Plane Handling - Arcs
The standard planes for CNC machine tools that follow the Right Hand Rule are:
• G17 (XY Plane)
• G18 (XZ Plane)
• G19 (YZ Plane)
Following standard convention you view a plane by looking down the vector of the plane from the positive side looking at the origin.
To explain that in more detail, look at the image above. If we are looking at the G18 plane, we would look at that plane from the Y+ coordinate looking to the origin. The result of this has us looking at the Back face of a standard cube. When looking at the G19 plane you are looking from the X+ coordinate looking to the origin which has us looking at the Right face of a standard cube.
For standard CNC controllers that follow the Right Hand Rule you determine the arc direction of G2(CW) and G3(CCW) by looking from the Top(G17), Back(G18), and Right(G19) views.
Alternate Views
When looking at views that are opposite of the plane it is important to understand the arc directions are reversed.
