tail fin vibration .stratus os 91szh ps open tail gear

[goitoibayvoi]

i have stratus use 91 os szh ps.mp2.( open tail gear ) i have very bad vibration (but not happen in close tail gear)
even idle on groud.
when i hover even wrost .. the tail fin move so much and sometime the crew come loose.
any idea will be great . and where do i look for
thank you for reading my post

[WayneBrown]

Check for a bent output shaft on the tail.

[Gary O]

I had a similar thing happen with one of my Tempest FAI machines. It had been smooth as glass and the heli has never been down or even landed hard. I took the tail shaft out and checked the runout. Somehow it had developed enough runout to cause the vibration. New tail shaft, problem gone.