User's Manual ISO TNC 360 (260020xx, 280490xx) - heidenhain

5 Programming Tool Movements
5.6 M Functions for Contouring Behavior
Machining small contour steps: M97
TNC 360
Standard behavior – without M97
The TNC inserts a transition arc at outside corners.
At very short contour steps this would cause the
tool to damage the contour. In such cases the TNC
interrupts the program run and displays the error
message TOOL RADIUS TOO LARGE.
Machining contour steps – with M97
The TNC calculates the contour intersection S
(see figure) for the contour elements – as at inside
corners – and moves the tool over this point. M97
is programmed in the same block as the outside
corner point.
Duration of effect
The miscellaneous function M97 is effective only in
the blocks in which it is programmed.
.
.
.
N5 G99 L ... R+20 ................................................. Large tool radius
.
.
.
.
.
.
Y
Fig. 5.42: Standard behavior without M97 if the block were to be
executed as programmed
Y
13
14
S
Fig. 5.43: Contouring behavior with M97
A contour machined with M97 is less complete than one without. You may wish to rework the contour with a
smaller tool.
Program example
N20 G01 X ... Y ... M97 ........................................... Move to contour point 13
N30 G91 Y–0.5 ........................................................ Machine the small contour step 13-14
N40 X+100 .............................................................. Move to contour point 15
N50 Y+0.5 M97 ...................................................... Machine the small contour step 15-16
N60 G90 X ... Y ... ................................................... Move to contour point 17
The outer corners are programmed in blocks N20 and N50: these are the
blocks in which you program M97.
S
16
15
17
X
X
5-37