Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 556)

Cutter Diameter Compensation
(G40, G41, G42)
Chapter 21
21-38
For one of the following cases that changes the cutter compensation
direction, the control will attempt to find an intersection of the actual
compensated tool paths:
Linear-to-Circular, Circular-to-Linear, or Circular-to-Circular Tool Paths
For the following cases that change the cutter compensation direction, the
control attempts to find an intersection of the actual compensated tool
paths. If the control finds an intersection, it modifies the end-point of the
original compensated tool path and the start-point of the new compensated
tool path to equal that intersection. (see Figure 21.34).
Figure 21.34
Change in Compensation With Actual Tool Path Intersection
G42
G42
G41
Programmed G42
Compensated path G41
Programmed path
r
+
+
r
r
r
+
+
Programmed
path
Compensated
path G41
Compensated
path
If no intersections of the actual tool paths exist, the compensated tool path
is as shown in Figure 21.35. The end-point of the last move in the original
compensation direction is at right angles to that block’s programmed tool
path, and the start-point of the move in the new compensation direction is
at right angles to that block’s start-point.