Copter motors twitchy, vibrating on takeoff after autotune

Hi. I am experiencing the second autotune that apparently went OK but after which the copter´s motors are twitchy and sound like continously cutting off at takeoff. The first autotune that I did two days ago left it like that, on the first takeoff after that the copter seemed so unstable at 25-30 % throttle that I was afraid to takeoff. Today I resetted the PIDs and did another autotune hoping that something was wrong in the first one. Same thing happened with the difference that today I decided to takeoff. Takeoff on poshold it is not possible at more than 50-60 percent throttle, it is like the copter got no power. Althold is the same. In stabilize mode I went over that vibrating moment and reached 40-45 percent, compensated the pitch a bit cause the shaking appears to take the copter backwards a bit and I was able to takeoff. Once in the air, switched to althold then poshold and copter flies perfectly, like immediately after the autotune. Even so I am a bit afraid to fly it like that. I would be grateful to hear any opinions or past experiences, or maybe an explanation on why this happens. I am flying with BLHELI ESCs and I recently changed the timing to medium high, this being a 680 pro hexacopter. Could the timings have something to do? Need to mention that if I reset the tuning params now to the default ones the motors work perfectly smooth but I do need the autotune on it. As soon as I do it I get to the actual shaky state.

If the throttle stick is in the middle (40% ~ 60%) the vehicle will maintain the current altitude.check this about althold throttle issue.
about the twitchy, I think It’s still your PID tuning issue can you post your tuning log?

Sure, here it is. Last 3 takeoffs are affected by the issue, first long flight is autotune process.

This seems like my case Weird results after saving AutoTune PIDs but then, if that discussion is right, seems that it is a firmware bug which I highly doubt, I am on 3.6.9, far from the version that discussion talks about. Will flash latest 3.6.10 anyway and see if anything changes. It is frustrating to see how well it flies before landing, with autotune switch high and how all that breaks after saving params and arming again :frowning:

What I am seeing at first glance is that stabilize roll P and stabilize pitch P are out of bound in both autotune I did.
First one is ATC_ANG_ROLL_P - 8.8 (range is 3-12) OK
ATC_ANG_PIT_P - 17.37 (range is 3-12) KO
Second is ATC_ANG_ROLL_P - 18 (range is 3-12) KO
ATC_ANG_PIT_P - 15.08 (range is 3-12) KO
So if anyone has any idea why these are so high after autotune I think I will find the issue.

Not sure if related mine flies o/kish in stab mode but horrible in loiter,pos hold aly etc after auto tuning

I do not think is related cause mine flies ok in loit and poshold if I takeoff in stab then switch mode. Is just that the 25-35 % zone of the throttle is shaky as hell. If I pass over that vibration goes off and it is apparently OK. As I said, I think I could fly it like that and disregard that vibration zone but what if something is chewing on my motors flying like that and I end-up destroying the drone or worse, lower it onto someone´s head cause I wasn´t patient enough to find an explanation :frowning:

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I haven’t see your log yet,But I have the same PID auto tune issue with the roll PID. After I set autotune aggr to 0.75, and re-tune it. problem solved, the wired thing is the PID wasn’t changed so much.but the twitch and the vibration was gone.

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It’s better to reflash the FC reset all your parameters, and tune only one axis at one time and test it