Siemens SINUMERIK 840D sl Function Manual page 146

W1: Tool offset
2.9 Modification of the offset data for rotatable tools
tool carrier is no longer treated separately because it must be assumed that this frame
component is already included in the complete frame (system frame PAROT).
When orientation transformation is active, bit 17 of machine data MD20360
$MC_TOOL_PARAMETER_DEF_MASK can be used, should the cutting edge no longer be in
the active machining plane, either to project the cutting edge into the machine plane (bit 17 = 0)
or alternatively to rotate the cutting edge into the machining plane (bit 17 = 1) in order to
calculate the modified cutting data.
Note
MD20360, bit 17
If this bit is set, it is the responsibility of the user to ensure, using an additional frame or by
changing the orientation, to ensure that the geometric conditions during machining match those
that exist during calculation.
If bit 20 of machine data MD20360 $MC_TOOL_PARAMETER_DEF_MASK is set to value "0",
standard values that deviate from zero can be used to calculate the modified cutting edge
position and the modified cutting direction for when the cutting edge parameters for the holder
angle and cutting direction ($TC_DP10 or $TC_DP24) have value 0. The following rules apply:
● A holder angle of 0° has the same effect as an angle of 112.5° on cutting edge positions 1
to 4.
● A holder angle of 0° has the same effect as an angle of 67.5° on cutting edge positions 5 to
8.
● A clearance angle of 0° has the same effect as an angle of 22.5° on cutting edge positions
1 to 4.
● A clearance angle of 0° has the same effect as an angle of 67.5° on cutting edge positions
5 to 8.
The holder angle and clearance angle might only be temporarily mapped onto the standard
values specified above to be able to calculate the modified cutting edge position and modified
cutting direction. I.e., reading system variables $TC_DP10 or $TC_DP24 still returns value "0".
If the tool rotates in the plane (rotation around an axis vertical to the machining place or around
the Y axis for G18), the cutting edge position is determined from the resulting angle for the
clearance and holder angles. If these two angles are not specified for the tool (i.e. $TC_DP10
and $TC_DP24 are both zero), the new cutting edge position is determined just from the turning
angle. A special feature here is that the cutting edge position only changes in steps of 90°. I.e.
the cutting edge position remains independent of the initial state either in the value range 1 to
4 or 5 to 8. The new cutting edge position is then determined exclusively from the angle of
rotation if the specified values for holder angle and clearance angle are impermissible (negative
values, resulting tool insert angle negative or greater than 90°). Impermissible angles can be
set to output an alarm (see MD20125 $MC_CUTMOD_ERR (Page 150)). Clearance angle and
holder angle are not modified in all these cases.
Depending on the rotation, the cut direction is modified in such a way that the resulting
clearance angle remains less than 90°. If the original cut direction and the original cutting edge
position do not match, then the cut direction is not modified during rotation of the tool. This
situation can be set to output an alarm (see MD20125 $MC_CUTMOD_ERR).
The angle of rotation in the plane, as it was determined from the tool carrier with orientation
capability or from the active kinematic transformation, is provided in the OPI variables
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Function Manual, 06/2019, A5E47435126B AA
Tools