Hi
Yesterday I was flying normally and switching between ALT HOLD and LOITER mode back and forth during the mission.
At the last moment I was at 80m high and was trying to come back, so I switched to ALT HOLD and cut the throttle all the way down.
It started to descend normally but some seconds later suddenly it just started to fall, at that moment I looked at the quad, it looked like one of the motors was not working as one the sides was not level as the others. I went all the way down without spinning whats so ever.
I thought maybe one of the propellers went off, but the four of them were still there when I get to the crashing place. (see picture)
I'm attaching the logs, could anyone help me solve this mystery?
Actually the same thing happen to me 6 months earlier, by the time I thought it might have been a propeller, but now I know it must be something else.
Replies
It looks like the throttle in dropped to zero and the copter started to drop, and at 70m detected a crash. But the vibrations seem to go very high just after the decent started. Something came loose?
Thank you Bill for your help.
So I've read about vibrations in http://copter.ardupilot.com/wiki/common-diagnosing-problems-using-l...
Is there anything else I can read to understand more?
Can we assume that the 70m crash heigh is because the baro was already giving bad input due to vibrations?
I really can't tell if anything came loose, the four propellers were in it's place when I found the copter, as you can see in the picture.
To plot the graphics, are you using APM Planner on Mac o Mission Planner on windows?
Bill, Dax
thank you so much for taking the time to answer!
will take note of all the advices.
I did found a screw falling of from the inside, but can't tell if it was loose before or after crash.
Do you think the lack of some of the vibration rubber on the gimbal could contribute to vibration all on the quad? (I only had two of the four installed) you can see that in the picture.
I'm using APM Planner 2.0 you can download the latest version for OSX here (it's stable) from here (it has faster log loading than previous versions)
apm_planner_2.0.19-rc4-59-gbbaa3f7_osx.dmg
The altitude reading is correct, the vibrations effect the INAV and crash detector. It looks like something came loose and the vibrations went high. It's hard to know for sure.
You can see in the alt vs GPS alt they correlate
You have to remove the sticker! It's bad luck...