Originally Posted by
heliduck
The OP never asked for information on gimballed or stiff in plane engineering, he/she asked if anyone had used a constant velocity joint instead of a universal. The star flex arrangement is a constant velocity joint.
Except you don't use a constant velocity joint, or any angular joint at all, unless you have a stiff-in-plane gimballed rotor. In all other cases the hub is rigidly fixed to the mast and the angular changes for the rotor thrust vector are performed through discrete hinges or flexures along the blade axes.
As I said, no change in angle between driving and driven elements - ergo not a CV joint
Agreed, this is precisely the point. There is no angular joint between the rotor hub and the mast whatsoever with starflex, constant velocity or not.
Nobody would consider a wheel bolted to the end of a straight rear drive axle on a truck to be a "constant velocity joint".