It can have many, many reasons.
Please provide more information. photos, .bin log files, FW versions, etc.
And read How to methodically tune (almost) any multicopter using ArduCopter 4.4.x before posting other questions.
It can have many, many reasons.
Please provide more information. photos, .bin log files, FW versions, etc.
And read How to methodically tune (almost) any multicopter using ArduCopter 4.4.x before posting other questions.