VTOL unstable takeoff after manually restoring outdated params

ArduPlane VTOL Plane
1

I’m having trouble stabilizing my VTOL during takeoff in Qstabilize mode. I recently upgraded from Cube Black with AP 3.9.11 to Cuav x7 with AP 4.5.4, restoring old parameters from the previous setup. After a few seconds in the air, the aircraft pitches up uncontrollably. Can anyone help diagnose the issue? I’ve attached the log file for reference.

Thanks,
Odnan

2

Hello @Odnan , welcome to the community,

When updating the firmware version the parameters are automatically updated, and must NOT be restored manually. Restoring them manually causes the problems you are experiencing.
Do not do that.

Update to 4.2.x and after that update to 4.5.4.

Do not mess the parameters up.

3

Hi @amilcarlucas, thanks for your reply. I’ve updated the PIDs using the ArduPilot Plane 4.1.x PID Calculator after restoring the old parameters. Is this not sufficient to make the old parameters compatible with the new setup?

4

Probably not, there have been many many changes since 4.1

5

Understood. Would you recommend installing firmware 4.1 or 4.2, importing the old parameters from 3.9.11, and then updating to 4.5.4? I’m hoping to minimize the amount of tuning required.

6

No, install 3.9.11 and load the backup parameters.

Then update to 4.2.3

After that update to 4.5.4

1 Like
7

The problem is that there is no 3.9.11 firmware available for the Cuav X7

8

Install 3.9.11 on cubeblack.
Restore the parameters

Update to 4.2.4

Save the parameters

Install 4.2.4 on cuav

Restore the saved cubeblack parameters from 4.2.4

Update cuav to 4.5.4

9

Thank you @amilcarlucas. I will attempt to install firmware 3.9.11 on Cubeblack, then use that as a base to update the Cuav as you suggested.