FlashCut is the software used to control the milling machine. Toolpaths generated from CAM software or directly coded using G-code are transformed into actual movements of the tool by this program.
One must zero, and in some cases rezero the tool during the course of fabrication. The upper right hand section of the FlashCut Window has 4 sets of coordinates (Each set comprised of X, Y, Z, and Angle). The only one of interest is the "Program" coordinate set (highlighted in the red box). There are two buttons next to the title, "Set" and "0". "Set" allows the user to manually establish the coordinates of the tool. This is useful when the offset of a tool must be accounted for. "0" simply zeros all of the coordinates.
This mode is the interface used when setting up and running G-code in the program. Double clicking on the bottom left window of the program opens a new window to write or edit G-code. The toolpath specified by the code present in the bottom left window is shown in the top left set of windows. This allows the user to get a broad look at what will happen when the code is executed. Control over execution speed and the method in which the code gets executed (continuous vs step by step) is in the bottom right corner. Once the start button is clicked, execution begins immediately. The program pauses during execution when any key is pressed.
This is an easy way of directing the tool to a specific coordinate. Be sure to check all of the coordinates as well as the speed, since it will go in a direct path to the coordinates you specify.