I'm only really familiar with the Enstrom articulated head where the flapping(coning) hinge is about 3 inches out from the mast. It is the couple formed by the distance between these hinges that gives the articulated head its control power. Thats what I was trying to get at in my last post(badly).
Agreed, if you put the coning hinge over the mast that is not an issue.
What goes on during tracking and can mis-tracking be balanced out?
Imagine an Enstrom in the hover. The thrust on all three hinges must be the same magnitude and direction (vertical) for smooth flight. Given that the blades will flap to equality, if one blade has more pitch, it will flap up and the disk will tilt. Unlike cyclic input, that blade will have more pitch for 360 degrees so the disk will wobble, which you see with your tracking light.
The thrust vector will be at right angles to the plane of the disk which will always be higher at blade with the increased pitch, hence the thrust vector will 'wobble' around the vertical at a fixed but small angle, giving the vibration which is felt as up and down bounce. This is not correctable by adding mass to the blade as that would act in the wrong direction.
What you need is the thrust vector dead stable for smooth flight and for that the disk must run true. I think it is stability of thrust vector rather than c of g/differential coning that is relevant to smooth tracking.
You shouldnt have difficulty tracking a one bladed rotor!! I don't know if the C of G changes due to coning would be an issue. I suspect not.
Its a bit of a pain to carry a large counterweight around though. Probably best make it shaped a bit like a blade.
