HEIDENHAIN TNC 320 (340 551-01) - Manual (Page 268)

268 8 Programming: Cycles
8.6 Cy
cles f
o
r Multipass Milling
8.6 Cycles for Multipass Milling
Overview
The TNC offers four cycles for machining surfaces with the following
characteristics:
„ Flat, rectangular surfaces
„ Flat, oblique-angled surfaces
„ Surfaces that are inclined in any way
„
Twisted surfaces
MULTIPASS MILLING (Cycle 230)
1 From the current position in the working plane, the TNC positions
the tool at 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 at FMAX in the tool axis to the 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 at 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 at FMAX to the set-up
clearance.
Cycle Soft key
230 MULTIPASS MILLING
For flat rectangular surfaces
231 RULED SURFACE
For oblique, inclined or twisted surfaces
232 FACE MILLING
For level rectangular surfaces, with indicated oversizes
and multiple infeeds
X
Y
Z
1 1
1 2
Before programming, note the following:
From the current position, the TNC positions the tool at
the starting point, first in the working plane and then in the
spindle axis.
Pre-position the tool in such a way that no collision
between tool and clamping devices can occur.