Pixhawk autotune crash

Can one of you have a look into my logs, did a autotune and after a few seconds the quad crashed upside down, autotune started also very aggressive compared to other autotunes

Loiter and althold was ok

Search for motor sync , bad ESC/battery voltage/motor/prop combination is a common reason.

Hi Andre,

pixhawk with 3dr powermodule on 4s, hobbyking afro esc 30a with sunnysky 2212 980kv, is this a known pixhawk problem config?
Same config was working 100% with 3dr apm

search, and test. yes, it sounds like a configuration thats prone to this failure.

The general consensus on this type of crash is that it is caused by ESC sync issues or other hardware failure.

Change to APM perfect flights, back to Pixhawk without any hardware changes flips and sync errors
What is different for sync esc steering between apm and pixhawk.


Here is the fix to most esc sync issues for the Awsome PixHawk;))

For some reason on the PixHawk you have to connect all 3 wire ESC BEC’s to the pixhawk to avoid the sync issues. That means the (Signal,V+,and Grnd) for all 4,6,or 8 ESC’s.

I had the same issue using the ppm converter (please don’t use) and or the esc only using one ground,v+, and signal and the rest just signal. It causes a de-sync and the multi rotor will flip, pitch, or roll at any given moment.

I solved it by using all 3 wire BEC leads. I have 14 Pixhawks running and no issues since. Very Solid Performance.

BTW Afro’s @#$K anyway… My 2 cents…

Hope this helps guys;))

It isn’t PIXHAWK’s fault. You must provide a signal ground on any flight controller - anything else is unsafe. You don’t have to connect the center wire (5v) if you don’t want to. Doesn’t seem to hurt anything, though. You might want at least one connected, if you want to take advantage of PIXHAWK’s ability to fail over to a different power supply.

Just because the horribly bad practice of connecting signal only works “most of the time” with one FCU, doesn’t mean you can just haphazardly assume that you don’t need those other wires.

A very sad incident happened with my hex :sob:, it crashed in lake while doing auto-tune in Alt Hold mode.
Previously I did auto-tune,but that was with loiter mode, so today morning there was no wind, so i planned to do auto-tune in alt hold mode, unfortunately it went toward lake which near my farm, and collapsed inside lake,with help of dive(paying 40$) i found it, it was inside lake till 4.30pm from approx 7.30am.
Sharing log file :sob: