Screws

there have been a LOT of people saying that their printer has loose hardware which would not be unheard of, especially if you live in the US and the printer was shipped from over seas. A few main items to check are the screws that attach both the motor to its mounting plate and the screws that attach the mounting plate to the printer tower/leg. Just be careful not to tighten the four motor screws too tight as there is a cork gasket that acts as a vibration damper for each motor. Tightening these screws too tight will cause excess vibrations and may add artifacts to your prints as a result.