I have an E-Flite MCX which has recently started to drift in little (2') circles when I try to hover. The nose is always facing the same direction, but high, low, wherever I go it looks like it is revolving around an unseen point. Since I'm just beginning with helicopters, I have broken and replaced upper blades, lower blades, the fly bar, head and even the landing gear(!) but the flight problem seems to have crept in somewhere along the way.

As I'm getting pretty skilled with the MCX, I bought a Helimax Novus CX (same as Walkera Lama II) and it does the same thing out of the box only the circles are about 6' across. [] I wanted to adjust the gain, but don't want to get it more out of whack until I have a better idea of what is causing the circling problem.

Any ideas about what I can do to correct this?

Thanks,
Jason

PS. Another thing I noticed about the MCX that has only started to happen recently is that as the battery gets low (last 20 or 30 seconds of flight), the heli starts to pirouette loosely to the left, tail following the nose in a spiral. I just land and turn everything off, but I'm wondering if one of the motors might be wearing out. If so, I guess I should replace them both, right?