Frame: Hobbyking X666 with double motor mounts
Motors: SunnySky X2212 980kv
ESC: Afro ESC 20A Simonk
Props: GemFan T-motor style 13x5.5’ Carbon
Battery: 2x Turnigy Nano-Tech 6000mAh [ 5700mAh measured from 4.2->3.6v]
FlightController: Pixhawk with Arducopter 3.1.4
Reciever: FrSky D8R-II Plus + PPM Encoder
It was a never crashed build until today. It was moderately new, having between 4 to 5 hours of flight.
I’ve started flying multis around an year ago, since Portugal has nice weather and I can fly at walking distance from home I’ve hundreds of flight hours already. I’m quiet used to build multis, I’ve built and flow quads, hexas, octos (I really need a tri!!).
Usually I fly with KK 2.0 boards (so used to Acro/Stabilized modes) or un-Autonomous boards of the sort, Pixhawk is the most advanced controller I’ve had the chance to fly. Due to my area of work/study I had no problems getting used to it and having it flying properly.
I flew around one of my usual spots for around 11minutes. Since I got the 30% battery warning and my voltage was already at ~10.6 I was heading home. The whole time I was flying the rig fpv. Neither the low voltage onboard alarm (set to 3.5v per cell) nor the Pixhawk voltage alarm (set to 10.6) made any sound.
What I felt was a loss of both power and attitude, I didn’t had fast enough reflexes to change from AltHold to Stab but I did give it full throttle. The craft went down either way. Luckily it felt in 1m high tall grass so not even a single prop broke, the only damage done was my home made aluminum landing gear and my GPS post, I ended up losing my FVP TX antenna top but who cares…
(Jump to the last few seconds to see the fall or enjoy the whole trip)
Comments about the video:
- Loss of power (no motor sound)
- Pixhawk turn on sound
- Motor rotate for a little bit (?!?)
- Puff ground.
After Crash Photos:
Upon inspection craft looked okish. Only thing that cough my eye was that my XT60 parallel connector was loose from the ESC input, I don’t know if it either happened because of the fall or it mid flight (less likely... do XT60 come loose ???).
When does the Pixhawk reboot? I’ve it powered by both the power module and the ESC UBEC to have power redundancy. If one of this power sources fail (for example the ESC UBEC) does the board reboot (this would be really weird...) or it keeps on running from the power module power?
I couldn’t find anything wrong on the logs and that’s worrying me...
I need help analyzing this crash since for the first time I don't know for sure what went wrong.