Dave
Quote from your link: "Musings on the single-blade rotor and 1P vibration."
This text indeed contains some of the scenario's of what can go wrong, first order oscillations in all directions.
In the horizontal plane because of the non vertical lift,
but also vertically (even if one would allow elasticity or hinges as the text suggest), because even if the system allows easily to construct an inertial equality, by design there is no aeroDYNAMIC equality, so flapping will also create vertical vibrations: there is no blade going down to compensate the up going blade loosely speaking, even a hinge still transmits vertical forces.
Rotors are quite complex dynamic systems....
Looks like a hell of a job to get that fixed...
d3
Added : scaling changes dynamic behavior quite a bit. A RC model will show mostly qualitatively similar effects, but quantitatively quite different because length, mass, surface, weight, strength etc doesn't not scale equally and this will influence resonance and vibrations quite a bit. So at the speeds shown vibrations could be ok for the RC model, but this will no longer be so when going full scale.
Last edited by delta3; 4th January 2011 at 22:51.