Feed rate for circular arcs: m109/m110/m111 – HEIDENHAIN TNC 320 (340 55x-05) ISO programming User Manual
Page 279

HEIDENHAIN TNC 320
279
9.4 Miscellaneous F
unctions f
o
r Cont
our
ing Beha
vior
Feed rate in millimeters per spindle revolution: 
M136
Standard behavior
The TNC moves the tool at the programmed feed rate F in mm/min.
Behavior with M136
With M136, the TNC does not move the tool in mm/min, but rather at 
the programmed feed rate F in millimeters per spindle revolution. If 
you change the spindle speed by using the spindle override, the TNC 
changes the feed rate accordingly.
Effect
M136 becomes effective at the start of block.
You can cancel M136 by programming M137.
Feed rate for circular arcs: M109/M110/M111
Standard behavior
The TNC applies the programmed feed rate to the path of the tool 
center.
Behavior at circular arcs with M109
The TNC adjusts the feed rate for circular arcs at inside and outside 
contours so that the feed rate at the tool cutting edge remains 
constant.
Behavior at circular arcs with M110
The TNC keeps the feed rate constant for circular arcs at inside 
contours only. At outside contours, the feed rate is not adjusted.
Effect
M109 and M110 become effective at the start of block. To cancel 
M109 or M110, enter M111.
In inch-programs, M136 is not permitted in combination 
with the new alternate feed rate FU.
The spindle is not permitted to be controlled when M136 
is active.
If you define M109 or M110 before calling a machining 
cycle with a number greater than 200, the adjusted feed 
rate is also effective for circular arcs within these 
machining cycles. The initial state is restored after 
finishing or aborting a machining cycle.
