HEIDENHAIN TNC 320 (340 551-01) - Manual (Page 232)

232 8 Programming: Cycles
8.3 Cy
cles f
o
r Milling P
o
c
k
ets, St
uds and Slots
CIRCULAR POCKET (Cycle 5)
Cycles 1, 2, 3, 4, 5, 17, 18 are in a group of cycles called special cycles.
Here in the second soft-key row, select the OLD CYCLS soft key.
1 The tool penetrates the workpiece at the starting position (pocket
center) and advances to the first plunging depth.
2 The tool subsequently follows a spiral path at the feed rate F - see
figure at right. For calculating the stepover factor k,
’FF˜‰ ˜
˜| ©4dF˜T}Š:˜z"VF˜¢¢–.
3 This process is repeated until the depth is reached.
4 At the end of the cycle, the TNC retracts the tool to the starting
position.
8 Set-up clearance 1 (incremental value): Distance
between tool tip (at starting position) and workpiece
surface.
8 Milling depth 2 : Distance between workpiece
surface and bottom of pocket.
8 Plunging depth 3 (incremental value): Infeed per cut
The TNC will go to depth in one movement if:
„ the plunging depth is equal to the depth
„ the plunging depth is greater than the depth
X
Y
X
Z
1 1
1 2
1 3
Before programming, note the following:
This cycle requires a center-cut end mill (ISO 1641), or pilot
drilling at the pocket center.
Pre-position over the pocket center with radius
compensation R0.
Program a positioning block for the starting point in the tool
axis (set-up clearance above the workpiece surface).
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program
DEPTH = 0, the cycle will not be executed.
Use the machine parameter suppressDepthErr to define
whether, if a positive depth is entered, the TNC should
output an error message (on) or not (off).
Danger of collision!