Siemens SINUMERIK 840D sl Turning Operating Manual page 293

The retraction for a cycle ends at the safety clearance. Only the subsequent cycle moves to the
retraction plane. This enables a special approach/retraction cycle to be used.
Note
When selecting the traversing paths, the tool tip is always taken into account; i.e. the tool
expansion is not considered. Therefore, you should ensure that the retraction planes are an
appropriate distance away from the workpiece.
Approach/retraction sequence in a machining cycle
Figure 9-5
● The tool traverses in rapid traverse along the shortest path from the tool change point to the
retraction plane, which runs parallel to the machining plane.
● After this, the tool traverses in rapid traverse to the safety clearance.
● Following this, the workpiece is then machined with the programmed machining feedrate.
● After machining, the tool retracts with rapid traverse to the safety clearance.
● The tool then continues to traverse vertically in rapid traverse to the retraction plane.
● From there, the tool traverses in rapid traverse along the shortest path to the tool change
point. If the tool does not need to be changed between two machining processes, the tool
traverses from the retraction plane to the next machining cycle.
The spindle (main, tool, or counter-spindle) begins to rotate immediately after the tool change.
You define the tool change point, the retraction plane, and the safety clearance in the program
header.
Turning
Operating Manual, 06/2019, A5E44903486B AB
Machining cycle, approach/retraction
Creating a ShopTurn program
9.4 Fundamentals
293