HEIDENHAIN TNC 320 User Manual page 76

Please note while programming:
Machine and TNC must be specially prepared by the
machine tool builder for use of this cycle.
This cycle is effective only for machines with servo-
controlled spindle.
Special boring bars for upward cutting are required for this
cycle.
Program a positioning block for the starting point (hole
center) in the working plane with radius compensation R0.
The algebraic sign for the cycle parameter depth
determines the working direction. Note: A positive sign
bores in the direction of the positive spindle axis.
The entered tool length is the total length to the underside
of the boring bar and not just to the tooth.
When calculating the starting point for boring, the TNC
considers the tooth length of the boring bar and the
thickness of the material.
Danger of collision!
Check the position of the tool tip when you program a
spindle orientation to the angle that you enter in Q336 (for
example, in the Positioning with Manual Data Input mode
of operation). Set the angle so that the tool tip is parallel to
a coordinate axis. Select a disengaging direction in which
the tool moves away from the edge of the hole.
76 Fixed Cycles: Drilling