HEIDENHAIN TNC 370 - Pocket Milling

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Cycles
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8.3 Cycles for Milling Pockets, Studs and Slots
POCKET MILLING (Cycle 4)
* Program a pasitiantng block for rhs mming point (hole cenbd in the war&g plane with radius cwnpenserion RD.
* Progrm a positioning block for the starting point h the tool axis Qwtup cleewnce above workpiece surface),
* The algebfaic sign far cycfe parameter DEPTH de%ws the working direction.
l This cycle requires e center-cut end miff (IS0 I&M j, or a separate pifat drilling operation at the pocket csnbr.
l The radius af the packet c~rnaw is determined by the cutter radius. The toof does nat perform any circular
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Process
l The tool penetrates the workpiece at the starting position (pocket
center) and advances to the first infeed depth.
l The tool subsequently follows the programmed path at the specified
feed rate (see Fig. 8.9). The cutter begins milling in the positive axis
direction of the longer side. With square pockets, the cutter begins in
the positive Y direction.
l This process is repeated until the programmed depth is reached.
l At the end of the cycle the tool returns to the starting position.
Input data
l SET-UP CLEARANCE @ (incremental value):
Distance between tool tip (starting position) and workpiece surface.
l MILLING DEPTH @: (incremental value):
Distance between workpiece surface and bottom of hole.
l PECKING DEPTH 0: (incremental value):
lnfeed per cut. The TNC moves in one operation to the
DEPTH if:
- PECKING DEPTH and DEPTH are identical
- the PECKING DEPTH is greater than the DEPTH.
Enter a positive value.
l FEED RATE FOR PECKING:
Traversing speed of the tool during penetration.
l FIRST SIDE LENGTH @:
Length of the pocket, parallel to the first main axis of the working
plane.
l SECOND SIDE LENGTH @ :
Width of the pocket
The signs of the side lengths are always positive
l FEEDRATEF:
Traversing speed of the tool in the working plane
l ROTATION CLOCKWISE: DR- ?:
DR + : Climb milling with M3
DR - :
Up-cut milling with M3
Calculations:
Stepover factor k:
k = KxR
K:
Overlap factor (defined in MP7430, see page 12-8).)
R: Cutter radius
Fig. 8.9:
Tool path for roughing-out
Fig. 8.10: lnfeeds and distances for the
POCKET MILLING cycle
Fig. 8.11: Side lengths of the pocket
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TNC 370 8-17
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