HEIDENHAIN TNC 410 ISO Programming - Manual (Page 223)

HEIDENHAIN TNC 410, TNC 426, TNC 430 197
8.3 Cy
cles f
o
r Dr
illing
, T
a
p
p
ing
and
Th
read Millin
g BORE MILLING (Cycle G208, not TNC 410)
1 The TNC positions the tool in the tool axis at rapid traverse to the
programmed set-up clearance above the workpiece surface and
then moves the tool to the bore hole circumference on a rounded
arc (if enough space is available).
2 The tool mills in a helix from the current position to the first
plunging depth at the programmed feed rate.
3 When the drilling depth is reached, the TNC once again traverses
a full circle to remove the material remaining after the initial
plunge.
4 The TNC then positions the tool at the center of the hole again.
5 Finally the TNC returns to the setup clearance in rapid traverse. If
you have entered a 2nd set-up clearance, the tool subsequently
moves to that position in rapid traverse.
Before programming, note the following:
Program a positioning block for the starting point (hole
center) in the working plane with radius compensation
G40.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program DEPTH
= 0, the cycle will not be executed.
If you have entered the bore hole diameter to be the same
as the tool diameter, the TNC will bore directly to the
entered depth without any helical interpolation.