Tapping (G63)

Syntax example for XY-plane:

G63 Z<expr> F<expr> <spindle_name><expr> (modal)

G63 Tapping

Z<expr> Target position

F<expr> Feedrate

<spindle_name><expr> Spindle speed consisting of spindle name in accordance with[1]-18 and mathematical expression

For this kind of tapping (G63) the spindle is operated by the CNC in conjunction with the traverse path. In this case an exact dynamically adaptation of the spindle and the infeed motion of the axes is done. So a compensatory chuck is not necessary. The programmed feedrate must fit to the programmed spindle speed and the thread lead and is calculated to:

Feedrate F [mm/min] = Spindle speed S [rpm] * Thread lead [mm/rev]

G63 is deselected by the selection of a different modal block type (e.g. linear movement G01). A non-modal block type (e.g. dwell time with G04) does not deactivate G63.

The path feedrate (F-word) and the spindle speed (S-word) do not necessarily need to be specified in the same NC-block as G63. The last values programmed must always taken when computing the feedrate.

An error message is output if path feedrate or spindle speed are equal to zero with G63 selected.

No spindle M-functions (M03, M04, M05, M19) can be programmed during G63 for the spindle.

Notice
It must be ensured that the spindle has stopped before G63 is selected. This can be achieved by programming M05 (stop spindle) or M19 (position spindle) beforehand.

Cutting of a left-hand thread or retraction from a threaded bore are programmed with negative S-value.

Programming example 1

A thread with a lead of 1.25 mm and a depth of 50 mm is to be drilled. With a programmed spindle speed S of 200 rpm the calculated feed F is:

F = 200*1.25 = 250 mm/min

:
G63 Z-50 F250 S200 (Tapping) 
Z50 S-200 (Retraction from threaded bore) 
G01 F100 X100 ... (Deselection of tapping, linear arinterpolation) 
:

Programming example 2

%Tapping
N05 X0 Y0 Z0
N10 G91
N20 M03
S100 X100 M19 S.POS180 Z100 (Positioning tool and spindle)
N30 G63 Z-100 F300 S200 (Tapping)
N40 Z100 S-200 (Retraction from threaded bore 1)
N50 G01 X200 F3000 M5 (Positioning tool and spindle)
N60 G63 Z-70 F300 S200 (Tapping)
N70 Z70 S-200 (Retraction from threaded bore 2)
N80 M05 G01 X300 F1000 (Deselection of tapping, linear interpol.) 
N90 M30