User's Manual

PMAC User Manual
192 Writing Programs for PMAC
Note that few controllers can make their lead-out move a CIRCLE-mode move. This capability permits
releasing contact with the cutting surface very gently, important for fine finishing cuts.
Inside Corner
If the last fully compensated move and the lead-out move form an inside corner, the lead-out move starts
directly from this point to the programmed endpoint. When the lead-out move is a LINEAR-mode move,
the compensated tool path will be at a diagonal to the programmed move path. When the lead-in move is
a CIRCLE-mode move, the compensated tool path will be a spiral.
Line to Line Line to Arc
A
rc to Arc
Arc to Line
Removing Compensation – Inside Corner
Line
Line
Programmed
Path
Tool Center
Path
Arc
Arc
r
Line
Line
Line
Line
Programmed
Path
Tool Center
Path
r
Line
Line
Programmed
Path
Tool Center
Path
Spiral
Arc
r
Spiral
Arc
Programmed
Path
Tool Center
Path
Arc
Arc
r
CC0
CC0
CC0CC0
Figure 47 Removing Compensation – Inside Corner
Outside Corner
If the last fully compensated move and the lead-out move form an outside corner, the last fully
compensated move ends at a point one cutter radius away from the intersection of the last fully
compensated move and the lead-out move, with the line from the programmed point to this compensated
point being perpendicular to the path of the fully compensated move at the intersection.
PMAC then adds a circular arc move with radius equal to the cutter radius, ending at a point one cutter
radius away from the same, with the line from the programmed point to this compensated endpoint being
perpendicular to the path of the lead-out move at the intersection.
Finally, PMAC gradually removes compensation over the lead-out move itself, ending at the programmed
endpoint of the lead-out move. When the lead-out move is a LINEAR-mode move, this compensated tool
path will be at a diagonal to the programmed move path. When the lead-in move is a CIRCLE-mode
move, this compensated tool path will be a spiral.