HEIDENHAIN TNC 320 (340 55x-04) Cycle programming - Manual (Page 128)

128 Fixed Cycles: Pocket Milling / Stud Milling / Slot Milling
5.2 RECT
ANGULAR POCKET (Cy
c
le 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 automatically pre-positions the tool in the tool
axis. Note Parameter Q204 (2nd setup 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 setup clearance.
Enter the setup clearance so that the tool cannot jam
because of chips.
Danger of collision!
Use the machine parameter displayDepthErr to define
whether, if a positive depth is entered, the TNC should
output an error message (on) or not (off).
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 setup 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.