HEIDENHAIN TNC 620 User Manual page 377

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+ ...
HEIDENHAIN | TNC 620 | Conversational Programming User's Manual | 10/2015
Miscellaneous functions for path behavior 10.4
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