So now, I'm at a loss for my current problem. I swapped out my original two-blade rotors for replacement three-blade rotors (my 'D' model upgrade). Everything fits properly, the rotors are oriented correctly (leading edges spinning in the proper directions), and spinning freely, yet things are irratic on launch. When I throttle up, the quad will try to fly backward, sometimes off to the right or left (while flying backward). If I replace the three-blade rotors with the two-blade ones, everything returns to normal. There is no binding of the three-blade ones. None are unusually loose, none failing to spin. No noises indicating a gear failure or motor failing either. I find that it takes adjusting the throttle for forward flight before lifting off, to compensate for this, which I don't think I should have to do.
