My understanding of gyroscopic procession comes from a demonstration in college freshman Physics class. A student is holding a spinning unicycle while sitting on a swivel chair. As he changes the axis of the spinning wheel, his body would rotate on the swivel chair. And I only remember the right hand rule. Assign right thumb to the spinning wheel axis, align the right index finger to the axis of the disturbance torque, then point the right middle finger downward to get the axis of resultant torque. For the plane w/ spinning prop up front, the thumb would point foward to the nose of the plane. Then a pitch-down disturbance motion (with axis of rotation aligned to the wing tube) would align the index finger to the left wing tip. Then middle finger pointing upward toward canopy would dictate a torque yawing plane to the left. So as the tail dragger pitches up during take-off while the tail lifts, it would cause the plane to yaw to the left, right? The take-off yaw-left effect I've seen is most severe in Cub. I am not sure if it's caused by something else.