Siemens SINUMERIK 808D User Manual page 202

The tool is fed to the safety clearance (SDIS) at rapid traverse with subsequent traversing to the machining depth at
feedrate. To approach the spigot contour, the tool travels along a semi-circular path.
The milling direction can be determined either as up-cut milling or down-cut milling with reference to the spindle direction.
If the spigot is bypassed once, the contour is left along a semi-circle in the plane, and the tool is fed to the next machining
depth.
The contour is then reapproached along a semi-circle and the spigot traversed once. This process is repeated until the
programmed spigot depth is reached. Then, the retraction plane (RTP) is approached at rapid traverse rate.
● Depth infeed:
– Feeding to the safety clearance
– Insertion to machining depth
The first machining depth is calculated from the total depth, finishing allowance, and the maximum possible depth infeed.
Se quence of motions when finishing (VARI=2):
Depending on the set parameters FAL and FALD, finishing is either carried out at the surface contour or at the base or both
together. The approach strategy corresponds to the motions in the plane as with roughing.
Explanation of the parameters
For an explanation of the parameters RTP, RFP, SDIS, DP, and DPR, see Section "Drilling, centering - CYCLE81
(Page 157)".
For an explanation of the parameters MID, FAL, FALD, FFP1, and FFD, see Section "Milling a rectangular pocket -
POCKET3 (Page 221)".
L ENG, WID and CRAD (spigot length, spigot width and corner radius)
Use the parameters LENG, WID and CRAD to define the form of a slot in the plane.
The spigot is always dimensioned from the center. The length (LENG) always refers to the abscissa (with a plane angle of 0
degrees).
PA, PO (reference point)
Use the parameters PA and PO to define the reference point of the spigot along the abscissa and the ordinate.
This is the spigot center point.
STA (angle)
STA specifies the angle between the first axis of the plane (abscissa) and the longitudinal axis of the spigot.
C D IR (milling direction)
Use this parameter to specify the machining direction for the spigot.
202
Programming and Operating Manual (Milling)
6FC5398-4DP10-0BA6, 09/2017