I’m hoping someone can give me some tuning insight. I been working on getting this airplane flight worthy for about 6 months. I have quite a few struggles ranging from servo jitters to bad FPV video that have really slowed the project down. I have all of the other issues worked out but it won’t fly right in any of the stabilized modes. It looses altitude in auto-tune and fbw-a with the pitch stick pulled all the way back. If I let Auto tune run, witch is nearly un-flyable, I end up with aileron flutter and roll oscillations.
I thought perhaps the pitch down tendency had something to do with the STAB_PITCH_DOWN parameter even though I am not flying at low throttle. I disabled it but it made no difference. I have also tried adjusting the AHRS Trim Pitch a up a bit but that doesn’t seem to help. I have also tried cutting down the roll P value to .3 but it still oscillates.
I feel like the plane is so far from a correct tune that I don’t know where to start. It does fly pretty well in manual mode aside from needing about 1/6th to 1/8 pitch stick to keep the nose up.
This is a video of the first flight in the data flash log. It is primarily flown in manual mode. You can see that I flip it into FBW-A mode a few times (3:10) but immediately take it back out,.