Trim plane in manual. What happens exactly?

[newaysfactory (Adriano)]

Hi,
I know that with ardupilot, I don’t have to touch the trims on my radio, otherwise I would get in trouble. But I want to understand exactly what exactly the issue is.

I guess that changing the radio trim will:

• work as expected in MANUAL mode. Except, I think, I would have some authority cut at the boundaries
• Give issues in FBWx mode since stick inputs are no more servo positions but pitch/roll references to follow, so the plane will not go straight.

Is this right?

I already read a couple of other discussions without having cleared my doubt:

It is possible/useful to trim the model in manual mode with the radio control

In this case it made a quite significant difference [image] Dashed lines are the result of autotrim’s work. Green is right aileron (up is up) Red is left aileron (down is up). In this case there is quite a lot of difference between left and right aileron. IMHO trim should be handled before the servo mixer not inside.

SERVO_AUTO_TRIM and Manual Flight Mode

I haven’t tested this limit, but my trim knob settings were no more than three or five clicks. If it’s more than five clicks, I fix the problem mechanically by changing the length of the rods

[LupusTheCanine]

Mostly correct though the issue will happen in all modes with pilot input enabled including AUTO and RTL.