Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 553)

Cutter Diameter Compensation
(G40, G41, G42)
Chapter 21
21-35
The following subsections describe possible tool paths that may be
generated when programming one of the following during cutter
compensation:
changing cutter compensation direction (cross-over tool paths)
exceeding the allowable number of consecutive non-motion blocks
during cutter compensation
corner movement following a generated block
changing cutter radius during cutter compensation
effect on cutter compensation when interrupting a program to execute
either a MDI program or a manual move
changing or offsetting current work coordinate system during cutter
compensation
moving to and from machine home and secondary machine home
This section describes the resulting tool path when a change in
compensation direction (left or right) is programmed. This may result in
the cutting tool crossing over the programmed tool path as compensation
changes from left to right or right to left.
Linear Tool Path-to-Linear Tool Path
The following figures show the tool path taken when cutter compensation
is changed from G41 to G42 during the execution of two linear program
moves.
The control generates two points when changing cutter compensation
direction, called point 1 and point 2. Point 1 is the final tool position
before compensation direction is changed (at right angles to the end-point
of the programmed tool path offset by one tool radius). Point 2 is the
desired tool position for the start of the first block using the changed
compensation direction (at right angles to the start-point of the motion
block that changes compensation direction and offset by the tool radius).
The control generates the motion block that connects point 1 to point 2 as
shown in Figure 21.30 through Figure 21.33.
21.6
Cutter Compensation
Special Cases
21.6.1
Changing Cutter
Compensation Direction