
B-63944EN-1/02 PROGRAMMING 5.COMPENSATION FUNCTION
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5.5 VECTOR RETENTION (G38)
In cutter or tool nose radius compensation, by specifying G38 in offset
mode, it is possible to retain the compensation vector at the end
position of the previous block, without performing intersection
calculation.
Format
(In offset mode)
G38 IP_ ;
IP :Value specified for axial movement
Explanation
- Vector retention
By specifying the above command, a vector is created at the end point
of the block immediately preceding the G38 block, vertical to that
block. In the G38 block, the vertical vector output in the previous
block is retained. G38 is a one-shot G code. With the next move
command without a G38 command, the compensation vector is
re-created.
Limitation
- Mode
Specify G38 in either G00 or G01 mode. If it is specified in G02 or
G03 (circular interpolation) mode, a radial error may occur at the start
and end points.
Example
X axis
Z axis
(10.0, 0.0)
(15.0, 5.0)
Block N1
Offset vector
Block N2
Block N3
Program command
Tool nose radius
center path
:
: (In offset mode)
N1 G38 X0.0 Z10.0 ;
N2 G38 X5.0 Z15.0 ;
N3 G38 X0.0 Z10.0 ;
N4 Z20.0 ;
:
: