Siemens SINUMERIK 840D sl Function Manual page 148

W1: Tool offset
2.9 Modification of the offset data for rotatable tools
S:
P:
SL:
①
②
③
Figure 2-43
Note
As the cutting edge reference point is defined by the tool length vector, modifying the cutting
edge reference point changes the effective tool length.
Tool rotation
The rotation of the tool tip and the tool adapter is described by tool parameter $TC_DPROT.
This parameter (angle) is only practical for tools that do not rotate symmetrically (e.g. turning
tools, boring bars). Rotation is performed around the direction that is defined by the vector
product of tool normal vector and tool orientation vector. For an active tool, this vector can be
read with system variable $P_TOOLBIN. For standard turning tools, this vector points toward
the Z axis for G18. I.e. it turns around the axis around which angle γ also turns.
148
Cutting edge center point
Cutting edge reference point
Cutting edge position
Tool with cutting edge position 3, clearance angle 22.5°, and holder angle 112.5°
For rotations of the tool up to 22.5°, the cutting edge position is maintained, the position of the
cutting edge reference point relative to the tool however, is compensated in such a way that the
relative position of both points is maintained in the machining plane.
For bigger tool rotations (up to 67.5°), the cutting edge position changes to value 8.
Cutting edge reference point and cutting edge position for tool rotation
Function Manual, 06/2019, A5E47435126B AA
Tools