Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
302
Writing and Executing Motion Programs
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.
Turbo 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, Turbo 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.
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.
Turbo 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, Turbo 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.
Line to Line
Line to Arc
Arc to Arc
Arc to Line
Removing Compensation – Outside Corner
Line
Line
Programmed
Path
Tool Center
Path
Line
Line
Arc
r
r
Spiral
Arc
Programmed
Path
Tool Center
Path
Arc
Arc
r
r
Line
Line
Programmed
Path
Tool Center
Path
Spiral
Arc
r
r
Line
Line
Programmed
Path
Tool Center
Path
Arc
Arc
r
r
Arc
Arc
CC0
CC0
CC0
CC0
Note that this behavior is different from changing the magnitude of the compensation radius to zero while
leaving compensation active. An arc move is always added at the corner, regardless of the setting of
Isx99. This ensures that the lead-out move will never cut into the last fully compensated move.
leaving compensation active. An arc move is always added at the corner, regardless of the setting of
Isx99. This ensures that the lead-out move will never cut into the last fully compensated move.
Failures in Cutter Compensation
It is possible to give Turbo PMAC a program sequence in which the cutter compensation algorithm will
fail, not producing desired results. There are three types of reasons the compensation can fail:
1. Inability to calculate through corner
2. Inside corner smaller than radius
3. Inside arc radius smaller than cutter radius
fail, not producing desired results. There are three types of reasons the compensation can fail:
1. Inability to calculate through corner
2. Inside corner smaller than radius
3. Inside arc radius smaller than cutter radius
Inability to Calculate through Corner
First, if Turbo PMAC cannot see ahead far enough in the program to find the next move with a
component in the plane of compensation before the present move is calculated, then it will not be able to
compute the intersection point between the two moves. This can happen for several reasons:
component in the plane of compensation before the present move is calculated, then it will not be able to
compute the intersection point between the two moves. This can happen for several reasons:
•
There is a move with no component in the plane of compensation (i.e. perpendicular to the plane of
compensation, as in a Z-axis-only move during XY compensation) before the next move in the plane
of compensation, and no CCBUFFER compensation block buffer declared (see below).
compensation, as in a Z-axis-only move during XY compensation) before the next move in the plane
of compensation, and no CCBUFFER compensation block buffer declared (see below).
•
There are more moves with no component in the plane of compensation before the next move in the
plane of compensation than the CCBUFFER compensation block buffer can hold (see below).
plane of compensation than the CCBUFFER compensation block buffer can hold (see below).
•
There are more than 10 DWELLs before the next move in the plane of compensation.