HEIDENHAIN TNC 426, User Manual

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312 8 Programming: Cycles
8.7 Cy
cles f
o
r multipass milling
MULTIPASS MILLING (Cycle 230)
1 From the current position in the working plane, the TNC positions
the tool in rapid traverse FMAX to the starting point
1 ; the TNC
moves the tool by its radius to the left and upward.
2 The tool then moves in FMAX in the tool axis to set-up clearance.
From there it approaches the programmed starting position in the
tool axis at the feed rate for plunging.
3 The tool then moves as the programmed feed rate for milling to
the end point
2 . The TNC calculates the end point from the
programmed starting point, the program length, and the tool
radius.
4 The TNC offsets the tool to the starting point in the next pass at
the stepover feed rate. The offset is calculated from the
programmed width and the number of cuts.
5 The tool then returns in the negative direction of the first axis.
6 Multipass milling is repeated until the programmed surface has
been completed.
7 At the end of the cycle, the tool is retracted in FMAX to set-up
clearance.
X
Y
Z
11
12
Before programming, note the following:
From the current position, the TNC positions the tool at
the starting point 1, first in the working plane and then in
the tool axis.
Pre-position the tool in such a way that no collision
between tool and clamping devices can occur.