i did not realise that the black plastic part of the ball link, the hole is bigger one side than the other, so if you put them on the wrong way they will seem very tight then when have been flying for a while the smaller size will be the same as the larger side and they become very oversize. this could lead to it just poping off when you dont want it to. just a thought i have checked all mine and all those i was not sure about i have replaced.
