HEIDENHAIN TNC 426B (280 472) ISO programming - Manual (Page 108)

92 5 Programming: Tools
Contouring with radius compensation: G41 and G42
G41
The tool moves to the left of the programmed contour
G42 The tool moves to the right of the programmed contour
The tool center moves along the contour at a distance equal to the
radius. “Right” or “left” are to be understood as based on the
direction of tool movement along the workpiece contour
Between two program blocks with different radius
compensations (G41 and G42) you must program at least
one block without radius compensation (that is, with
G40).
Radius compensation does not come into effect until the
end of the block in which it is first programmed.
You can also activate the radius compensation for
secondary axes in the working plane. Program the
secondary axes too in each following block, since
otherwise the TNC will execute the radius compensation
in the principal axis again.
Whenever radius compensation is activated with G41/
G42 or canceled with G40, the TNC positions the tool
perpendicular to the programmed starting or end
position. Position the tool at a sufficient distance from
the first or last contour point to prevent the possibility of
damaging the contour.
Entering radius compensation
Radius compensation is entered in a G01 block:
<
41 To select tool movement to the left of the
contour, select function G41, or
42 To select tool movement to the right of the
contour, select function G42, or
40 To select tool movement without radius
compensation or to cancel radius
compensation, select function G40.
To terminate the block, press the END key.
5.3 T
ool Compensation
X
Y
G41
X
Y
G42
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