Understanding the Homing Procedure
Whenever you open UCCNC, the very first movement you should make with your machine is "Home All". On a STEPCRAFT, the homing procedure begins with the Z-Axis, then the X-Axis and finally the Y-Axis. Each axis will run towards its limit switch until it engages the switch, then will run the opposite way until the switch disengages. Once all three axis have hit their limit switch, your machine is now ready to travel the full length of each axis!
This is known as a reference movement for the machine. Without this reference movement, the machine has no idea where it is along its axis and may not travel the full length back and forth. If your machine is stopping short of the full length of travel and you aren't noticing any binding, make sure to "Home All" and try running again.
One important thing to note is that if any axis ever travels in the opposite direction of its limit switch when homing, check to make sure a limit switch is not engaged somewhere on the machine. All of the limit switches are on the same circuit, so if you tried to home your machine and the Y-Axis limit switch was pressed, the Z-Axis would travel in the OPPOSITE direction. This happens because the machine is going through the stage of homing when it backs away from the switch until it disengages. Because the Y-Axis switch was pressed, the Z-Axis will infinitely try to move away but it will never disengage.