Hello,

first of all I want to introduce myself. My Name is Frieder, I live in Germany and I fly F3C in competitions.
I have been using Vbar-Neo for years, but I don‘t like to be more and more dependent on the V-bar control so I changed to Spirit 2. (I am using Jeti)

Anyway, now I try to figure out how to set up the Spirit to be suitable for the calm and precise F3C-style. For hovering as well as for aerobatics. My helicopter is the XLPower Wraith-E 760 F3C

I struggle a bit with maneuvers that include flips (like the the DOUBLE CANDLE or the UX). The problem is, that after the flip when I already put the stick back to center, the helicopter still flips on for a few degrees.
I figured out that higher cyclic feed forward and lower cyclic gain reduce that behavior but it is still there…

My current values are:
Cyclic Gain: 40%
Rotation Rate: 10
Cyclic feed forward: 10
Flight Style:6

Can I still decrease the cyclic gain or is that dangerous? Are there any other options to get rid of that behavior?

I would be happy if you have some suggested solutions and maybe if you could share your experience on hovering-parameters as well!

Frieder

Hello,

changing Flight Style can help you a lot. Please try to change to 8.
Normally there shouldnt be any movement as soon as you will release the stick with any configuration.
Maybe you can write what is your Geometry 6° value?

Isnt the behavior rather an elevator bounce back? Elevator Filter can be well related to the issue. What is your current value?

_________________
Spirit System developer

Thank you for the answer!

My 6° value is 119

You are right, I had a "bounceback" after fast/aggressive stick inputs.
The behaviour I described above occurs after slower inputs.

Last flight I changed the parameters you suggested:
Changing the Elevator Filter from 2 to 4 improved the Flips a Lot. The bouceback is almost gone.
I could not notice a signifikant effect of Flight Style 8 in the Flips.

The behaviour I mentioned in my first post ist reduced as well, but still there.
To specify what I mean: I flip the Heli forward or backward and suddenly move the stick back to the center but the heli continues rotating in the same direction as the flip for a short moment.

Hello,
a few days and a few flights later I unfortunately still have problems to achieve a acceptable behavior for F3C.

Let me try to to explain my problem using the "(Double) candle with descending flip" as an example:

I splitted the manoeuvre into two parts in which two different issues occurred.
Please find two drawings and my settings attached.

Part 1:
(1) – Helicopter flies straight and pulls into a vertical ascend performing a quarter of a loop.
(2) – At the end of the quarter-loop (when the helicopter is vertical) I instantly stop pulling elevator.
(3) – From now on the heli tilts forward smoothly to an angle of about 15°.
(4) – As a consequence I need to adjust the position that it is exactly vertical again. That is a problem because for the judges it's a mistake and the manoeuvre will be downgraded.



What I did: I played around with cyclic feed forward and flight style to reduce that behavior. With the attached settings I achieved the best result. But I was not able to get totally rid of it.

Part 2:
(1) – After my adjustment and a nose up stop the helicopter starts falling backwards vertically for 2m.
(2) – The heli performs a half pulled travelling flip.
(3) – When I stop the heli after the flip it flips too far and instantly bounces back to the intended vertical nose down position. That bouncing should not be either.
(4) – Afterward the heli pulls again into a straight horizontal flight.



What I did: I increased the elevator filter to 4, what improved the flip-behavior but it could not eliminate the bounce.

Thank you in advance for your help!

Frieder

I have tested today my spirit DS with the figures from Frieder.

I must say, that I have the same problems.
For e.g. with the candle.
After I pulled the helicopter fast in a vertical ascend I stop the elevator. After this my helicopter tills about 15° without any stick input.

After this I have tested a second helicopter with a NEO and there are no such effects.

It would be nice when you can give us some hints to solve this issue.

Björn

Hello,

the problem you are describing is likely due to geometry correction which is active all the time and is learning from how the model flies.
I guess the problem happen because you are moving with the collective pitch which plays important role in this correction. This helps to eliminate several unwanted phenomenons that are common for FBL units.

Could you try to not move with the pitch too?

You could resolve the problem by decreasing Geometry 6° value which will make all corrections less apparent.

Or we can send you special firmware where these corrections are turned off.

_________________
Spirit System developer

Hello,

so for my understanding... The 6° geometry value only works for automatic corrections. So the full control will be available and only the automatic corrections will be decreased. Is this right?

So if we have for e.g. a version without this 6° value (or zero), we must correct the flight line of the helicopter self.
Or have we some additional effects?

Thank you very much for your hints and the offer to provide a firmware!
I can confirm, that the phenomenon depends on the amount of used pitch. Unfortunately it is unavoidable to use a lot of pitch when there is much wind.

I will try to decrease the 6° value this weekend. Do you have a suggestion in which steps we should proceed? How far can we go and what do we have to expect?

Frieder

Hi,

I am now writing directly from the field. For your information, Björn and I know each other and we met today to set up our Helis for F3C…

Now both of us did some flights playing around with the 6° value. We agreed, that lower than the „normal“ values make it worse (we decreased by 20-30). So we tried higher values, which resulted into the same tilt-angle but it tilted back for some degrees by itself.

However, we are both still not happy, and a bit at a loss. What else could we try?

Now we are trying to make a video from our problem. Later we will post a link…
Maybe then it becomes more clear and easier to fix.

Frieder

Hi,

Here you can found the videos:

https://youtu.be/Fd4UsFdEGxc

And

https://youtu.be/bwzuAw4G220

Björn