Tailrotor strong vibration at mid rpm

[corytan]

hi guys,

my heli is a 90size, EP dualdrive torque tube setup. When i run the tailrotor, at around 40-50% throttle, vibration of the tail is very very strong, enough to numb my hand bad.

When i remove the tailrotor blades, there is mild vibration, then close to zero vibration at 100%.

Blades are 1set of NHP carbon.

Any advice for this super heli noob?

[SKYHOBBIES]

Check the tensile strength of your torque tube... for hairline and distorted gear mesh.
Secondary suspect is as usual unbalanced tail blades or slight bent on the tail shaft...

Cheers!

[vintcs]

which heli u fly?

[xuen7]

hey dude i know this may sound strange and doesnt make sense.. but i am guessing your heli did not come with original carbon tail blades right? well, i am right just change your blades back to the original plastic blades and the vibrations should be gone for good..

update and let e know see how it goes... thanks

[corytan]

xuen, it was delivered with carbon blades.

vintcs : minicopter maxijoker 3DD. I don't fly it yet, coz i'm a noob at flying helis. i'm building it for someone else to fly.

[corytan]

Check the tensile strength of your torque tube... for hairline and distorted gear mesh.
Secondary suspect is as usual unbalanced tail blades or slight bent on the tail shaft...

Cheers!

hi skyhobbies. thks for the advise. so far the shafts appear to be pretty true visually. trying also to check for slack in the linkages.

i hope it's just reasonance frequency vibration. without the blades, when I gradually accelerate the tailrotor, from 0-40%, there is very little vibration, then at 40-50% there is mild but noticable vibration, which disappears as i accelerate to 100%.

[HotDogBun]

Just 2cents worth.
For vibrations, I always remove the entire rotor head and tail blades, then try zoom in on spot, not sure if it's what you've done.

I dont trust my eyes, usually do "shaft" replacement to be sure.
At 100% there is chance there's chances of vibration, perhaps too high frequency to feel it?

[Murdanny]

hi guys,

my heli is a 90size, EP dualdrive torque tube setup. When i run the tailrotor, at around 40-50% throttle, vibration of the tail is very very strong, enough to numb my hand bad.

When i remove the tailrotor blades, there is mild vibration, then close to zero vibration at 100%.

Blades are 1set of NHP carbon.

Any advice for this super heli noob?

has the heli crashed before?

if he has, is the vibration nodding up and down or shaking left and right ? if up and down, check your main shaft. if its left and right, check your tail shaft. i suspect its the tail shaft. you can check when you spool up, the tail shaft will wobble because its bent. cheers.

[Adrianli]

Do check the tail boom supports and landing skids too.

[vintcs]

is this heli brand new? if not, should check out this rotor shaft or the gears for smoothness mentioned by the fellow flyer. did u compare with the same heli that there similiar vibration issue.

[noob]

Hi

hi guys,

my heli is a 90size, EP dualdrive torque tube setup. When i run the tailrotor, at around 40-50% throttle, vibration of the tail is very very strong, enough to numb my hand bad.

When i remove the tailrotor blades, there is mild vibration, then close to zero vibration at 100%.

Blades are 1set of NHP carbon.

Any advice for this super heli noob?

Hi i am noob too,
Does your heli Tail produce a distinct whoom fanning sound when 40-50% throttle?