Peco

Hi all,

I wonder if someone would be able to help me with this issue I am having.

When I lift my heli off the ground it is steady but whilst mainting the hover the tail starts to wobble up and down (so the nose dips and the tail raises then the oposite happens (nose rises and tail dips)
Last night it started doing that and then it behaved erratically. It kind of wobbled around as a spoon would when stirring a cup of tea / coffee, etc. It remained pointing the same direction but the whole heli wobbles.

I fly a Blade 400 with a sonix head and tail.
I replaced the belt and the tail boom and have rechecked and tightened all the screws in the head.
The baldes are new and a new balanced pair (tracking is fine)
I have upgraded the motor and ESC.

One opinion was that it could be an issue with the centre of gravity ?
Does anyone know how I would check this and does any one agree with this or can they offer any other suggestions ?

Thanks in advance for any support
Peco

TakeshiSkunk

Are you using training gear? I've heard it can cause vibrations in some cases, something about harmonic resonance (i think) can start some really intense vibrations that could be really dangerous. I think it has to do with the size and rigidity of the gear, like it won't just do it if it's too big or too small, but if it's close to a specific size/mass/something or other relative to the whole heli. I'm sure someone else can explain this better than me.

I'd say it could be the radio glitching but I'd think you'd be able to notice that on the ground. Maybe something is loose?

dooleyje

Your head speed is not high enough. The radio is fine. Go to your throttle curve and give yourself more power and the noding/wobble will go away

Jim

Peco

Thanks for the replies. TakeshiSkunk - Im not using training gear.

dooleyje - I have actually went from a 10 tooth pinion to a 12 tooth pinion when I was given an upgraded motor and ESC.

The whole head speed thing is a bit confusing and I really should read up on it.

Angel_W

Hi Peco:
Haver you check the paddels are even and the main shaft is not bend?

Peco

Angel_W - Yes paddles are level and bar is straight. Main shaft is straight

I'm gonna join a local club and see if I can get some help setting theremote up cos I am confused about the expo setting i should be usingtoo. It was set up for me with

Ch1 +85% expo
Ch2 +85% expo
Ch4  -20% expo

but i dont know what affect changing these would have ?

Its a Futuba T6EXHP
I changed the throttle curve to0-45-75-95-100 ? (but i dont really know what this does and ot still kinda wobbled