Hello folks new guy here, just recently purchased a used Anycubic Kossel 3d printer. Was messing with the program Pronterface to try to get the head level with the bed. When i shift the head a certain direction the head lifts away from the bed. Is there a way to correct this issue or is it due to being a cheaper 3d printer. I havent been able to find a procedure on calibrating the head other then the screws that sets "home" on the top of the machine.