X50. "wo wo wo" sound when you flying..?

[TmMugen]

Wondering why. I am on the stock tail, stock main blades. The "wo wo wo wo" sound is really disturbing!!

I was told by the guys that this is perfectly normal.

Any tt rep can explain?

With practises in SIM, you can 3D too!

[carlos]

Haven't heard that one before

[don71]

Mine does that when the tail gain is just a little to high you cant see the tail move but you sure can hear it.....

[heliman5]

Does your main gear have up and down play?

[TmMugen]

I got no play in the main gear up and down. I kind of sense that the sound is coming from the tail.

Gyro gain too high? I dun think so, because if i lower my gain a further more, it is not holding..

[TmMugen]

Ok guys I found the cause!!

It is the stock tail blades that is the problem. I changed to KBDD n the wo wo wo sound is gone..!!

[RaymondJ]

I'm glad you figured it out! I still dont know what the wo wo wo sound is though, any video?

[crashburn]

Hi,
It seems Ihave the same type of noise with my X50 torque tube version.
The noise appeared arround the 2000 rpm.
I have change the Tail blade ( Align, and Curtis) but no improvement.
It is like if the torque tuque was in resonance, I will check the torque tube bearing,
The second way, I will check is the tail grip bearing.


Is any one has an idea to help me ?


Regards,
Xavier

[DavidTan]

Originally Posted by crashburn

Hi,
It seems Ihave the same type of noise with my X50 torque tube version.
The noise appeared arround the 2000 rpm.
I have change the Tail blade ( Align, and Curtis) but no improvement.
It is like if the torque tuque was in resonance, I will check the torque tube bearing,
The second way, I will check is the tail grip bearing.


Is any one has an idea to help me ?


Regards,
Xavier

I had similar issues changing to Titan SE plastic grips to try, will update on changes.

[TmMugen]

My tail is just not holding..if I up the gyro gain, the tail wag..

[crashburn]

The issue is not linked to Gyro gain, I have tried to reduce as max as possible the Gyro Gain or increase it and the resonance is still present.

Xavier

[carlos]

Just curious. Are the problems with the TT version or Belt version

[WessCo]

mine is belt with the "wo wo wo" problem.

[NitroAl]

Loosen the bolt through the one way hub 1/2 to 1 turn and see if it gets better!
The earlier raptors do it if you over tighten the bolt because it distorts the base of the belt drive gear but I have not seen it since the introduction of the shouldered bolt with the Titan SE. I would also check the gear on the tail shaft for out of round because it is the tightest turn for the belt to get around. I would check the idle rollers too although less likely to cause the Wah Wah's or wo wo wo's

[crashburn]

I have already check this point( main gear bolt).
Just to give a detail mine is a Torque tube, and the noise is similar as a Bumblebee.
The noise is not present from the engine start to the 0° (pitch) equivalent to 55 % of the engine. Above this engine limit we can heard the noise.
I have already re-check the main blade tracking.
If ou have an idea, you are wellcome.

Regards,
Xavier

[helicopter1]

Might be the tail servo linkage vibrating?

[crashburn]

I have already replace original plastic guide thunder tiger by 4 Align guide. This modification clean this type of vibration ( but usually this vibration is at Higgh frequency)in my case the noise fresuency is low level.
I have inspected the tail grip blade assembly, and I detect I have wrongly placed the thrust bearing the conic face was in the wrong way.
But I'm not sure this is the reason of the vibration noise.

Regards,
Xavier

[crashburn]

Hi all,
I have done some tests this afternoon as I said at my previous post. The result is the following:
The noise is still present but I know now the noise is present with the rudder active at the left position and if I reduce the engine speed the noise disappeared.
Therefore I think the noise I hear is linked to the rudder rod vibration.
But mainly the part located between the servo and the rod guide mounted block.
I will try to limited the play between the plastic and the rod, and do new test.
I’ll keep you inform of the result as soon as I have news.
regards ,
Xavier

[crashburn]

Attached the link of a video from Christian who has the issue about the noise that I have.
Bu I don't have this tape of AC vibratio. Or this not visible only with my eyes.
[ame]http://www.youtube.com/watch?v=rejtmy_7fFE[/ame]
If some one has an idea he is wellcome.
Regards,
Xavier

[Danorn]

I have the torque tube as well, and I have the same noise at certain rpms. I changed tail blades, main blades, added 3 more tail rod guides. I also have a very fine vibration somewhere on the heli I cant find that caused the tailrod to snap in flight. Its also causing my main tank to foam bad enough to cause air to the header tank. I don't know if that noise is coming from the vibration, but I am not flying until I find it. I will post if I find it.