ORIGINAL: Spindizzy
Rotor Separation
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.
Sean....
That may be the reason you have been successful and I was not!! Good insight!!
Bill