HEIDENHAIN TNC 320 User Manual page 68

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.
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. If you program
DEPTH=0, the cycle will not be executed.
After the cycle is completed, the TNC restores the coolant
and spindle conditions that were active before the cycle
call.
Danger of collision!
Use the machine parameter displayDepthErr to define
whether, if a positive depth is entered, the TNC should
output an error message (on) or not (off).
Keep in mind that the TNC reverses the calculation for pre-
positioning when a positive depth is entered. This
means that the tool moves at rapid traverse in the tool axis
to set-up clearance below the workpiece surface!
Select a disengaging direction in which the tool moves
away from the edge of the hole.
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.
During retraction the TNC automatically takes an active
rotation of the coordinate system into account.
68 Fixed Cycles: Drilling