Siemens SINUMERIK 840D sl Programming Manual page 702

Work preparation
3.9 Transformations
①
②
Note
OFFN should be at least as large as the tool radius to avoid damage occurring to the opposite
side of the groove wall.
Note
OFFN acts differently with TRACYL than it does without TRACYL. Since, even without
TRACYL, OFFN is included when TRC is active, OFFN should be reset to zero after TRAFOOF.
NOTICE
Effect of OFFN depends on the transformation type
For TRACYL transformation 513 (TRACYL with groove side offset), half the groove width is
programmed for OFFN.
For TRACYL transformation 512 (TRACYL with groove side offset), the value of OFFN acts as
an allowance for the TRC.
Tool radius compensation (TRC)
For TRACYL transformation 513, the TRC is not taken into account relative to the groove side,
but to the programmed center of the groove. In order that the tool travels to the left of the groove
side, statement G42 must be programmed instead of G41 or the value of OFFN specified with
a negative sign.
Tool diameter
With TRACYL and a tool whose diameter is less than the groove width, the same groove side
geometry is not generated as with a tool whose diameter is the same as the groove width. To
improve the precision, it is recommended that the tool diameter is selected to be only slightly
less than the groove width.
702
OFFN
Programmed path
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming