ORIGINAL: tintrax
Three degrees positive incidence on the rotor blades relative to each other is mentioned - that would result in the rotors spinning the wrong way! Negative incidence is required - note that lift is still generated due to airfoil section. I find simple rotor hub made from 1/8th ply and polypropylene hinge is fine - cheap and simple to make. I now always have a 15 degree `delta` angle so that blades are made set at zero incidence which adusts itself in flight.
If you are using a "clark y" type airfoil, zero incidence is several degrees (4 or 5 depending on where you measure)
positive angle of attack. If the zero incidence is the flat bottom part then you may have 7 or 8 degrees positive angle
of attack.
I'm not using delta 3 hinging so I set my blades at -4 geometric incidence, this being 0 actual angle of attack.
mickey