HEIDENHAIN TNC 426B (280 472) ISO programming - Manual (Page 168)

8 Programming: Cycles 152
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 TOTAL HOLE
DEPTH determines the working direction.
ú Set-up clearance Q200 (incremental value): Distance
between tool tip and workpiece surface.
ú Depth Q201 (incremental value): Distance between
workpiece surface and bottom of hole (tip of drill
taper)
ú Feed rate for plunging Q206: Traversing speed of the
tool during drilling in mm/min
ú Plunging depth Q202 (incremental value):
Infeed per cut The TNC will go to depth in one
movement if:
■ The plunging depth is equal to the depth
■ The plunging depth is greater than the depth
The depth does not have to be a multiple of the
plunging depth.
ú Dwell time at top Q210: Time in seconds that the tool
remains at set-up clearance after having been
retracted from the hole for chip release.
ú Workpiece surface coordinate Q203 (absolute value):
Coordinate of the workpiece surface
ú 2nd set-up clearance Q204 (incremental value):
Coordinate in the tool axis at which no collision
between tool and workpiece (clamping devices) can
occur.
ú Decrement Q212 (incremental value): Value by which
the TNC decreases the plunging depth after each
infeed.
ú Nr of breaks before retracting Q213: Number of chip
breaks after which the TNC is to withdraw the tool
from the hole for chip release. For chip breaking, the
TNC retracts the tool each time by 0.2 mm.
ú Minimum plunging depth Q205 (incremental value): If
you have entered a decrement, the TNC limits the
plunging depth to the value entered with Q205.
ú Dwell time at depth Q211: Time in seconds that the
tool remains at the hole bottom
X
Z
Q200
Q201
Q206
Q202
Q210
Q203
Q204
Q211
Q208
8.3 Dr
illing Cy
cles
ú Retraction feed rate Q208: Traversing speed of
the tool in mm/min when retracting from the
hole. If you enter Q208 = 0, the tool retracts in
rapid traverse.
The TNC 426, TNC 430 with NC software 280
474-xx also provides:
ú Retraction rate for chip breaking Q256
(incremental): value by which the TNC retracts
the tool during chip breaking
Example NC block:
N10 G203 Q200=2 Q201=-20 Q206=150
Q202=5 Q210=0 Q203=+0 Q204=50
Q212=0.2 Q213=3 Q205=3 Q211=0.25
Q208=500*
Kkap8.pm6 29.06.2006, 08:06 152