Hardyus: I looked into tilt sensors but they are useless here because they can't tell the diference beetween gravity and acceler ation. If you draw the forces in a simple diagram you will realize that the tilt sensor will always think that the DF is horizontal because; whenever the gravity is tilted, it creates a sideways acceleration that counteracts the tilt exactly!. Tell me if you want me to draw the diagram, i dont' have the time right now.

ADI: I agree with you, it is better to do some physical damping first if possible. However, I'm sure that the original DF uses software or/and hardware filtering (as they use analog gyros a simple analog R-C filter could work). However, I never said it's impossible to fly without the dampers; but the movements are somewhat more "jerky".

Another thought: For those of you that use off the shelf motor drivers; they normally limit the acceleration of the motor to preserve the gearbox. This is in fact acting as a low pass filter because very rapid transients are not allowed in the motors.