HEIDENHAIN ITNC 530 User Manual page 450

Strategy Q389=2
3 The tool subsequently advances to the stopping point
rate for milling. The end point lies outside the surface. The control
calculates the end point from the programmed starting point, the
programmed length, the programmed safety clearance to the side
and the tool radius.
4 The TNC positions the tool in the spindle axis to the set-up
clearance over the current infeed depth, and then moves at the
pre-positioning feed rate directly back to the starting point in the
next line. The TNC calculates the offset from the programmed
width, the tool radius and the maximum path overlap factor.
5 The tool then returns to the current infeed depth and moves in the
direction of the next end point 2.
6 The multipass process is repeated until the programmed surface
has been completed. At the end of the last pass, the next
machining depth is plunged to.
7 In order to avoid non-productive motions, the surface is then
machined in reverse direction.
8 The process is repeated until all infeeds have been machined. In
the last infeed, simply the finishing allowance entered is milled at
the finishing feed rate.
9 At the end of the cycle, the tool is retracted at FMAX to the 2nd
set-up clearance.
Before programming, note the following:
Enter the 2nd set-up clearance in Q204 so that no collision
between tool and clamping devices can occur.
450
2 at the feed
8 Programming: Cycles