HEIDENHAIN TNC 426, User Manual

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HEIDENHAIN TNC 426, TNC 430 191
7.
5 Miscellaneous F
u
nctions f
o
r Rotary Ax
es
7.5 Miscellaneous Functions for
Rotary Axes
Feed rate in mm/min on rotary axes A, B, C:
M116
Standard behavior
The TNC interprets the programmed feed rate in a rotary axis in
degrees per minute. The contouring feed rate therefore depends on
the distance from the tool center to the center of the rotary axis.
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 in a rotary axis in mm/
min. With this miscellaneous function, the TNC calculates the feed
rate for each block at the start of the individual 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.
Shorter-path traverse of rotary axes: M126
Standard behavior
The standard behavior of the TNC while positioning rotary axes whose
display has been reduced to values less than 360° is dependent on
machine parameter 7682. In machine parameter 7682 is set whether
the TNC should consider the difference between nominal and actual
position, or whether the TNC should always (even without M126)
choose the shortest path traverse to the programmed position.
Examples:
The machine geometry must be entered in machine
parameters 7510 ff. by the machine tool builder.
Actual position Nominal position Traverse
350° 10° –340°
10° 340° +330°