Weird 450x Tail Vibration/Oscillation

[tutelarRC]

I have posted two videos showing a weird oscillation of the tail. Not sure what is causing it, but the servo jitters back and forth while it is happening. It may be the servo causing it, or the gyro/servo trying to prevent it.

Is there a servo delay that can or should be set, similar to a GY401?

Short video of heli in flight (you can hear the jitter):
[ame]http://www.youtube.com/watch?v=JMibVMoUBuA[/ame]

Short video of heli with head removed. Not touching the controls, simply moving the tail:
[ame]http://www.youtube.com/watch?v=c1MvSx0E7PM[/ame]

BTW: A little disappointed that the main blades needed 1g of weight to balance them. Two thumbs up for HobbyHobby who replaced them with new ones. New ones were perfectly balanced.

[ShaneJourdan]

Yeah the blade thing seems like it maybe an epidemic.

My friend that seems like a bad servo without much doubt...

[ShaneJourdan]

You are set to 1520p on the beast right, did you change any settings?

What gains are you running?

[tutelarRC]

No settings were changed on the receiver.
Dial 3 is in the middle.
Transmitter gyro setting is 54%.

(Blades were same weight but CG was way off. Needed 0.5g on opposite ends of the 2 blades to balance. Really bad vibration during spool up. Balanced blades and the heli spins up like a dream.)

[ShaneJourdan]

I would call HH and ask for a replacment. Its bad

[tutelarRC]

That call will be made today. Will post results. Thanks!

[azezeil]

Mines doing this exact same thing. I set it up as the manual said and during high speed reverse flight or any high collective maneuvers it'll vibrate just like that. Did you find out if it was a bad servo or something else? Wondering if I should call HH too.

[TheHeliDude]

I get the tail vibration in fast reverse flight too. Interesting to see your video of it with the head removed. This was happening for me with all dials in the middle (stock) and was happening before my first crash. Although Im repairing from my first crash today so I'll check the tail on mine with the head off also

[Pilot in MO]

One thing you might want to check (if you haven't already) is the tail servo geometry, by that I mean is it still running straight to the pitch slider? If it is bowed slightly, the servo will quiver and the tail gyro might be amplifying it as it tries to compensate. I would watch the servo wheel before it begins to oscillate to see what it is doing.

It is very possible the servo was damaged in the crash, I think a rebuild kit for the servos are less than $3.00.

Good luck

Edit: I may have misread about crash damage, you didn't mention a crash but another poster did, guess I got confused

[tutelar-rc]

HH sending a new tail servo. Will post results when it arrives.

[azezeil]

I sent HH an email and they're sending me a new tail servo also.

[tutelarRC]

Bad news. New servo did not fix the problem.
HH is going to talk to the Blade guys to get some advice.

[NickySantoro13]

had the same type of problem with my 450x... did all the basic play/tweaking to the gyro gain ect... finally went an bought aluminum tail servo mounts and the spektrum h5020g tail servo.

once installed and setup in the ar7200bx the tail wag was finally gone.

hope this helps

also do not use plastic tail servo mounts with h5020g servo (too big of a servo for the plastic mounts)

in first pic im just letting you see size difference in two servos (ds76t is left one spektrum is of course on the right)

[azezeil]

Anyone have any new info on this? The servo HH sent me just came in tonight and I can't test it until the weekend. I also have a h5020g in case it doesn't fix it, but don't have the aluminum tail mounts for it yet.

[meatwad99si]

Did you have any problems before this started? check out my threads

https://www.helifreak.com/showthread...13#post3820213

i have a few interconnected threads so start at that one, I had no rudder control one day after initializing, redid battery connection and it worked but i all of a sudden had this issue. I was able to lower my gain from 77 to 67 and it has stayed away. But im not doing anything to hardcore. just some fast banked turns and on fast right handers my tail was freaking out but now its not with the gain lowered. I wonder if I was doing some hard reverse flight if it would still freak out. You think I should install that spek tail servo?

[M3bluegsr]

Check your one way bearing, I had a tail problem and replaced servo, did mech setup a million times..turns out it wasnt autorotating. The bearing sleeve and owb were damaged and clicked before it finally locked together.

[azezeil]

Well, gave it another test fly with the new servo and nothing has changed, still getting the massive vibrations from the tail under heavy pitch changes and fast reverse/sideways flying. Messed with the gyro gains and it changed nothing. Checked my gears and they're fine. I'm thinking it's just a bad micro beast unit. At this point I'd rather them just send me a replacement bird as I specifically got the 450x so I wouldn't have to do all this fiddling around and It'd be ready to go out of the box.

[meatwad99si]

good luck with that, they pretty much told me send it in cause my 4 batterys are bad or i didnt set it up correctly...

[tamupino]

Any news on a resolution to this problem? Im having the exact same problem that I didn't attribute to tail wag until reading this thread. I've never seen a tail oscillate so quickly before now.

I was going to call HH and request a replacement servo but that hasn't seemed to work for you guys.

[TDMModels]

Have you checked the alignment of the servo push rod to the tail rotor. If it is out of alignment just a little bit, the tail will wag.