2. MACHINING DEFINITION
C–AXIS FAPT FUNCTION
Offset in FAPT/left–hand side as viewed in the direction in which the
tool moves (CP = 1)
1) An undefined input for the approach method or retraction method is
not accepted. An undefined input of the DT or DN value is not
2) If this function is added, approach for notching is always made from
the end face (Z plane). The approach point is obtained by adding a
clearance to the notching start point.
3) If finishing is executed after roughing, the tool is retracted by an
amount equal to the clearance along the Z–axis once roughing has been
completed. Then, finishing is started.
4) If cutter compensation is performed by the NC (bit 0 of MTF 1305 is
set to 1) and if approach or retraction along a tangent line or circle is
specified, linear movement along the tangent is inserted when cutter
compensation is started (G41/G42 is output) and ended (G40 is
output). The extension amount set in system parameter 371 is
referenced when the movement is inserted.
New system parameter
No. Format Initial value Description
Extension for approach or retraction
along a tangent line or circle during
371 Real number
C–axis notching or Y–axis contouring
Unit: mm or inch
*) The parameter affects the Family Program. Always specify a
positive value for this parameter.
The cutter compensation performed by the NC instigates the following
operation, depending on the approach/retraction method:
D Direct approach/retraction
The NC does not perform cutter compensation. If an attempt is
made to define 1 (direct) as the approach method (SM) or retraction
method (EM) after bit 0 of MTF 1305 has been set to 1, the
“CORRECT KEYIN” error message is displayed. The attempted
input is not accepted.
If bit 0 of MTF 1305 is set to 1 after direct approach/retraction has
been defined, an error occurs when an attempt is made to create the
NC data. The NC data cannot be created.