B/
The 'undersling' on sketch C/ is what
hopefully differentiates this hub from that of a normally articulated rotor head. I believe that the teetering rotor works because the two blades' centers (of mass, lift, drag percussion etc. etc.) are basically inline with the underslung teetering hinge, during normal flight conditions. This condition also exists in sketch C/.
In addition, if one blade on sketch C/ flaps up 5-degrees and the other blade flaps down 5-degrees, this centerline still passes through the 'Virtual center'. Therefor synchronous flapping on rotor C/ should be the same as the teetering on rotor A/. Many moons ago you mentioned that the mast absorbs the small amount of lead-lag in a conventional teetering rotor. Theoretically, this should apply to sketch C/, as well.
I wonder if there might be a vibrational problem. The two-blade configuration may result in a 2P vibration when the rotor disk is not normal to the mast, whereas three or more blades should not.