HEIDENHAIN TNC 426B (280 472) ISO programming - Manual (Page 179)

163 HEIDENHAIN TNC 410, TNC 426, TNC 430
RIGID TAPPING NEW
(Cycle G207, only with the TNC 426, TNC 430 with
NC software 280 474-xx)
Machine and control must be specially prepared by the
machine tool builder to enable rigid tapping.
The TNC cuts the thread without a floating tap holder in one or
more passes.
The advantages of rigid tapping over tapping with a floating tap
holder are described under Cycle 85.
1 The TNC positions the tool in the tool axis at rapid traverse FMAX
to the programmed set-up clearance above the workpiece
surface.
2 The tool drills to the total hole depth in one movement
3 Once the tool has reached the total hole depth, the direction of
spindle rotation is reversed and the tool is retracted to the set-up
clearance at the end of the DWELL TIME. If you have entered a
2nd set-up clearance, the tool subsequently moves to that
position in FMAX.
4 The TNC stops the spindle turning at set-up clearance
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 parameter total hole depth
determines the working direction.
The TNC calculates the feed rate from the spindle speed.
If the spindle speed override is used during tapping, the
feed rate is automatically adjusted.
The feed-rate override knob is disabled.
At the end of the cycle the spindle comes to a stop.
Before the next operation, restart the spindle with M3
(or M4).
8.3 Dr
illing Cy
cles
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