Give the rotors a slow RRPM and have a slightly greater pitch on the so-called advancing blade so that the rotors create a wing with some dihedral.
Partial UniCopter.
Knife-edge leading edge will probably cause blade stability problems and radiused trailing edge will be detrimental to lift in forward flight. Perhaps a compromise like the CarterCopter might help.
See small mockup.
Rotor:
Angle between masts is 18º. The stagger is 27". Twelve blades per rotor. Rotor radius is 8 feet.
At the blade roots, there is only 1.1458" vertical distance between the centerlines of the blades of the two rotors at azimuths of 30º and 60º.
At the blade tips, the minimum vertical clearance is approximately 3.8013". Assuming NO blade flex and a tapering toward the tips, this will work.
Blade:
The carbon skin has the fibers running spanwise and chord-wise, without any diagonal plies. This will allow the blade to be twisted at the tip about the pitch axis while the root of the blade is held rigidly by the hub. Pitch may be changed by a carbon tube with diagonal threads running down to the tip or buy some diagonal expansion device in the blade.
Power Train:
The two disks are interconnected by two large ring gears. These gear will offer little or no drag in climb or in forward flight because if the partial lift of the blades.
Give the blades on the retreating side (lower blades) a slightly greater pitch than the advancing side(upper blades). This will mean that in hover the blades on the advancing side and the blades on the retreating side will have the same average angle of attack. Also, this will mean that in forward flight the blades on the advancing side will have a greater angle of attack than those on the retreating side; and this will give
Perhaps there should be twist so that the outer portion of the lower retreating blades, which are outside the downwash of the upper advancing blades, does not have too large an angle of attack.
