HEIDENHAIN TNC 426 B User Manual page 177

Set-up clearance Q200 (incremental value): Distance
between tool tip and workpiece surface.
Depth of counterbore Q249 (incremental value):
Distance between underside of workpiece and the
top of the hole. A positive sign means the hole will be
bored in the positive spindle axis direction.
Material thickness Q250 (incremental value): Thickness
of the workpiece
Off-center distance Q251 (incremental value): Off-
center distance for the boring bar; value from tool data
sheet
Tool edge height Q252 (incremental value): Distance
between the underside of the boring bar and the main
cutting tooth; value from tool data sheet
Feed rate for pre-positioning Q253: Traversing speed
of the tool when moving in and out of the workpiece,
in mm/min
Feed rate for counterboring Q254: Traversing speed of
the tool during counterboring in mm/min
Dwell time Q255: Dwell time in seconds at the top of
the bore hole
Workpiece surface coordinate Q203 (absolute value):
Coordinate of the workpiece surface
2nd set-up clearance Q204 (incremental value):
Coordinate in the tool axis at which no collision
between tool and workpiece (clamping devices) can
occur.
Disengaging direction (0/1/2/3/4) Q214: Determine the
direction in which the TNC displaces the tool by the
off-center distance (after spindle orientation).
1: Displace tool in the negative main axis direction
2: Displace tool in the negative secondary axis direction
3: Displace tool in the positive main axis direction
4: Displace tool in the positive secondary axis direction
Danger of collision!
Check the position of the tool tip when you program a
spindle orientation to 0° (for example, in the Positioning
with Manual Data Input mode of operation). Align the
tool tip so that it is parallel to a coordinate axis. Select a
disengaging direction in which the tool can plunge into
the hole without danger of collision.
162
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Z
Q200
Q250
Q249
Q200
Z
Q252
Q255
Q254
Q214
Example NC blocks:
11 Y L DEF 204 BA K BORING
Q200=2 ;SET-UP
Q249=+5 ;DEPTH OF
Q250=20 ;MATERIAL THI KNESS
Q251=3.5 ;OFF- ENTER DISTAN E
Q252=15 ;TOOL EDGE HEIGHT
Q253=750 ;F PRE-POSITIONING
Q254=200 ;F OUNTERBORING
Q255=0 ;DWELL TIME
Q203=+0 ;SURFA E
Q204=50 ;2. SET-UP
Q214=1 ;DISENGAGING DIRE TN
Q204
Q203
X
Q253
Q251
X
LEARAN E
OUNTERBORE
OORDINATE
LEARAN E
8 Programming: Cycles