Hi Rob....

For what it's worth....some years ago I experimented with the tandem dual rotor arrangement of "AL's Autogyro". My results were less than pleasing. For some reason both rotors simply would not spin up equally. Reversing the rotors (putting the top one on the bottom and vice versa) didn't help either. One would always be lazy. I don't remember whether it was the top or bottom rotor. In other words, it was the position of the rotor that made it lazy.

My suggestion would be to go to a single rotor, with four flapping blades with 10-12 degrees of "Delta 3". Tilt back and engine thrust angle suggestions from "SpinDizzy" seem about right to me.

Bill