HEIDENHAIN TNC 360 ISO Programming - Manual (Page 166)

8-13
8 Cycles
TNC 360
Fig. 8.10: Tool path for roughing out
Fig. 8.12: Direction of the cutter path
8.2 Simple Fixed Cycles
Fig. 8.11: Distances and infeeds with
CIRCULAR POCKET MILLING
A
B
C
G78 G77
F
R
CIRCULAR POCKET MILLING G77/G78
Process
• Circular pocket milling is a roughing cycle. The tool penetrates the
workpiece from the starting position (pocket center).
• The cutter then follows a spiral path at the programmed feed rate (see
Fig. 8.10). The stepover factor is determined by the value of k (see
POCKET MILLING cycle G75/G76: calculations).
• The process is repeated until the programmed milling depth is reached.
• At the end of the cycle the tool returns to the starting position.
Required tool
This cycle requires a center-cut end mill (ISO 1641) or a separate pilot
drilling operation at the pocket center.
Direction of rotation for roughing out
Clockwise direction of rotation G77
Counterclockwise direction of rotation G78
Input data
• SETUP CLEARANCE
A
• MILLING DEPTH
B
: DEPTH of the pocket
• PECKING DEPTH
C
• FEED RATE FOR PECKING:
Traversing speed of the tool during penetration.
• CIRCLE RADIUS R :
Radius of the circular pocket.
• FEED RATE:
Traversing speed of the tool in the working plane.