HEIDENHAIN iTNC 530 (34049x-08) Cycle programming - Manual (Page 146)

146 Fixed cycles: pocket milling / stud milling / slot milling
5.2 RECT
ANGULAR POCKET (Cy
cle
251, DIN/ISO:
G251)
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 to the starting
position with radius compensation R0. Note parameter
Q367 (pocket position).
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).
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program DEPTH
= 0, the cycle will not be executed.
At the end of the cycle, the TNC returns the tool to the
starting position.
At the end of a roughing operation, the TNC positions the
tool back to the pocket center at rapid traverse. The tool is
above the current pecking depth by the set-up clearance.
Enter the set-up clearance so that the tool cannot jam
because of chips.
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 in the center of
the pocket at rapid traverse to the first plunging depth.