MY 90se shaking come and go

[goitoibayvoi]

please be my advice
i have raptor 90 se using ys 91 . 601 gyro . 9252 servo.sab 690 blade. runing at 1860 rpm
i do alot 3d . and fly ok around . but everytime come to hover or ready to land about more than haft stick..
the heli shaking ( like chicken leg ) , the whole heli shaking . and it come and go (imtermitten mode) sometime it is not happen.
i wonder, is that because the pitch servo go bad sometime or..
please give me some idea
thank you

[RobO]

Sounds like something is out of balance, most likely the main blades. Are they balanced well? Do the blades look smooth when the heli is shaking or do they flutter?

Imbalance can ba a harmonic thing, it can appear smooth a one rpm or load and flutter if things change.