so ive been fighting this for like three weeks now and im at the point where im just going to post about it because google isnt helping. running a custom hex with a zenmuse x5s knockoff style 3-axis gimbal, not the actual DJI one, one of the aftermarket units from a supplier i wont name. the roll axis specifically keeps drifting over time, like its fine when i arm it and do the auto calibration but after maybe 4-5 minutes of flight it starts creeping maybe 2-3 degrees off horizon. doesnt matter if im hovering or moving.

ive already rebalanced the camera like four times, checked the IMU on the gimbal controller, reflashed the firmware. the weird thing is if i land and let it sit for a minute and re-arm it recenters fine. so its not a mechanical bind or anything. feels like thermal drift maybe? the controller board is tucked pretty close to one of the ESCs so it gets warm during flight. anyone dealt with this before or am i just chasing my tail here.

thermal drift is definitely a thing on cheaper gimbal controllers, the gyros on those budget units are not great and they do shift with temperature. id try relocating the controller board first, even just adding some standoffs to get airflow around it. also check if your gimbal has a PID tuning interface because sometimes the I gain being too high will cause that slow creep behavior even if calibration looks fine on the ground. the symptom you're describing where it resets fine after a cool-down break is pretty classic thermal issue honestly.

had something similar on my old tarot gimbal, turned out one of the motor phases was intermittently dropping connection due to a cold solder joint. only showed up once things warmed up and the solder expanded slightly. probably not your issue but worth a visual inspection with a magnifier if the thermal relocation doesnt fix it.