On some machines thereвЂ™s an entire servo system in place that makes this entire process incredibly fluid and precise. For some machines there is a physical limit switch that signals the controller that a machine has reached an axis limit. Under the hood, the process can vary from machine to machine. When this occurs for all three axes, the machine is now вЂњhomed.вЂќ Once a limit is reached, a signal is sent to a controller which records the home position for that particular axis. When this process occurs, all three axes of your CNC move towards their maximum mechanical limit. When your CNC first boots up, it has no idea where it is in physical space and requires a calibration to get its bearings. Check out the video below from Robert Cowan to see this in action:Д®very CNC machine has its own internal origin point called Machine Home. Understanding the difference between the movement of your tool and table is easier to show than explain with words. If reading that left you more confused than before, donвЂ™t worry. You are cutting into the piece which corresponds to a negative Z axis coordinate. Increasing the Z axis coordinate would move the spindle up, decreasing it would move it down into a workpiece. For example, increasing the X coordinate value moves the table left, but looking from the perspective of the tool, itвЂ™s moving right along a workpiece. The movement of your CNC along the coordinate system is always based on how your tool moves, not the table. If only it were as simple as shoving a block of metal into your CNC and pressing go. To do this, the machine needs to understand the position of the stock in physical space. However, something like a milling machine has to subtract material away from an external object. ThereвЂ™s no question about where the piece starts on the build plate. Why Do Coordinates Matter for CNC Milling?ДЄdditive machines build a part from the bottom up. In this article, weвЂ™ll be covering the basics of the CNC coordinate system, including the Cartesian coordinate system, work coordinate system (WCS), and offsets. The technology might change, but the fundamentals remain essentially the same. Even the latest CNC machines are the same at their core: they use an X, Y, and Z-axis to define the coordinate space inside the machine, and a tool (sometimes an endmill, sometimes an extruder, sometimes a laser beam) moves around that space. YouвЂ™ll use your CNC milling coordinate system fundamentals everywhere, not just for one particular CNC machine.

Grbl controller machine coordinates