Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 522)

Tool Tip Radius Compensation (TTRC)
Function
Chapter 21
21-38
Figure 21.32
Results of Example 21.14
Point 2
Point 1
N21 (G42)
Compensated
path
Programmed
path
N20 (G41)
For one of these cases that changes the TTRC direction, the control
attempts to find an intersection of the actual compensated tool paths:
Linear-to-Circular, Circular-to-Linear, or Circular-to-Circular 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 21.33.
Figure 21.33
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 the same as if a linear-linear intersection had taken place. See
Figure 21.34.