Are you ready to dive into the fascinating world of CNC machines? If you’re curious about how these complex machines work, then you’re in the right place.
One of the fundamental concepts in CNC machining is the origin, which forms the starting point of the machine’s coordinate system. But what exactly is the origin, and why is it so critical to the CNC machining process?
In this article, we’ll explore the definition of the machine origin, reference points, and coordinate system of CNC machine tools. We’ll also delve into the principles behind choosing the workpiece origin or workpiece zero point, and the factors that affect its selection.
Whether you’re a seasoned CNC machinist or just starting in the field, this article will provide you with valuable insights into the complex world of CNC machining.
So, let’s get started!
1. Machine origin and reference points of CNC machine tools
The origin of a CNC machine, also referred to as the mechanical origin, is the starting point of the machine’s coordinate system. This fixed point is determined by the machine’s design and manufacturing, and cannot be changed by the user.
The machine tool origin serves as the reference point for the workpiece coordinate system, the programming coordinate system, and the machine tool reference. It should be noted that the machine tool origin is not a physical hardware point, but rather a defining point in the machine’s coordinate system.
In CNC machines that use incremental measurement, the machine origin is reflected by the machine tool reference point. This reference point is a physical hardware point and is unique to CNC machines.
2. CNC machine tool coordinate system
The origin of the workpiece coordinate system is known as the workpiece origin or the workpiece zero point. This coordinate system is set artificially and has several principles for choosing its origin:
- If possible, the origin is selected based on the workpiece pattern to simplify calculations and reduce programming errors.
- If possible, the origin is selected on a surface of the workpiece with high dimensional accuracy and low roughness to improve machining accuracy.
- The origin should be easily measurable and inspectable.
- For symmetrical workpieces, it is ideal to choose the symmetrical center of the workpiece.
- For general parts, the origin should be selected at a corner of the outer contour of the workpiece.
- The origin of the Z-axis direction is typically located on the surface of the workpiece.