Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 582)

Using Pocket Milling Cycles
Chapter 22
22-10
If L is programmed, the tool plunges along the Z axis to the incremental
depth specified by the L parameter. If L is not programmed, the tool
plunges along the Z axis to the pocket depth specified by the Z parameter.
The plunge takes place at the plunge feedrate specified by the E parameter.
After the plunge operation a roughing cut is made at the feedrate specified
by the F parameter to the arc-center at the +X or +Y end of the slot.
A plunge to the next incremental L level or to the programmed Z level is
made. A roughing cut is made at the feedrate F to the arc-center at the -X
or -Y end of the slot. This process is repeated at each L level until the slot
is machined out. When the slot is machined out the control raises the tool
to the initial Z level plus the clearance amount and then moves it to the
pre-cycle position of the tool.
Use the G88.1 pocket milling roughing cycle to rough out a circular pocket
in a workpiece. This cycle makes multiple circular cuts at a programmed
width and depth.
The G88.1 block used to rough out a circular pocket has this format:
G88.1 X__Y__Z__R__P__H__D__L__E__F__;
Where : Is :
X Y The coordinates that specify the center of the circular pocket.
Z The coordinate (along the plunging axis) that specifies the bottom of the circular
pocket.
R The radius of the circular pocket. This parameter must be programmed.
P Direction of roughing cut.
H Finish allowance.
D Roughing cut thickness.
L Incremental plunge depth.
E Plunge feedrate.
F Roughing feedrate.
22.1.4
Circular Pocket Roughing
Using G88.1