so ive been dealing with this for about three weeks now and i cant figure out if its a calibration issue or something hardware related. running a DJI O3 air unit with a custom gimbal mount i printed, and the horizon just slowly rolls to the left during longer flights. not like instantly, it kind of creeps over maybe 5-10 minutes into the flight and then holds there. its subtle but you can def see it in the footage.

ive recalibrated the IMU like four times, redone the gimbal balance, even swapped the ribbon cable thinking that might be it. the gimbal itself is a fairly cheap two-axis unit so maybe thats just the answer and i need to accept it lol. but thought id ask before i drop money on something better. anyone seen this kind of slow drift before or is it just a trash gimbal situation

yeah two-axis gimbals are just kind of infamous for this, especially on longer flights when the motors start warming up a bit. the yaw axis on cheap units has pretty weak holding torque and any slight imbalance gets amplified over time. if your camera isnt perfectly centered on the roll axis it will literally just slowly rotate to find its happy place.

honestly if your gimbal doesnt have adjustable PID settings you're kind of stuck. the nicer units like the Movi or even the Zhiyun stuff lets you tune the motor strength to compensate. what gimbal is it exactly? if its one of those generic AliExpress ones the firmware is usually locked anyway so you cant do much. might just be time to move up, a three-axis makes a massive difference especially for any kind of longer duration flying

random thought but did you check if the mounting plate is actually rigid? i had something similar and it turned out my 3d printed mount had just a tiny bit of flex in it and over time vibration was letting the whole assembly shift slightly. put a piece of carbon fiber plate under mine and it basically stopped. probably not your whole problem but worth checking before spending on a new gimbal