Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 519)

Chapter
21
21-1
Cutter Diameter Compensation
(G40, G41, G42)
To cut a workpiece using the side face of the cutting tool, it is more
convenient to write the part program so that the center of the tool moves
along the shape of the workpiece.
Since all cutting tools have a diameter, a program written for moving the
center of the tool will not cut the workpiece to the proper size. To produce
a workpiece that has the correct size, offset the path of the tool center from
the shape of the workpiece by an amount that equals the radius of the tool.
The control offers a function, called cutter compensation, for offsetting
tool paths by the amount of a tool radius. Put the radius of the tool into the
offset tables in advance (see section 3.1 or 20.5). This function lets the
control use the same program to produce the same workpiece regardless of
the radius of the tool that does the cutting.
Figure 21.1
Tool Radius Diameter Compensation
workpiece
programmed path
tool center path
cutting
tool
21.0
Chapter Overview