HEIDENHAIN TNC 320 (340 551-02) User Manual
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8 Programming: Cycles
8.3 Cy
cles f
o
r Milling P
o
c
k
ets, St
uds and Slots
SLOT (oblong hole) with reciprocating plunge-
cut (Cycle 210)
Roughing
1
At rapid traverse, the TNC positions the tool in the tool axis to the
2nd set-up clearance and subsequently to the center of the left
circle. From there, the TNC positions the tool to the set-up
clearance above the workpiece surface.
2
The tool moves at the feed rate for milling to the workpiece
surface. From there, the cutter advances in the longitudinal
direction of the slot—plunge-cutting obliquely into the material—
until it reaches the center of the right circle.
3
The tool then moves back to the center of the left circle, again with
oblique plunge-cutting. This process is repeated until the
programmed milling depth is reached.
4
For the purpose of face milling, the TNC moves the tool at the
milling depth to the other end of the slot and then back to the
center of the slot.
Finishing
5
The TNC positions the tool in the center of the left circle and then
moves it tangentially on a semicircle to the left end of the slot. The
tool subsequently climb mills the contour (with M3), and if so
entered, in more than one infeed.
6
When the tool reaches the end of the contour, it departs the
contour tangentially and returns to the center of the left circle.
7
At the end of the cycle, the tool is retracted at rapid traverse FMAX
to the set-up clearance and—if programmed—to the 2nd set-up
clearance.
Before programming, note the following:
The TNC automatically pre-positions the tool in the tool
axis and working plane.
During roughing the tool plunges into the material with a
sideward reciprocating motion from one end of the slot to
the other. Pilot drilling is therefore unnecessary.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program
DEPTH = 0, the cycle will not be executed.
The cutter diameter must not be larger than the slot width
and not smaller than a third of the slot width.
The cutter diameter must be smaller than half the slot
length. The TNC otherwise cannot execute this cycle.