so ive been running a Gremsy T3V3 with a Sony A7III for a few months now, pretty happy with the setup overall. decided to swap out to a lighter mirrorless ? the Fuji X-T4 ? because i wanted to push the flight time a bit and the A7III rig was sitting at like 1.2kg with the lens attached.

after the swap and re-balancing the gimbal, im getting this slow roll drift. like maybe 2-3 degrees over the course of a minute, its not dramatic but you can absolutely see it in the footage if you're doing a long slow pan. re-did the balance twice, checked the IMU calibration in the Gremsy app, nothing seems obviously wrong. the Fuji is actually a bit lighter so i thought it would be easier on the gimbal motors not harder.

anyone dealt with this before? im wondering if its a PID tuning thing or if the weight distribution is different enough that the gimbal is just fighting itself slightly. havent touched the PID values yet because honestly i always break more than i fix when i go in there

yeah the drift thing with gremsy when you change payloads is almost always a PID issue in my experience. the auto-tune is okay but it doesnt always nail it when the weight distribution changes significantly, even if the total weight is similar. the fuji has a different center of mass compared to the sony body so the motors are working differently to hold position.

what i usually do is run the auto-tune first then tweak the roll axis stiffness up maybe 10-15% manually. slow drift like what you're describing is usually the stiffness being too low, the motor just gradually loses the fight against gravity. also double check that your motor power settings didnt reset after the firmware ? gremsy has done that to me before and it drove me insane for like two days before i figured it out

might be worth checking if the quick release plate is fully seated too, i know that sounds dumb but i had a similar drift situation and it turned out the camera wasnt clicking in all the way and there was like half a mm of wobble. not enough to see by eye but enough to mess with the IMU readings. probably not your issue but worth 30 seconds to rule out