Firmware Version: Arducopter 4.0.3
Airframe Type: Quadroter
Frame Size: 1500mm
Propeller Size: 30 inch
Quadcoter takeoff was stable but after 3 - 4 secs on yaw command it started wobbling agressively. Wobbling resulted in a flip and crash. Logs are avilable in the below link:
May I ask if you have followed the tuning guide that’s in the announcements section?
Your parameters are still at default settings, which, for a 30” propped copter is not going to be stable.
You need to work through the tuning guide as @philip points out and it can be found here
Also there is some problem with your motor/prop combination as seen here, major thrust loss from M3 and M4 as M1 and M2 are being shut down to compensate.
This is usually a wrong motor order, wrong motor direction, wrong props or uncalibrated ESC’s.
Also check alignment of motors and make sure they are all level.