I'm having trouble with altitude-hold while in autonomous mode. The system doesn't respond to a drop in altitude.The system recognizes when altitude increases: the servo rotates the props upward to bring blimpudino back down.  However, when altitude drops, the servo doesn't react at all; it just keeps the props in the "straight-ahead" position.The servo should point the props downward to bring the blimp back up to the starting altitude.There's no mechanical binding with the servo or the props…See More