Hi, I'm new to the forum and new to quadflyers, so as a starting point I bought a second hand UFO5 to get used to quadflyers. It flew OK for the first couple ofweeks, although I couldn't get it to hover, but now it has developed a permanent spin. All of the motors seem to be working and I've tested them for thrust byholding the UFO in my hand and increasing the revs. Nothing seems to be burnt out on the board, so I wondered whether anyone on here has any ideas. One thing I have noticed is that when under load the cross pieces rise upwards and that two of the rotors seem hesitant at first. Is this normal?