Hi all. I think I found a bug in 3.2.1 firmware. Yesterday when I flied with not strong wind my octa (18” props, over 10 kg of weight) tilted made roll with 70 angle, with ANGLE_MAX = 3000. In logfile DesRoll on this moment equals 30 angles. A bit more and copter could turn over. I flied a lot of times before with this setup and everything was good. I think it is a kind of uncommon bug, which probably moved to later version (3.3 etc). Log analyze did not geve any answers for such behavior, except many GPS errors. I understood that when GPS is not stable copter can suddenly change position, but it should not roll more that angle set in ANGLE_MAX parameter. Log file in attached.

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Hi friends

I think I have the same issue. I fly also a X8 multicopter. The model is a little bit smaller (16" props and 8kg weight). I noticed the problem the first time last autumn. It was a wonder that multicopter didn't crash... 

I fly yesterday on a film set. It was partially very turbulent. So I saw a few times that the copter overshoots on the pitch axis. For me there are two scenarios. One of them is a software bug, the second is a aerodynamic problem in the coax setup.

I hope somebody of the developers make a statement on this

Thanks a lot 

Michael

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May be its some kind of PID misconfiguration?

I would normally say it must me a PID problem. But I have the same issue on a smaller X8 platform as well. The thing is, that both multicopter fly very well, but sometimes they massively overshoots. So I don't know exactly where I have to tune.

I only have this behavior on X8 multicopters... for me it's strange...

I did some further tests. It seems that the PID values were not optimal for the X8 setup. I decreased the P values and increased I and D. My smaller X8 fly with this modification very well. I can't see any overshoot in the logfile. My bigger camera X8 still overshoots a little bit. I think it comes from the relatively heavy camera who can wobble a little bit due to the damper system. I hope I find a way to eliminate this issue.

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