Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 592)

Using Pocket Milling Cycles
Chapter 22
22-20
Important: The tool should be positioned near the center of the pocket
prior to the G88.2 block. The Z coordinate of this position determines the
initial Z level or top of the pocket. This is the pre-cycle position of the
tool. The pre-cycle position must be at some depth other than the cycles
programmed final depth or an error is generated.
Except for the shape of the pocket, the rest of the circular pocket finishing
cycle is identical to that of a rectangular pocket finishing cycle.
Use the G88.2 pocket milling finishing cycle to finish a slot in a
workpiece. This cycle is typically used to remove the finish allowance that
was left on the sides of a slot during a G88.1 cycle.
The G88.2 block used to finish a slot has this format:
G88.2 X__Y__Z__I__R__P__H__L__F__; (X axis slot)
or
G88.2 X__Y__Z__J__R__P__H__L__F__; (Y axis slot)
Where : Is :
X Y The coordinates that specify the center of the slot.
Z The coordinate (along the plunging axis) that specifies the bottom of the slot.
I J The length of the slot as measured from the point where the axis intersects the
arc at each end of the slot. I specifies the length of a X axis slot. J specifies the
length of a Y axis slot. These are unsigned incremental values.
R The radius of the arc at each end of the slot. The radius equals the slot-width/2.
If not programmed, the control uses the tool radius value.
P Direction of finishing cut.
H Finish allowance.
L Incremental plunge depth.
F Finishing feedrate.
Important: The tool should be positioned near the center of the pocket
prior to the G88.2 block. The Z coordinate of this position determines the
initial Z level or top of the pocket. This is the pre-cycle position of the
tool. The pre-cycle position must be at some depth other than the cycles
programmed final depth or an error is generated.
22.2.3
Slot Finishing Using G88.2