HEIDENHAIN TNC 426 (280 476) - Manual (Page 208)

HEIDENHAIN TNC 426, TNC 430 181
7.
4 Miscellaneous F
unctions f
o
r Cont
our
ing Beha
vior
7.4 Miscellaneous Functions for
Contouring Behavior
Smoothing corners: M90
Standard behavior
The TNC stops the tool briefly in positioning blocks without tool radius
compensation. This is called an accurate stop.
In program blocks with radius compensation (RR/RL), the TNC
automatically inserts a transition arc at outside corners.
Behavior with M90
The tool moves at corners with constant speed: This provides a
smoother, more continuous surface. Machining time is also reduced.
See figure at center right.
Example application: Surface consisting of a series of straight line
segments.
Effect
M90 is effective only in the blocks in which it is programmed with
M90.
M90 becomes effective at the start of block. Operation with servo lag
must be active.
X
Y
X
Y