Violent Auto/Loiter Event - Logs Attached

I have reassembled two Vulcan Hexacopters with KDE Motors and Pixhawk Cube (2.1) I have flown this unit dozens of times without any problems. I have updated the ESC firmware. I also preformed all the required steps as if this was a new build. I was going to test a small AUTO mission at 24 feet and it wobbled and swayed to the extreme. Any help on these LOGS would be great!



To me it looks like the RC inputs are going a bit more extreme than what I’d expect for a hover/flight test. Particularly yaw. (I could be wrong)
Also the battery voltage monitoring is a bit off, the voltage is rising over time, as is the Vcc (5 volts).

You could try:
and see if that smooths things out the RC input response too.

There’s some other parameters that look off to me. Assuming about 15inch props try these as a starting point:
MOT_BAT_VOLT_MAX {4.2xLiPo cells}
MOT_BAT_VOLT_MIN {3.5xLiPo cells}

Let us know more of the exact specifications if you want to, and how it goes with checking the RC channels and other parameters.

…and probably set
and do another Autotune, 1 axis at a time, or maybe pitch and roll together and yaw seperate.

I’m going to completely retune one of the copters but it looks like some of my RC numbers are off. These ESC’s are OneShot with 1100 to 1940 hard input. My motor numbers are way off this. I had these sent back to me in a golf case. These are copters that aren’t supposed to be folded. One came from NY and one from Brazil. I had built and tuned them 2 years ago. Nothing odd with the GPS?

There could be more issues that I didnt see, and maybe what I pointed out is not critical. It’s just what I could see and what I’d start with. :slight_smile:
Altitude and baro looked a bit odd.

For MOT_BAT_VOLT_MIN make it 3.2 x no. of LiPo cells, not 3.5

Ok. I will check that. I have two 10000 mah for a total of 6 cells.

Please watch this quick video. It may shed light on what is happening. I have 3 copters that were shipped to me that are now knocking like this.


Strange! Seems like a desync issue although I’ve got limited experience with that.
Even though you’re on ArduCopter V3.6.7, I’m tempted to point to this thread:

Otherwise it’d have to be ESC settings I’d think…

I have a ticket in with KDE Motors. I doubt it is damage from transport. I think it is bad firmware. I am hoping to dial it back. Thanks for all your time!

PS: I had just blanked out this copter and started from scratch. This now has 4.0.1 on it. The other copters still knock though, they are on V3.6.7 - After firmware update.

Just rolled back to v3.6.9 and the knocking is gone! Weird. Not sure if that will help the LOITER issue but it’s a start.