I have had several brand new Axe CP V3s wobble, start off smoothly, then start to wobble like the main shaft is bent.  To stop this you need to replace the o-rings in the center hub that surround the feathering spindle (assuming your main shaft is not bent ;-).  You can mess with the pitch knob and make it a little better but you pretty much have to replace the o-rings.  It's ~30 minute job, maybe a couple of hours if you have never replaced a blade grip or feathering shaft.  You will notice the old o-rings will be firm and stiff, I'm guessing old stock that dried out.  They are so hard they no longer dampen vibrations like they are supposed too so the heli starts smooth then progresses to a violent wobble....yes, it can be violent.  I doubt I will buy anymore new Axe CPV3s, if I did I would get a set of o-rings just in case.  My last one came two weeks ago with a bad wobble, new o-rings fixed it just like the first one (which took along time to figure out). 

Happy flying!