Siemens SINUMERIK 840D sl Operating Manual page 224

Programming a cycle
4.7 Milling
Approach/retraction during helical machining
In helical machining, the material is removed down to pocket depth in a helical movement.
1. The tool approaches the center point of the pocket at rapid traverse at the height of the
2. Infeed to the first machining diameter.
3. The circular pocket is machined to pocket depth using the selected machining method.
4. The tool moves back to the safety distance at rapid traverse.
Machining method for plane-by-plane retraction
For milling the circular pocket, you can select any of the following machining methods for
plane-by-plane retraction:
● Roughing
● Finishing
● Edge finishing
● Chamfering
Machining method for helical retraction
For milling the circular pocket, you can select any of the following machining methods for
helical retraction:
● Roughing
● Finishing
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retraction plane and adjusts to the safety distance.
Roughing involves machining the individual planes of the circular pocket one after the
other from the center out, until depth Z1 or X1 is reached.
During finishing, the edge is always machined first. The pocket edge is approached on
the quadrant that joins the pocket radius. During the last infeed, the base is finished from
the center out.
Edge finishing is performed in the same way as finishing, except that the last infeed (base
finishing) is omitted.
Chamfering involves edge breaking at the upper edge of the circular pocket.
During roughing, the circular pocket is machined downward with helical movements.
A full circle is made at pocket depth to remove the residual material.
The tool is removed from the edge and base in the quadrant and retracted with rapid
traverse to the safety distance.
This process is repeated layer by layer, from inside out, until the circular pocket has been
completely machined.
During finishing, machining begins at the edge and continues in a helical movement until
the bottom is reached.
A full circle is made at pocket depth to remove the residual material.
Operating Manual, 01/2008, 6FC5398-7AP10-0BA0
HMI sl Turning