Spirit System

"You can always share your settings"

That's oke, what settings you need to know?

"In any case 800 class helicopter might need Pitchup Comp at 3 - 4"

Why would it suddenly need 3-4? I have always had it set to 1 and never had a problem. Earlier you said yourself: "Pitchup Compensation can be left at 1"

"Also there are another things to check - whether servos are at the center (servo arms and ° between main blades) when clicking at the Subtrim (tuning)"

Im not sure why you mention this? If this would not be setup properly than i would also have the issue with previous firmware.
But i can assure you that everything is at center 100%, swashplate leveled and 0 pitch in blades at center. Always has been perfect!

Since you performed major update almost all algorithms are working differently. They were designed to fix issues that previous firmwares had. Since it is different, it is basically as a very different FBL.
If you have problem with changing values, you can always downgrade to a previous version.

Note, I am not asking about checking it with stick pitch in the middle, but to check exactly at the Subtrim (tuning) menu.
Please share 4ds settings file. This contains all your settings.

If you need explanation why, it is always described at the ChangeLog for each version.
It is very recommended to read.

Not only mentioned parameters here might require changing. See ChangeLog for 4.0.0 and 4.0.1.

Good morning,

here is my 4ds file.
Today i will set Pitchup compensation at 3 and test it. Hopefully it helps.

"Note, I am not asking about checking it with stick pitch in the middle, but to check exactly at the Subtrim (tuning) menu."

Yes i understand what you mean and like i said the setup is absolutely perfect!

Just tested with pitchup compensation set to 3. Still the same.
Fly forward, give it some collective to pick up some speed, heli slowly tilts backwards and up she goes.

You could try more integral and set the integral damping to zero.

Damping has changed in 4.0.1. I would give it a try.

With each new version/update, minor adjustments to the setup may be necessary.

Nazar wrote: Sun 28. Sep 2025 20:17:21 Today i updated to 4.0.1.
My heli TREX800 flies great except for 1 thing.
In fast forward flight the helicopter automatically levels itself horizontally and of course after that it starts gaining altitude because of the pitch.
It has never been like that before. The nose would always stay down by itself but now i have to adjust it constantly otherwise the heli levels itself.

Why is this? Anybody else experiencing this also?

Hi
With the default settings in version 4.0.1, my helicopter had the same behavior as you. I changed the sensor type to low latency, set the pitchup compensation to 5, and set the elevator filter to 4.5. The tail drop disappeared, and I was also able to significantly increase the cyclic gain, around 85%.

Hello Tomas,
if mostly all parameters are behaveing in an other way then before, then would it be not better to make a presetting of all helicopter sizes, like 450 Class, 500 Class, 600 Class and 700 Class - All parameters would be related to the corresponding heli Class -

I am aware that the settings vary from helicopter to helicopter in the same classes...
These are then maybe not the best settings but an secure and good one for the first flight and thats the most important -

Then it would be also absolutely necessary to explain all single parameter and their mode of action - please do not refer to other documents that makes no sence to me - It is better to do that on one new document so you don't lose track, this will help all users -

I have to say that I am also not so happy because the bahavior is different and I am not shure what to change in the settings -
So I think it would be necessary to to explain it in detail -

Best regards
Matthias

Hello Matthias,

thanks for your proposal. I see it the same way.
An explanation of all single parameters and their mode of action would be really very helpful for the users, especially for those who are not yet very familiar with the Spirit setup (like me).
I am convinced that Tomas understands us.

Regards
Hermann

Hello,

it seems there is problem with Elevator Filter not working properly in all cases. So it has nothing to do with settings. In two days we will release new update.

stesax wrote: Sat 04. Oct 2025 20:31:29

Nazar wrote: Sun 28. Sep 2025 20:17:21 Today i updated to 4.0.1.
My heli TREX800 flies great except for 1 thing.
In fast forward flight the helicopter automatically levels itself horizontally and of course after that it starts gaining altitude because of the pitch.
It has never been like that before. The nose would always stay down by itself but now i have to adjust it constantly otherwise the heli levels itself.

Why is this? Anybody else experiencing this also?

Hi
With the default settings in version 4.0.1, my helicopter had the same behavior as you. I changed the sensor type to low latency, set the pitchup compensation to 5, and set the elevator filter to 4.5. The tail drop disappeared, and I was also able to significantly increase the cyclic gain, around 85%.

Thank you for your contribution.
When i got the time i will try out your suggested settings.

I have always had cyclic gain set to 60%
What benefits are there when set to 85%?