Massive arducopter yaw instability

ArduCopter Copter 3.4
1

Hi,
I built a quadcopter that was working very well until I recently started it up for the first time in a while. Suddenly a bunch of Yaw instability appeared. When flying normally or just hovering the quadcopter would randomly Yaw and if it was stabilising out of a pitch/roll then it would also have a massive yaw flip out. I thought it was tuned incorrectly, however, the quadcopter was working before and I also ran autotune which gave similar PID’s as before so I’m not sure whether this is the issue.
Then today I took it out and it just went crazy. I’ll attach the logs and they are really worth taking a look at. The throttle in was jumping up to 2000, then dropping below 900 every second. I have no idea why this is, but naturally, it ended up in a massive crash that has busted my quadcopter badly.
If anyone can help, that would be very much appreciated.
Thanks in advance,
Boris

2016-09-25 15-13-41.tlog (1.5 MB)

2016-09-25 14-53-31.bin (105.2 KB)

2

Just FYI to devs I’ve had that happen with 3.4 rc1 Sorry I don’t have a log though

3

You seem to have vibrational spikes just before the roll and pitch diverged.

Screen Shot 2016-10-10 at 6.23.28 am.png2478×822 213 KB

There are also random vibrational spikes in your acc data.
Something loose on the quad?

Your .bin file would provide more telling information.

4

Any chance you could find a dataflash log? They have so much more info that it makes analysis much easier.

5

Hi,
Thanks for your help and I’ve attached the bin file here, as well as the tlog.
There was a lot of instability the whole flight, and I had zero control the entire time.

2016-09-25 15-13-41.tlog (1.5 MB)
2016-09-25 14-53-31.bin (105.2 KB)

6

and the log fille

2016-09-25 14-53-31.log (232.7 KB)