so ive been dealing with this for like 3 weeks now and i cant figure out if its a calibration issue or if the motor is just toast. running a relatively cheap 3-axis gimbal (one of those zhiyun knockoffs from aliexpress, you know the ones) under my custom hex with a sony a6400 hanging off it. the roll axis just slowly drifts like 2-3 degrees over the course of a long hover, doesnt matter how many times i recalibrate through the app. pitch and yaw are completely fine.

i checked the balance about a dozen times, tried adjusting PID gains up and down, reflashed firmware. the drift only shows up when the motors are warm which is making me think maybe its thermal expansion messing with something mechanical. or maybe the IMU on this thing is just garbage. has anyone run into this kind of thing with budget gimbals? im not opposed to just buying something better but id like to understand whats actually wrong first before i throw money at the problem

yeah thermal drift on the IMU is absolutely a thing with the cheaper units, youre not imagining it. the sensors on those aliexpress gimbals are usually pretty low grade and once they heat up the reference point shifts. some of them have a temperature compensation setting buried in the advanced menu but honestly its hit or miss whether it actually does anything useful.

if the drift is only on roll and only when warm id also check the motor screws on that axis physically ? had one where a screw was just slightly loose and it looked like drift but was actually the motor housing flexing a tiny bit under load. probably not your issue but worth 5 minutes to check before you give up on it

what payload weight is the a6400 with lens coming out to? those knockoff gimbals usually have pretty optimistic payload ratings and if youre close to the limit the motor is probably working harder than it should which could explain why the problem gets worse as things heat up. i had a similar situation and just swapping to a lighter lens basically fixed it