Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 572)

Compounding Turning Routines
Chapter 24
24-8
Figure 24.4
Effect of Positive and Negative Finish Allowance Parameters
Z
X
B
A C A C
B
U(-), W(-) U(-), W(+)
U(+), W(+) U(+). W(-)
B
A C C A
B
The workpiece contour in Figure 24.5 is illegal for the G73 roughing
routine and may not be cut. When this routine is used to cut a contour the
Z axis motion must either continuously increase or continuously decrease.
No reversal is allowed on the Z axis.
Figure 24.5
Illegal Contour for G73 Roughing Routine
X
Z
Z motion is not continuously
decreasing or increasing