I have a problem with a voyager e the heli lifts from the ground and about 30 seconds into a hover the tail apears to be moving up and down violently to the point were I have to bring it down asap. I have checked the pitch it is -5 +8 +12 as per the manual the throttle curve is ok also I have checked everthing that I could think of and have not solved the problem. Am I missing something? Any advise would help. I am not new to helis although this is my first electric and I have not encountered thi problem before.