Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 585)

Compound Turning Routines
Chapter 24
24-21
Figure 24.15
Effect of Positive and Negative Finish Allowance Parameters
A A
B B
X
Z
C
C
C
C
A A
B B
U(+), W(+) U(+), W(-)
U(-), W(+) U(-), W(-)
In Figure 24.16, the workpiece contour is illegal for the G74 roughing
routine and may not be cut. When this cycle is used to cut a contour the X
axis motion must either constantly increase or constantly decrease. No
reversal is allowed on the X axis.
Figure 24.16
Illegal Contour for G74 Rough Facing
X
Z
X motion is not continuously
decreasing or increasing