Goblin RAW 700 Gasser - wobble during auto

[Scott H]

I have a new goblin RAW 700 gasser and overall it flies great on the GTR. During an auto as the heli descends and RPMs reduce I'm getting a wobble of the heli. It's not specific to the elevator, though arguably it's hard to tell.

Some settings:
6 degrees is 118
CFF is 3
The elevator filter is 3
Cyclic gain is 64

Dampers are what came with the model.

Any suggestions would be appreciated.

Scott

[Scott H]

Today, I increased the Elevator filter to 4 - made no difference to the low speed wobble
I lowered the sensor from 63 to 60 to 50 to 40 and none of these changes made a difference to the wobble.

Is there anything else I should try?

[vvv850]

Maybe it's just the limit of the airfoil? I'm not sure if this can be tuned out using the FBL.

[HeliMLM]

some kind of wobble is not unusual on brand new helis on the first flights - especially using low/lower rpms (so this is for sure the case in autos). most of the time it's just the time the dampers need to fully settle - at least if they are greased correctly. i do not know your heli at all - but it's a common topic on the first flights of any new heli and could disappear by itself. if not - be sure the dampers are greased correctly...

[ZeXx86]

For autorotation there should be no need to change any settings of the unit normally.
There are much lower RPM which mean for the best stabilisation it will need even higher gains. So if you do not change gain it can't cause oscillations due to too high gain.
I am afraid there is no parameter that could fix the wobble when motor is turned off. If there is a wobble then it is only matter of rotor head stiffness.
For example with DFC type rotorhead wobble is usually much more noticeable at low RPM just because it is all more rigid.
Using a lubricant for dampeners can help.

[franz88]

the helicopters in certain phases they have resonances.
it is very evident when you turn on the helicopter and gradually the rotor starts.
later when it takes more rpm disappears alone.
to some models during this phase the crown dance all, other models they may have vibrations, each model has its own problem.
I think turn it off and when the rotor reaches certain revolutions that defect happens to you.
I think it's just mechanical because others do autorotation too.
Try changing the rpm rotor maybe doing so when you turn off the engine you are no longer in that phase

[Scott H]

I tried software setting changes, but in the end, put them all back to how I like to fly. Instead, I replaced the stock rubber dampeners with XGuard versions. That wasn't an immediate fix either. I then reset the main head block to the main shaft. After removing the main and tail blades, I loosened up all three bolts, spun up the motor and allow the block to find its center and tighten the side bolts a bit, and repeat spool up and centering until the two side bolts were tight, then tightened up the jesus bolt.

If there is any more wobble during an auto, it's minimal and it doesn't bother me. Given the wobble lessened, if not totally disappeared, after resetting the main block, I'd say that was likely the issue and not the dampeners, but I'll never know.

Either way, it's flying great now. Spirit is a champ and with the XGuard rpm sensor, there are no issues with the governor either.