To: Try_Cyclic
The real cause is that the blades will flap into position more quickly when there is coupling between pitch and flap.
This is the case in the full size R-22
When the R-22 blades flap, pitch is pulled out or addded since the pitch links are not on centerline. This alters the way precession affects the blades. Precession does NOT always work at 90 degrees. It is taught that it is always 90 degrees as a simplification.
The 72 degree swashplate offset exactly compensates for the non 90 deg. precessional response and the result is that the R-22 rotor follows the direction of the cyclic stick in a normal fashion.
Maybe Frank Robinson will post on this sunbject and shed more light on this issue.
The coupling effect you describe is common to all helicopters and is referred to as pitch coupling. Under ideal circumstances if the pitch horn on any helicopter were coincident with the teeter hinge or the centerline of the flapping hinge there would be no coupling. However in the real world this is not always true. Yhe pitch coupling is similar in effect to that of a delta hinge tail rotor. When the tail rotor blade flaps the pitch will change fron that input by the pilot. The purpose of this is to equalize the lift on the tail rotor blades and minimize the bending forces on a two bladed tail rotor. The blade going into the wind will flap so as to reduce the pitch and the retreating blade will flap so as to increase the pitch on the blade. On multi blade systems the blades flap individually but not to minimize bending forces. Getting back to one of my original posts about lead/lag being a result of flap, the tail rotor on the CH-37 had a fully articulated tail rotor that could both lead/lag and flap.
Maybe Frank Robinson can better explain how his system works but I also hope that he can explain how he and his engineers were able to defeat the laws of physics. If he can, then I will be the first to say that I was wrong.
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The Cat