So, I had a couple of little accidents with my newish CP2.
I've replaced all the broken parts and am now trying to tune it so that it's stable.

I ran up the rotors just a little way and one was higher than the other, so I changed the collective arms so that they span in the same arc.
So far so good.

But spinning it up further, closer to take off, it gets a really nasty vibration, and the rotors are not balanced again. The shaking makes the whole heli wobble.

Any advice on balancing it? My experience is limited, so use litte words only please :-)

Cheers, imo.

Hi Imo, Check that the feathering ( spindle) shaft between the blade grips is not bent, if not make sure that the main shaft is straight as well. These are common causes along with unbalanced blades that will cause unwanted vibes. You may have to remove them to check them properly, any slight bend will cause problems. Usually spinning the feathering shaft with a alllen wrench or such while it is still installed will show any bends with wobble in the blade grips. Inspecting the main shaft sometimes requires removal to check for them. Hope this helps you out.

Thanks, I think the spindle is ok because thats one of the things I've replaced. Not checked the main shaft tho.
I'll report back in a few days after I've had time to remove it.