RE: Rotor head ideas
Hi,
From what I can see, it has a teetering rotor head just like full-scale (Bensen style) gyros. The teetering motion is what equalizes the lift of the blades as they travel forward/backward respectively. Typically blade tip weights are used to tame the "following rate" to make it controllable. Emilio Cabezas in Spain and others have experimented with this.
//Ulrik