There was a question in the G+ on g-code to be used for leveling the z-axis. At this point, I'm using Pronterface, so I created a button that moves right and left while giving the height of the bed. Then, with power off to the motors. the lead screw can be adjusted until the reading is the same on both sides. This macro does not set the y-axis because I want to be able to measure in the middle and at the extreme and minimum y locations but it could be easily changed to do that. button 8 "Z SLIP" /c "Blue" slip macro slip G1 X2 Z10 F9000 G30 G1 X190 Z10 F9000 G30 Be sure to turn power to the motors off and watch the axis that you are not turning. If you turn one axis too quickly, I've seen back EMF go through the other driver and cause that one that you are not moving to go up or down. Often, I just hold one steady and turn the other one.