HEIDENHAIN TNC 426 (280 476) - Manual (Page 277)

250 8 Programming: Cycles
8.3 Cy
cles f
o
r Dr
illing, T
a
pping and Thr
ead Milling
11 At the end of the cycle, the TNC retracts the tool in rapid traverse
to set-up clearance, or — if programmed — to the 2nd set-up
clearance.
Before programming, note the following:
Program a positioning block for the starting point (stud
center) in the working plane with radius compensation R0.
The offset required before countersinking at the front
should be determined ahead of time. You must enter the
value from the center of the stud to the center of the tool
(uncorrected value).
The algebraic sign of the cycle parameters depth of thread
or sinking depth at front determines the working direction.
The working direction is defined in the following
sequence:
1st: Depth of thread
2nd: Depth at front
If you program a depth parameter to be 0, the TNC does
not execute that step.
The algebraic sign for the cycle parameter thread depth
determines the working direction.