It's interesting that you have a similar effect with different units and helicopters. That makes me confident, that there is a way to fix it by adjusting parameters or maybe something in the firmware(?).

I agree with you that it has to do with speed and radius of the loop – that's my experience too.

Were are are the differences between your settings and ours? This way we can perhaps exclude some parameters.

I've attached the Goblin's settings to this post for reference. I did have a list I scribbled down, but can't find that right now - I also want to grab the settings off the Pro (Trex), and will upload them along with a list of differences that I have noted, once I get the chance.

Yesterday I tried to figure out which influence the center of gravity has on the effect:

Shifting it to the front improved the feeling a bit, so that the tilt angle became less.
I hope that gives another hint to find a solution...

Hi @all!

I recently purchased a Spirit RS Unit and mounted it on my Logo 500SE for testing.
From the start the helicopter behaved somehow funny when it came to nick/elevator inputs.
(Wobbling after harsh inputs while hovering, pitching up on low head speeds, etc)

However, I was able to get rid of almost all these things by playing around with the parameters.

Now, I still have the same problem described in this thread.
If I enter a stall turn manouver with high speed, high pitch and a fast elevator input, and then set the elevator input to zero, the helicopter bounces forward a few degrees.

I have tried setting the flight style, the cyclic gain, the cyclic feed forward, cyclic rotation speed and the cyclic ring to low and high values.
Nothing changed this behaviour so far.

Is there a solution to this problem?

Hi Tomáš,

have you any news about this problem for us?

Bjoern

Hi,

I am afraid, but we are unable to replicate the issue on our helicopters or with our pilots.

What could play a role is increasing Cyclic Ring value - Aileron/Elevator Range. Because if range is too low, issues with elevator could arise. Especially in a higher speed or wind it could loose original attitude due to low range.

_________________
Spirit System developer

Hello,
ok, if others can do it, it must have something to do with the attitudes.
I can still reproduce the problem on every flight.
I checked the settings again, everything exactly 0 ° pitch and the 6 ° are set exactly.
Maximum pitch is + -12 °.
Here are my current settings.
I am happy to test the settings, the main thing is that my helicopter no longer has its own life and flies like with a NEO
What exactly should I adjust now?

Hello,

after looking at the settings I think the problem might be happened due to very high Cyclic Feed Forward and at the same time very low Rotation Speed.
In fact, if you will set CFF that high it could have negative impact on rotation speed parameter, because you are trying to make model very fast while rotation speed is trying to make it slow but in other way.
So it is like trying to drive fast, so you will use full throttle but because it is too fast, you have handbrake all the time.

I recommend to try more usual settings first. Set Cyclic Feed Forward to 6, while Rotation Speed to 10-12.
And to make smooth feeling around center which is good for F3C I recommend to increase Flight Style to 8.

Also it could be helpful to set Stick Deadband to a higher value, for example 5 to make sure that stick centering is not playing a role.

_________________
Spirit System developer

So, now I've tested it. Unfortunately, the effect is more or less there.
Again to explain: If you fly into the candle gently, everything is ok.
It can be reproduced if you fly into the candle with a small radius and high speed.
The helicopter then wants to go forward in the upward passage. You have to come to terms with this with a positive pitch. At the moment when you control the pitch, the helicopter takes its nose down.
Since I'm flying mode 3, I exclude a steering of elevator.
I just set the parameters up and down and tested them (each time I adjusted it and started over). The behavior remains more or less. It is not possible to get away.
Another idea?

After many months of not being able to look into this, I've come back to it.

I have changed things mechanically on the Trex 700 (move to the F3C specific parts etc.) - but the Goblin remains mechanically the same; the setup on both models is now slightly different too (now running a 0 degrees pitch centre for flying/aerobatics, rather than my old-school pitch range which gave zero lower down on the stick - but still linear between min/max), and ensured the units are both setup correctly from the ground up (they both were, but checking seemed prudent), and running the latest firmware.

So far, and it's only been 4 or so flights, both models *seem* to be behaving better. I shall, when weather allows, put them through their paces and update. I am also playing with the various settings via banks, so I switch on the fly and do back-to-back comparisons. If I come up with anything useful, I report back...