Threading is part of almost every component that we machine on a cnc machine.
You can cut tapered threads with G76 threading cycle read this G76 Tapered Threading.
G92 Threading Cycle Format
G92 X.. Z.. F..
X = Current diameter of the thread pass
Z = End position of the thread in Z-axis
F = Threading feedrate in in/rev (Thread Pitch)
G92 is briefly explained here G92 Threading Cycle.
G92 Threading Cycle Format for Taper Threading
G92 X.. Z.. R.. F..
G92 X.. Z.. I.. F..
The R or I parameter in G92 threading cycle is the tapered value. Note that R or I is given as Radius value.
On some controls there is no ‘R’ value for taper but you will use ‘I’ value for taper in G92 threading cycle.
G92 Taper Threading Cycle Example
N10 T303 N20 G97 S450 M03 N30 G00 X90. Z25.4 M08 N40 G92 X74.996 Z-70. I-3.051 F3.175 N50 X74.601 N60 X74.206 N70 X73.811 N80 X73.416 N90 X73.316 N100 G00 Z25.
As you can see the above cnc programming example uses I value to specify the taper in the G92 threading cycle.