Running a #36 with 1800mAh LiPo, brushless motor and metal head conversion.
Finding vertical stability a problem. Small rudder input causes a sudden drop or lift a fraction of a second later depending on left or right.
Nose right causes a drop and nose left causes a jump up.
This is also worse because trying to bring the heli back down causes a sudden drop with almost no input at all on the collective.
I have the similar rudder sensitivity in a stock #36 but not the erratic control in collective.
I was wondering if its slop in the linkages causing a "flipping" effect in at the main blades.
Any body have this before?

Cheers
ViciousHeli