@taroh is right.
Take it easy: IMU doesn't have nothing to do with aluminium in any way. Accelerometers and gyroscopes AREN'T sensible to metals, they are MEMS (mechanical). Just keep away from magnets (aluminium is not magnetic). IMU need flat and leveled plane surface and temperature must be the one of you bird just switched on, not after a flight or when p3 is hot for any reason.
BUT I don't really know what kind of IMU is using DJI, because many IMU has magnetic field sensors of 3 DOF (X,Y,Z) inside!
Anyway, compass dance is relative to a separate DJI sensor in any case, and DON'T calibrate it on a aluminium table (or tinny place), because it is conductive and can deflect earth field!
Just to explain, the problem is not the magnetic effect, but tinny surfaces deflect and modify the earth magnetic field, that's why compass can get poor calibrated.
COMPASS sensor:
GOOD:
BAD:
NOISE:
Take it easy: IMU doesn't have nothing to do with aluminium in any way. Accelerometers and gyroscopes AREN'T sensible to metals, they are MEMS (mechanical). Just keep away from magnets (aluminium is not magnetic). IMU need flat and leveled plane surface and temperature must be the one of you bird just switched on, not after a flight or when p3 is hot for any reason.
BUT I don't really know what kind of IMU is using DJI, because many IMU has magnetic field sensors of 3 DOF (X,Y,Z) inside!
Anyway, compass dance is relative to a separate DJI sensor in any case, and DON'T calibrate it on a aluminium table (or tinny place), because it is conductive and can deflect earth field!
Just to explain, the problem is not the magnetic effect, but tinny surfaces deflect and modify the earth magnetic field, that's why compass can get poor calibrated.
COMPASS sensor:
GOOD:
BAD:
NOISE: