Unstable Flight and Sudden Drift After Autotune on 7" Quad – ArduCopter 4.5.7

Your Builds Multirotor
1

Today, I flew my 7" quadcopter running ArduCopter version 4.5.7. When I increased the throttle, I noticed significant vibrations causing the quad to oscillate up and down. However, after reaching a certain altitude, it became stable, and I was able to successfully complete an autotune.

Log:

https://www.dropbox.com/scl/fi/5not8atjshq3gm47wtskg/2025-05-12-06-30-36-AutoTune.bin?rlkey=3z4noccuia7rub2x0ov657wti&st=an3mw1u9&dl=0

After that, I disarmed the quad and disconnected the battery. On the next flight, after reconnecting the battery and arming the quad, it exhibited uncontrollable vibrations and suddenly moved rapidly in one direction. In a panic, I disarmed it immediately.

Log:

https://www.dropbox.com/scl/fi/3xdb3d821vesyvg7jtc32/2025-05-12-06-50-30-UncontrolledDisarm.bin?rlkey=tby6jubt64aokw5qsgscejhpn&st=wna3uwf0&dl=0

Video:

Please check the system logs and help me understand what went wrong.

2

You already posted on the Ardupilot forum, I think you will find your answer there.

3

Sure I am following that thread, meanwhile when you get free time request you to check log file for any major mistakes I made.