Intermitent violent tail shake

[paul 5ive-t]

just maiden'd my new build goblin 700 comp with msh brain unit, I have not touched advance settings yet, am running hardcore in all modes with 2200 headspeed, it fly's spot on apart from every now and then when pushing it I get a violent tail wag until I say turn it and lower pitch, then it spot on again, tail gain is still at the recommended 45% in the software.

[tomatwalden]

Lower your tail gain. Recommended values are just starting points, as many factors will affect the actual right value for a given heli - eg. type and size of tail blades, tail servo, horn length, head speed, etc. etc.

[Grumpy]

+1... you need to lower tail gain by a few point. The recommended settings are just a guide they need to be fine tuned for each heli.

[paul 5ive-t]

cheers guys will give it a go, just confused me a little as no tail wag and it says to raise gain until wag then back off.

[tomatwalden]

yeah - no wag in flight - not just in a hover ... If it's wagging during manoeuvres, it needs to back down a bit.

[paul 5ive-t]

awesome....will give it a whirl tomorrow, its my first proper build so still a lot to learn, cheers.

[paul 5ive-t]

cheers guys, tail problem on goblin sorted now thanks, one other thing is on the three modes you can have there is cyclic gain and agility, the cyclic gain started off at 43% and it says raise 2 or3% at a time until head shakes then back off till stops which is fine but I am at the max 60% and still no head shake! has anyone and idea's on that one?

[waveydavey]

The gain will be affected by other things on the heli, you can normally induce oscillations by giving quick stabs of cyclic especially aileron. But if I were you I'd fly it, does it feel locked in, does it feel solid, if you put cyclic in does it settle straight away, if yes then I would say that the gain is good to go. Only change it if it doesn't feel right. In fairness you don't want a headshake as it's sometimes quite violent.

[tomatwalden]

cheers guys, tail problem on goblin sorted now thanks, one other thing is on the three modes you can have there is cyclic gain and agility, the cyclic gain started off at 43% and it says raise 2 or3% at a time until head shakes then back off till stops which is fine but I am at the max 60% and still no head shake! has anyone and idea's on that one?

By "head shake" do you mean a kind of vertical nodding movement? - usually more noticable as a tail nodding?

If so, it's typically seen on Goblins with low head speed. Try a higher head speed.

Example : https://youtu.be/_T95IfJZ-Rk?t=1m24s

[waveydavey]

I don't think he's got any wobble at all Tom, he's looking for one in order to understand where he's at with the gain level.

[paul 5ive-t]

cheers guys, I am running a 24t pinion with 60 70 80 flat line throttle for the kosmik, headspeeds at 70 approx 2000 and 2300 at 80 heli fly's well even when doing fairly aggressive moves and stays on track, I got no head shake or wag at all and as I say I ran out of gain in the mode section for the cyclic, the only problem I have left to sort is on a quick half a pitch pump up it drifts slightly to the right?

[tomatwalden]

I don't think he's got any wobble at all Tom, he's looking for one in order to understand where he's at with the gain level.

ah. I misread the post.