Tapping With A Floating Tap Holder (Cycle 2) - HEIDENHAIN TNC 426 B User Manual

TAPPING with a floating tap holder (Cycle 2)

1 The tool drills to the total hole depth in one movement
2 Once the tool has reached the total hole depth, the direction of
spindle rotation is reversed and the tool is retracted to the
starting position at the end of the DWELL TIME.
3 At the starting position, the direction of spindle rotation reverses
once again.
Before programming, note the following:
Program a positioning block for the starting point (hole
center) in the working plane with RADIUS
COMPENSATION R0.
Program a positioning block for the starting point in the
tool axis (set-up clearance above the workpiece surface).
The algebraic sign for the depth parameter determines
the working direction.
A floating tap holder is required for tapping. It must
compensate the tolerances between feed rate and
spindle speed during the tapping process.
When a cycle is being run, the spindle speed override
knob is disabled. The feed rate override knob is active
only within a limited range, which is defined by the
machine tool builder (refer to your machine manual).
For tapping right-hand threads activate the spindle with
M3, for left-hand threads use M4.
Setup clearance
between tool tip (at starting position) and workpiece
surface. Standard value: approx. 4 times the thread
pitch
Total hole depth
Distance between workpiece surface and end of
thread
Dwell time in seconds: Enter a value between 0 and
0.5 seconds to avoid wedging of the tool during
retraction.
Feed rate F: Traversing speed of the tool during
tapping
The feed rate is calculated as follows: F = S x p,
where
F is the feed rate in mm/min),
S is the spindle speed in rpm,
and p is the thread pitch in mm
Retracting after a program interruption
If you interrupt program run during tapping with the machine stop
button, the TNC will display a soft key with which you can retract the
tool.
HEIDENHAIN TNC 426 B, TNC 430
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(incremental value): Distance
(thread length, incremental value):
Z
Example NC blocks:
13 Y L DEF 2.0 TAPPING
14 Y L DEF 2.1 SET UP
15 Y L DEF 2.2 DEPTH -20
16 Y L DEF 2.3 DWELL 0
17 Y L DEF 2.4 F100
X
2
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