HEIDENHAIN iTNC 530 (34049x-08) Cycle programming - Manual (Page 160)

160 Fixed cycles: pocket milling / stud milling / slot milling
5.5 CIR
C
ULAR SL
O
T
(Cy
cle 254, DIN/ISO:
G254)
Please note while programming:
With an inactive tool table you must always plunge
vertically (Q366=0) because you cannot define a plunging
angle.
Pre-position the tool in the machining plane with radius
compensation R0. Define parameter Q367 (reference for
slot position
) appropriately.
The TNC runs the cycle in the axes (machining plane) with
which you approached the starting position. For example,
in X and Y if you programmed CYCL CALL POS X... Y... or
in U and V if you programmed CYCL CALL POS U... V...
The TNC automatically pre-positions the tool in the tool
axis. Note parameter Q204 (2nd set-up clearance).
At the end of the cycle the TNC merely moves the tool in
working plane back to the center of the pitch circle; in the
other working plane axis the TNC does not do any
positioning. If you define a slot position not equal to 0,
then the TNC only positions the tool in the tool axis to the
2nd set-up clearance. Prior to a new cycle call, move the
tool back to the starting position or program always
absolute traverse motions after the cycle call.
At the end of the cycle the TNC returns the tool to the
starting point (center of the pitch circle) in the working
plane. Exception: if you define a slot position not equal to
0, then the TNC only positions the tool in the tool axis to
the 2nd set-up clearance. In these cases, always program
absolute traverse movements after the cycle call.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program DEPTH
= 0, the cycle will not be executed.
If the slot width is greater than twice the tool diameter, the
TNC roughs the slot correspondingly from inside out. You
can therefore mill any slots with small tools, too.
The slot position 0 is not allowed if you use Cycle 254
Circular Slot in combination with Cycle 221.
Danger of collision!
Enter in MP7441 bit 2 whether the TNC should output an
error message (bit 2=1) or not (bit 2=0) if a positive depth
is entered.
Keep in mind that the TNC reverses the calculation for pre-
positioning when a positive depth is entered. This
means that the tool moves at rapid traverse in the tool axis
to set-up clearance below the workpiece surface!
If you call the cycle with machining operation 2 (only
finishing), then the TNC positions the tool to the first
plunging depth at rapid traverse!