Originally Posted by edi
your posts are just great!! Please keep them coming, I find them extremely instructive and well written.
A question about the relationship between flapping and coning: Doesn't flapping rotors allow for more coning automatically? In other words, if you don't allow coning, won't the flapping be gone, too?
Perfect conclusion! Yes this is entirely true, allowing one generally allows the other. However you can arrange flapping with lower coning by choice of RPM and blade weighting. So it's possible to have flapping with fairly low coning. But keep in mind, that if you have cyclic feathering (spindle tilt or swashplate) you don't need flapping in the first place. Cierva used flapping because he didn't have cyclic feathering.
This has been a problem with model gyrocopters for a long time, probably delaying their development. Modelers misunderstood this relationship and also did not understand that flapping and feathering accomplished the same thing. So older gyro models had flapping and feathering combined with high following rate (also misunderstood). What resulted was a very unflyable model.
Perhaps I'll deal with this combination next.