Tail wobble on new 120S

[02_919]

Hi
I've been working with Horizon on my dad's new 120S he got last month. Since its first flight the tail has wobbled around when flying. You can hear the motor changing pitch with the wobble which makes it sound like a very out of balance tail rotor.
Horizon has replaced both main rotors and the tail rotor but neither has helped. We picked up a set of the heavy duty orings from JonJet and that helped some but it still isn't solid.
I can't post a vid now but FliteTest reviewed it on their YouTube channel a few weeks back and theirs does the same thing.
Does anyone have thoughts on what else we could try before sending back to Horizon? I'd like to know if other folks have had a similar experience or if we just got a lemon.

FliteTest vid is here.

Fixed and Collective Pitch Helicopters | Flite Test (12 min 12 sec)

[steckrinski]

This wobble was extreme at powerchanges.
Took mine back to the shop, after demonstration, they exchanged the heli.
However, this time I made a checkflite with the new one, the wobble was no longer apparent.

[jrman83]

With battery and canopy in place, have you checked CoG? It may not like where you are placing the battery and may change if better balanced. If you open up the blades fully and put one finger under each blade right where the bolt for the blades go into the grip and lift you should be able to see how flat it sits. If off, try moving the battery around to see if you can make better.

[BrokeDad]

Mine has the slight wobble too. I think it's in the design. I just use it for relaxed level flights. Glad I only paid $90 new for it.

[02_919]

We finally sent ours back to HH after several rounds of replacement parts that didn't fix. I agree it is probably a design bug

[BrokeDad]

I just decided to try something and it is actually getting rid of the wobble. I went into gyro on my DX6 and set 15% on Pos 0. Chan is Gear, Switch is Rud Stick. I'm still playing around with the percentage but it seems to make a difference. If I put it back to 0 the wobble returns.

I've also got it set up as a Heli instead of Airplane which the manual calls for . Time for some more test flights when my batteries charge again. I only have 3 for it.

Update: I set it to 50% and now the tail is dead steady. To be truthful I'm still learning and don't exactly know all this setting does.

[SCflyer]

I know I have seen this mentioned in other threads and it actually made a difference for my 120S. The main blades need to be fairly tight with this heli. When I snugged down the blade grips according to the instructions in the manual my tail wobble pretty much went away. I was getting a noticeable wobble when I flew the bird as it came out of the box. The rotor blades would flop around fairly loosely at first.