Problem with latest version 4.0.1

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stesax
Posts: 9
Joined: Sat 04. Oct 2025 20:24:20

Nazar wrote: Mon 06. Oct 2025 19:26:19
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%?
Hi,
I prefer using high gyro sensitivities.
You can try increasing the gains little by little, until your mechanics allow , without overdoing , and see if you find any benefit.
stesax
Posts: 9
Joined: Sat 04. Oct 2025 20:24:20

ZeXx86 wrote: Mon 06. Oct 2025 14:53:34 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.
Hi,
I can confirm.
While on the one hand you find the desired behavior, on the other hand you lose precision in elevator control, and precise altitudes become difficult to achieve.
It would be nice to be able to control the elevator's cyclic rotation speed independently of the aileron's cyclic rotation speed.
Only a few 3D helicopters can rotate at the same speed in both flip and roll; most helicopters, whether sport, scale, or F3C, can rotate faster with aileron, but slower with elevator. With separate controls for the cyclic rotation speed, we should achieve excellent elevator feel as well.
ZeXx86
Site Admin
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We are looking forward for anyone who could test the fix related to pitching up of the model in a fast forward flight before it is released oficially. Anyone interested can send me private message with serial number of their Spirit unit.
Spirit System developer
stesax
Posts: 9
Joined: Sat 04. Oct 2025 20:24:20

ZeXx86 wrote: Tue 07. Oct 2025 11:17:18 We are looking forward for anyone who could test the fix related to pitching up of the model in a fast forward flight before it is released oficially. Anyone interested can send me private message with serial number of their Spirit unit.
pm sent
stesax
Posts: 9
Joined: Sat 04. Oct 2025 20:24:20

ZeXx86 wrote: Tue 07. Oct 2025 11:17:18 We are looking forward for anyone who could test the fix related to pitching up of the model in a fast forward flight before it is released oficially. Anyone interested can send me private message with serial number of their Spirit unit.
Hi,
Today I tested the new version 4.02. The behavior complained about by user Nazar on my model is significant with pitch up compensation set to 1, slight if set to 3, and absent if set to 4 or higher, regardless of the value assigned to the elevator filter parameter. I reduced the elevator filter parameter to 0.8, from 4.5, increasing elevator feel without losing precision in the flight path or when exiting turn stalls and descents.
With these parameters, the model was already flying more than well.
Nazar
Posts: 12
Joined: Fri 15. Nov 2024 18:32:08

Hi,

what is the helicopter size you tested it with?
stesax
Posts: 9
Joined: Sat 04. Oct 2025 20:24:20

Nazar wrote: Tue 14. Oct 2025 9:36:58 Hi,

what is the helicopter size you tested it with?
Hi,
is a tron 7.0, 700 size whit rotor blade rotortech 720 F3C.
Nazar
Posts: 12
Joined: Fri 15. Nov 2024 18:32:08

That would probably mean i still have to set pitchup compensation to 5 with my TREX800.
Seems to me nothing has changed.
stesax
Posts: 9
Joined: Sat 04. Oct 2025 20:24:20

Nazar wrote: Wed 15. Oct 2025 10:33:27 That would probably mean i still have to set pitchup compensation to 5 with my TREX800.
Seems to me nothing has changed.
If you are using the 4.01, you need to increase the pitch up compensation to 5, set the elevator filter to 4.3 - 4.5, and set the cyclic feed forward to 1. Also lower the dual rates on the elevator control.
ZeXx86
Site Admin
Posts: 12831
Joined: Mon 29. Apr 2013 16:06:44
Contact:

Bigger helcopter mean that Pitchup Compensation should be set higher. So value 4 - 5 correspond to 800 class.
On the other hand we updated firmware and added several tweaks that might fix the issue even with your previous settings.
Spirit System developer
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