I keep seeing people claiming that a lower CG, relative to the prop plane, results in a more stable copter. Does anyone have any science to support this? Interestingly, rockets are LESS stable when the CG is below the rocket nozzle, and I wonder if multicopters would react similarly.
Also I see many copters designed with dihedral (props canted in). I can see how this would help in relatively still air, but it seems like it would introduce unwanted cross-coupling in wind and turbulence? i.e. a lateral gust would induce a pitch/roll moment instead of a pure lateral translation.
Intuitively, I would think you want the props and CG co-planar.