New V-Bar User - Elevator wobble G380

[aero_nz]

Hi All, new Vbar user here!

I have a Goblin 380 that was flying nicely on an AR7200bx (i.e. mechanically I believe it is sound), I pulled that FBL off to use on my Oxy3 and picked up a band new Vbar neo express to try something new.

I have paired this with two dsmx sats and a DX9, and the setup went smoothly (I really enjoyed the mac based setup via usb).

Initially I had a tail issue which setting up a transmitter gain of 40 quickly fixed.

However the Heli has a bad forward/aft wobble in hover (less prevalent in forward flight).

I first tried lowering the head gain to as low as 30 but this made it worse, increasing the gain by 10 per time it took until a head gain of 90 until the wobble was almost gone, but now it shakes during some hard turns.

Any ideas what this could be?

Note it is only forward/backward oscillation, nothing side to side.

Feel is medium 80, Agility 80-90, tail gain 65.

I did mange to get a bit of forward flight in - and oh that V-bar feel is nice!

[GregCA]

What's your head speed? Elevator nodding like that can occur at low head speed if the dampeners are too stiff. Try increasing the head speed to see if it goes away.

[aero_nz]

Originally Posted by GregCA

What's your head speed? Elevator nodding like that can occur at low head speed if the dampeners are too stiff. Try increasing the head speed to see if it goes away.

Hmm, thanks mate this has me thinking!

I am running a HW100v3 ESC using the internal HW Gov.

One of the things I wasn't used to in the setup is the throttle out and I set this to 75 and 85 for two banks on the Vbar.

But if I have flight mode on my transmitter set at 80% and then the throttle out on the Vbar app set at 85% does that mean I'm only getting 80%x85%
~ 68% at the esc.

That would be a significantly lower headspeed....
I'll need to tacho it next time!

[shadco]

.


Just set your speedy for heli gov off.

Set the end points using the vbc, then setup the vbar gov, easy as pie, bonus is autorotation is now setup automatically.

This has to be the easiest gov setup I've done.


.

[Laughingstill]

Is the bobble after a move or always?

[aero_nz]

OK I got my head speed to 3200-3600 on a G380 i.e. a reasonable range and set the cyclic gain back to 60.

The wobble is still there in a hover, and adding gain (even 70 or 80) doesn't fix it.

In forward flight it goes away, and it flies nicely - just can't hover?

Thanks in advance for any help.

[alyon187]

Theres other cases of this happening in the g380 forum if you look through it. I believe some of the issues they were looking at was a combination of the pyro motor and esc combination, too tight/loose of blades, tail belt not tight enough. Do you have or can you check these?