User's Manual

PMAC User Manual
Writing Programs for PMAC 187
Line
Line
Line
Line
Programmed
Path
Tool Center
Path
Line to Line Line to Arc
Arc to Arc
Arc to Line
Line
Line
Programmed
Path
Tool Center
Path
Arc
Inside Corner Cutter Compensation
r
r
r
r
Line
Line
Programmed
Path
Tool Center
Path
Arc
Arc
Line to Arc
r
r
Programmed
Path
Tool Center
Path
Arc
Arc
r
Arc
r
Arc
Arc
Figure 40 Inside Corner Cutter Compensation
Treatment of Outside Corners
For outside corners, PMAC will either blend the incoming and outgoing moves directly together, or it will
add an arc move to cover the additional distance around the corner. Which option it chooses is dependent
on the relative angle of the two moves and the value of I-variable I89.
The relative angle between the two moves is expressed as the change in directed angle of the motion
vector in the plane of compensation. If the two moves are in exactly the same direction, the change in
directed angle is 0
o
; if there is a right angle corner, the change is +/-90
o
; if there is a complete reversal, the
change in directed angle is 180
o
.
I89 specifies the boundary angle between directly blended outside corners and added-arc outside corners.
It is expressed as the cosine of the change in the directed angle of motion (cos0
o
=1.0, cos90
o
=0.0,
cos180
o
=-1.0) at the boundary of the programmed moves. The change in directed angle is equal to 180
o
minus the included angle at the corner.
Sharp outside Corner
If the cosine of the change in directed angle is less than I89, which means the corner is sharper than the
specified angle, then an arc move will be added around the outside of the corner.