8
Cycles
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8.7 Cycles for Coordinate Transformations
DATUM SHIFT (Cycle 7)
Application
With the aid of a datum shift, machining operations can be repeated at
various locations on the workpiece. If the datum shift is referenced to
the machine datum, you can clamp as many workpieces as desired on
the machine table, calculate the distance from the machine datum to the
datum of each workpiece and enter these values directly into the part
program with cycle 7.
Activation
When the DATUM SHIFT cycle has been defined, all coordinate data are
based on the new datum. Shifted axes are identified in the status.
input data
Only the coordinates of the new datum need to be entered. Absolute
values are based on the workpiece datum. If the coordinates of the new
datum are to be referenced to the machine datum, press the REF soft
key on the second soft-key row at the beginning of the cycle definition.
The TNC then identifies the first block of the cycle with REF.
Incremental values are based on the last valid datum: this datum can
itself be shifted
Fig. 8.69: Datum shift, absolute
Cancellation
To cancel a datum shift, enter the datum shift coordinates X = 0, Y = 0
and Z = 0.
Fig. 8.68: Activation of the datum shift
Fig. 8.70: Datum shift, incremental
@
When combining transformations, program the
&rum shift
first.
TNC 370
8-61