Hi Tintrax !!! Virtually every modern gyroplane uses a two-bladed teeter head, so there is no question of its stability and usefulness. It is very easy to build, and even easier to balance than a 3 or 4 blade head. I started my early gyroplane experiments (teeter head) by using a Bensen-style stick fuselage with a forward mounted KB .40 and 3-channel control. Rotor tilt was used for pitch control. Weight was 4 1/2 lbs. I used rotor blades that were built up, like an airplane wing. They had a plywood spar at the attachment point. The total span was 63", and the blades were very thick at 7/8". Chord was nearly 5". They spun up very easily and had great lift. They also made an incredible "whopping" sound, just like a full-size heli. I used a semi-symmetrical airfoil with a slight reflex. I had no experience in flying gyroplanes at that time, and had difficulty getting the model unstuck from the ground. When I finally held full back stick on takeoff roll, the model leaped into the air at a 45 degree angle !!! I was astounded and could only chop the throttle, watching my model float gently down to earth. The rotor tilt was giving me problems (engine seemed to overpower it), so I played around with different arrangements, cut down blade size, and got further and further away from success. I was not aware of the offset gimbal at that time. I finally went to smaller, lighter models with twin rotors and had great success with those. There is a real potential for this arrangement, however. I still use the two bladed teeter head on my control-line gyro. If you want to try a teeter head, there are only a few things to keep in mind. First, tail clearance is of the utmost importance. The blades should tilt @ 5-10 degrees to each side. Teeter stops must be built in to prevent excessive teetering and tail strikes. Allow for extra room for blade "bounce" upon landing. Secondly, keep the teeter pivot bolt slightly above the plane of the rotor blades for stability. A slight amount of coning angle may be helpful. Thirdly, you may want to try using slightly thicker airfoils and maybe wider blades to compensate for the loss of blade area. Rotor will spin up easier and rpm will not need to be as great with thicker airfoils. Blades do not need to be as heavy duty as heli blades. They are not under nearly the same centrifical force as on a heli. I have flown my twin rotor gyro with a single 2-bladed rotor (please see my photo gallery for a pic) and performance was similar to the twin, but it flew a bit faster. I was using flat pieces of basswood with slightly rounded edges, and much better performance can be gained by using thicker airfoiled blades. I still have the teeter head for it, and would like to try more experiments. Maybe now's the time !!! One more thing, be sure to balance the teeter until it is level, and make sure everything operates very freely. And, as with most gyroplanes, the taildragger stance is preferred in order to allow more air to go up through the rotor on the takeoff roll. Good luck to you and to all who wish to further the gyroplanes' capabilities. Happy flying !!! Charlie Anderson