Tapping on a turning center (without canned cycles)

Unless your Fanuc controlled turning center came with live tooling, it’s

likely that you don’t have canned cycles (G80-G89) like those you find on

machining centers. You might have G74 and G75, the multiple repetitive

cycles for grooving (or cross drilling) and peck drilling, but nothing that

will help with tapping.

While this might be considered a severe oversight on Fanuc’s part, it is not

at all difficult to program a tapping operation for machines that don’t have a

tapping cycle. If you’re machine doesn’t have a C axis (or indexer) in the

spindle and live tooling, you’ll only be tapping one hole – at the workpiece

center – so programming will not be very difficult.

Here are the commands for tapping, starting with the turret index

command that selects the tap. Be sure to read the important notes that follow

prior to using this program segment.

• .

• .

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• N065 T0505 M41 (Select ½-13 tap, select low range)

• N070 G97 S500 M03 (Start spindle at 500 RPM)

• N075 G00 X0 Z0.25 M08 (Rapid to approach position, start coolant)