Rotor Separation

Interesting statement there regarding rotor separation. It would appear that when Al was designing and testing his gyro design he found a simple way to achieve good separation without having to move the two hubs too far apart. Its hard to see on my photos I posted but the separate rotor hubs used different dihedral angles for the rotors. The lower two blades had an internal angle of 186 degrees with the upper having a much reduced internal angle of 172 degrees. This gives a very large separation well in excess of 1 1/2 chord width by the time you get halfway out along the length of the blades. I must also add Bill that the aforementioned co-axial gyro re-kitted itself spectacularly one fine day when my complacency far exceeded my flying ability.............good design though

Bill, the plus one figure I stated is not precise.I used a flat bottom rotor section which by the definition of incidence does give around +1 incidence ,however, I have never succeeded in getting a rotor to start and move in to autorotation unless the blade undersurface has at least a small amount of negative angle relative to the rotational plane. One exception is my Jim Baxter type delta hub with its blades mounted with the falt bottom flush with the tangs in flight this probably gives a slight negative angle when taking coning angle in to account. All my gyros use a single mounting bolt on each blade so I can angle them forward for simple starting even in no wind. I think it was an idea first pioneered on models by Georges Chaulet.