The measurements on the cube may be due to excessive wobble in the x/y axis. Does your printer have a moving bed or does the nozzle move? If it’s a moving bed then there is extra weight that the motors, belts and rails need to deal with so might be worth lowering your print speed or acceleration or both. Mine is a moving bed and I don’t print any faster than 40mm/s because of the extra weight.
Reply To: HELP Can't make square cuts