HEIDENHAIN TNC 640 (34059x-02) - Manual (Page 354)

Programming: Miscellaneous functions
10.4 Miscellaneous functions for path behavior
10
354
TNC 640 | User's Manual
HEIDENHAIN Conversational Programming | 5/2013
Machining open contour corners: M98
Standard behavior
The TNC calculates the intersections of the cutter paths at inside
corners and moves the tool in the new direction at those points.
If the contour is open at the corners, however, this will result in
incomplete machining.
Behavior with M98
With the miscellaneous function M98, the TNC temporarily
suspends radius compensation to ensure that both corners are
completely machined:
Effect
M98 is effective only in the blocks in which it is programmed.
M98 takes effect at the end of block.
Example NC blocks
Move to the contour points 10, 11 and 12 in succession:
10 L X... Y... RL F
11 L X... IY... M98
12 L IX+ ...