3 miscellaneous functions for rotary axes – HEIDENHAIN TNC 320 (340 55x-04) ISO programming User Manual
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Programming: Multiple Axis Machining
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1
.3 Miscellaneous F
unctions f
o
r Rotary Ax
es
11.3 Miscellaneous Functions for
Rotary Axes
Feed rate in mm/min on rotary axes A, B, C: 
M116 (software option 1)
Standard behavior
The TNC interprets the programmed feed rate of a rotary axis in 
degrees/min (in mm programs and also in inch programs). The feed 
rate therefore depends on the distance from the tool center to the 
center of axis rotation.
The larger this distance becomes, the greater the contouring feed 
rate.
Feed rate in mm/min on rotary axes with M116
The TNC interprets the programmed feed rate of a rotary axis in 
degrees/min (or 1/10 inch/min). In this case, the TNC calculates the 
feed for the block at the start of each block. With a rotary axis, the feed 
rate is not changed during execution of the block even if the tool 
moves toward the center of the rotary axis.
Effect
M116 is effective in the working plane. With M117 you can reset 
M116. M116 is also canceled at the end of the program.
M116 becomes effective at the start of block.
The machine geometry must be specified by the machine 
tool builder in the description of kinematics.
M116 works only on rotary tables. M116 cannot be used 
with swivel heads. If your machine is equipped with a 
table/head combination, the TNC ignores the swivel-head 
rotary axes.
M116 is also effective in an active tilted working plane.
