Help w/ log analysis - copter flip/crash

My copter has been occasionally dropping to the side and crashing.
Could someone help diagnose the issue in my logs?

In this log, I have my flight controller hard mounted and don’t have very good props on, so the vibes are bad. But, this issue was happening w/ the soft mount, too, where vibes were very low. (This is a test platform, so I’m trying different things. I’ve obviously got to go back to the soft mount, but that’s not what is causing this particular issue.)
I’d appreciate it if someone could help me figure out the crash issue… I’m guessing an ESC at the moment, but I don’t know enough about log analysis. The crash is around line 69 in the log.2017-03-21 09-49-34.bin (2.6 MB)

Thank you.

(Edited to say, i did go over the basics as best I could, and do see the desired roll does not change while the actual roll shows it flipping… But I’m not completely clear on how to determine which motor/esc had the issue, or if something else was happening… When it happens (assuming there’s no damage) I can simply re-arm and take off again. Thanks again)

Actually, I think I solved it… I wasn’t sure what is right/left or forwards/backwards in the logs… But mapped my RCOUT and see motor 4 was the first to get full throttle.
That’s the oldest ESC on this copter… The rest have failed over the years… SO, that’s probably it.

Right, It looks like motor 4 has stalled and motor 3 was set to minimum to keep it upright.

Mike

Thanks for looking and confirming my analysis.