HEIDENHAIN iTNC 530 (340 422) ISO programming - Manual (Page 253)

HEIDENHAIN iTNC 530 253
8.3 Cy
cles f
o
r Dr
illing
, T
a
p
p
ing
and
Th
read Millin
g RIGID TAPPING NEW (Cycle G207)
The TNC cuts the thread without a floating tap holder in one or more
passes.
See “RIGID TAPPING (Cycle G85),” page 252, for the advantages that
rigid tapping offers over tapping with a floating tap holder.
1 The TNC positions the tool in the tool axis at rapid traverse to the
programmed setup 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
rapid traverse.
4 The TNC stops the spindle rotation at the set-up clearance.
Machine and control must be specially prepared by the
machine tool builder for use of this cycle.
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 total hole depth parameter
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).
Enter in MP7441 bit 2 whether the TNC should output an
error message (bit 2=1) or not (bit 2=0) if a positive depth
is entered.
Danger of collision!
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
at safety clearance below the workpiece surface!