Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 605)

Using Post Milling Cycles
Chapter 23
23-11
Use the G88.4 post milling finishing cycle to finish a circular post in a
workpiece. This cycle is typically used to remove the finish allowance that
was left on the sides of a circular post during a G88.3 cycle.
The G88.4 block used to finish a circular post has this format:
G88.4 X__Y__Z__Q__R__P__H__L__F__;
Where : Is :
X Y The coordinates that specify the center of the circular post.
Z The coordinate (along the plunging axis) that specifies the bottom of the circular
pocket.
Q Unsigned incremental value that specifies the distance from the sides of the
circular post to the outer perimeter of the circular pocket.
R The radius of the circular post. This parameter must be programmed.
P Direction of finishing cut.
H Finish allowance.
L Incremental plunge depth.
F Finishing feedrate.
In a finishing cycle, a smooth entry to and exit from the finish contour is
accomplished by having the tool approach and leave the finish contour
along a tangential arc. The radius of this arc is set equal to the tool radius
by the control. The tangential entry and exit will always occur on the left
side of the circular post at the -X axis.
23.2.2
Circular Post Finishing
Using G88.4