Siemens sinumerik 840D sl Operating Manual page 392

Programming technology functions (cycles)
8.5 Contour milling
Path milling on right or left of the contour
A programmed contour can be machined with the cutter radius compensation to the right or
left. You can also select various modes and strategies of approach and retraction from the
contour.
Approach/retraction mode
The tool can approach or retract from the contour along a quadrant, semi-circle or straight
line.
● With a quadrant or semi-circle, you must specify the radius of the cutter center point path.
● With a straight line, you must specify the distance between the cutter outer edge and the
You can also program a mixture of modes, e.g. approach along quadrant, retract along semi-
circle.
Approach/retraction strategy
You can choose between planar approach/retraction and spatial approach/retraction:
● Planar approach:
● Spatial approach:
● Retraction is performed in reverse order.
Path milling along center-point path.
A programmed contour can also be machined along the center-point path if the radius
correction was switched-out. In this case, approaching and retraction is only possible along a
straight line or vertical. Vertical approach/retraction can be used for closed contours, for
example.
Machining type
You can select the machining mode (roughing, finishing, or chamfer) for path milling. If you
want to "rough" and then "finish", you have to call the machining cycle twice (Block 1 =
roughing, Block 2 = finishing). The programmed parameters are retained when the cycle is
called for the second time.
It is also possible to choose between machining the contour with a cutter radius offset or
traversing on the center-point path.
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contour starting or end point.
Approach is first at depth and then in the machining plane.
Approach is at depth and in machining plane simultaneously.
Mixed programming is possible, for example, approach in the machining plane, retract
spatially.
Operating Manual, 07/2010, 6FC5398-8CP40-0BA0
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