I fly a QAV400 with Pixhawk and 980kv motors. I had done several AutoTunes in the past with this setup without any problems.
Now I upgraded the motors to 1100kv ones and now it happend.
Used the same PID as for the kv980 and set the copter to autotune.
SimonK NFET 20A with newest Firmware 2014-03-06 (https://viacopter.eu/multirotor-shop/escs-speedcontrollers/20a-nfet-esc-with-simonk-fw-multicopter-store)
Tiger MT2216-9 1100kv motors
The first crash happend in the roll procedures see logfile 2014-04-26 13-48-10. After a few left and right rolls it broke out to the left side and couldn't catch itself. I was too late to catch it either.
The second time the AutoTune looked good the roll procedure was completed after 20sek and it switched to the pitch one. After a few pitch up and down it crashed again. See logfile 2014-04-26 13-58-29.
Luckily each times I flew over high grass so the copter was "fine" just 3 props broke...
Had never such issues with the AutoTune functions can someone look into my logs and maybe tell me what went wrong....
I had the same issue with the pixhawk since february...
I think your problem is related to the Stability Patch fixed in 3.13 and no sync issues with simonk 2014/03/06.
I have no more sync issues with the new simonk fw and 900kv motors on 3S. My problem is that my ESCs have no external oszilator and I have a huge drift on rpm when the ESCs get hot.
So I thought about to buy exactly the same ESCs as you use. Maybe you can tell me which config set you used to flash the ESCs to the latest version?
I used this to flash the ESCs:
And the "kkmulticopterflashtool_0.77beta8" software
And now I use Afro 30A ESCs
I had the same issue. Turned out to me this:
Ended up upgrading the firmware on my ESC's to the latest version of SimonK and I haven't had the issue since then.
Why should I upgrade the Firmware when just a day or two ago with 980kv motors everything went well and now with 1100kv it fails? So the Simonk is "too" slow for the 1100kv motors?
It could very well be the different motors - the APM would have a different response (in terms of stabilising the multicopter) depending on the performance of the motors.
One way to check would be to go back to your 980kv motors and see if you still have the same issue.
hmm I will first try to produce this sync issue with 0-100% throttle. After that I try to flash the ESC...
OK did now flash all the ESCs with the newest SimonK firmware.
Just went for another test and it almost happened again!
Pitch was no problem but then in the roll procedure it acted the same way as before. However the pixhawk was able to catch it this time.
So I switched to stabilize mode and did some fast roll inputs and I could see the same behavior as in the AutoTune mode.
I attached the whole log file of this flight hope someone can help me...
What do you mean by "Pitch was no problem but then in the roll procedure it acted the same way as before. However the pixhawk was able to catch it this time." ?
Did the copter take a fall and the pixhawk recovered it before it hit the ground?
yes, I switched back to manual mode and this time "I" could recover it before hitting the ground...
I had a quick look at your logs and couldn't find anything obviously wrong.
Given that your previous 980kV motors worked fine before, I suspect it might be some sort of incompatibility with the new motors.