HEIDENHAIN TNC 426 (280 476) - Manual (Page 254)

HEIDENHAIN TNC 426, TNC 430 227
8.3 Cy
cles f
o
r Dr
illing, T
a
pping and Thr
ead Milling
TAPPING NEW with floating tap holder
(Cycle 206)
1 The TNC positions the tool in the tool axis at rapid traverse FMAX
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. and — if programmed — to
the 2nd set-up clearance with FMAX.
4 At the set-up clearance, 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.
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.