Siemens SINUMERIK 840D Operating Manual page 339

Programming of arbitrary contours
The machining of arbitrary open or closed contours is generally programmed as follows:
1. Enter contour
2. Contour call (CYCLE62)
3. Path milling (roughing)
4. Path milling (finishing)
5. Path milling (chamfering)
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.
Milling
Operating Manual, 03/2010, 6FC5398-7CP20-1BA0
You build up the contour gradually from a series of different contour elements.
You select the contour to be machined.
The contour is machined taking into account various approach and retract strategies.
If you programmed a finishing allowance for roughing, the contour is machined again.
If you have planned edge breaking, chamfer the workpiece with a special tool.
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.
Programming technological functions (cycles)
8.3 Contour milling
339