Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 624)

Irregular Pocket Milling Cycles
Chapter 25
25-6
Figure 25.3
Roughing-Out Adjacent Areas in an Irregular Pocket
TOP
VIEW
Start/end corner
H
X
Y
Y X
Z
U/W
T
Q
N R
O
P S
V
If there is no undone area within one cutter radius of the current cutter
position, the control raises the cutter to the initial Z level (point O in figure
16.19). The cutter is then moved at the rapid feedrate to the nearest
position just outside the nearest undone area (point P) and lowered to the
current plunge-level minus the clearance amount (point Q) at the rapid
feedrate. The clearance amount (e) is AMP selectable, refer to the
literature provided by your system installer. The cutter is then lowered to
the current plunge-level (point R) at the plunge feedrate.
Important: The control will move the cutter to the nearest undone area
without raising the cutter to the initial Z level if it can do so without
interfering with a pocket wall. In this case, the control will raise the cutter
the clearance amount (e) and move it to the new position. The cutter is
then lowered to the current plunge-level at the plunge feedrate.
The area within one cutter radius of the current cutter position will be
machined-out in a series of straight-line step-over roughing passes. The
orientation of these passes, either parallel to the X or the Y axis, is
dependent upon the pocket contour. The control determines whether
passes parallel to the X or to the Y axis will machine-out the most material
in the fewest amount of passes and orients the passes accordingly (R
through X in Figure 25.4).