Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 520)

Cutter Diameter Compensation
(G40, G41, G42)
Chapter 21
21-2
We use these terms in this section:
inside -- An angle between two intersecting programmed tool paths is
referred to as inside if, in the direction of travel, the angle measured
clockwise from the second tool path into the first is less than or equal
to 180 degrees. If one or both of the moves are circular, the angle is
measured from a line tangent to the tool path at their point of
intersection.
outside -- An angle between two intersecting programmed tool paths is
referred to as outside if, in the direction of travel, the angle measured
clockwise from the second tool path into the first is greater than 180
degrees. If one or both of the moves are circular, the angle is measured
from a line tangent to the tool path at their point of intersection.
r -- cutter radius
CR -- cross-point between two programmed paths after the cutter
compensation is activated
Two types of cutter compensation are available on the control:
type A (as described in the section 21.3)
type B (as described in section 21.4)
This table highlights the differences between the two types:
Type of Move Type A Type B
Entry Move Into
Cutter
Compensation
The tool takes the shortest
possible path to its offset
position. • The tool stays at least one radius away
from the start point of the next block at
all times.
• Extra motion blocks can be generated
to attempt to prevent gouging of the part
as may occur in Type A.
Tool Path Same
Exit Move From
Cutter
Compensation
The tool takes the shortest
path to the end-point of the
exit move for both inside and
outside corners. • The tool takes the shortest path to the
end-point of exit move for inside
corners only.
• For outside corners, the tool stays at
least one radius away from the
end-point.
The system installer determines whether type A or type B is used by a
control in AMP.