HEIDENHAIN TNC 640 (34059x-02) Cycle programming - Manual (Page 102)

Fixed Cycles: Tapping / Thread Milling
4.2 TAPPING NEW with a floating tap holder (Cycle 206, DIN/ISO:
G206)
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102
TNC 640 | User's Manual Cycle Programming | 5/2013
Please note while programming:
Program a positioning block for the starting point
(hole center) in the working plane with radius
compensation
R0.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program
DEPTH=0, the cycle will not be executed.
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.
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 set-up clearance below
the workpiece surface!