If it’s a Y vibration then look for loose items like landing gear or antennas that are bouncing. Also look for a wire or something that is either bouncing on the FC or pulling on the FC as it moves.
Thank you Allister, I will check the security again. A thought, could it be something as simple as bad calibration of the accelerometers with respect to level or some such. I will double check. Just that the vibration seems to match the other two and simple be offset.
Indeed due to it being my first attempt with a flight controller (replaced the 3GX) I do have a lot of wires hanging around. At least now that I know it flies I can try height hold or position hold so that I can better view what’s going on (rather than the constant panic). Many thanks all, I’ll let you know the results.