G84 Rigid Tapping Program Example

G84 Rigid Tapping Program Example

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G84 is a tapping canned cycle.

G84 taps holes.

This simple part has four M12 holes, drilled, countersunk and tapped. The datum is the centre of the part so the holes positions are.

X55. Y55.
X-55. Y55.
X-55. Y-55.
X55. Y-55.

G84 Rigid Tapping Program Example

Here is the CNC code

The machine first moves to X-55. Y-55. and rapids the Z axis to 3mm above the part.

The G95 selects feed per revolution which means we only need to program the tap pitch for the feed-rate.

See full rigid tap G84 Rigid Tapping Program Example

The M29 engages the rigid tapping mode and the S800 is the speed. (It does not start the spindle)

It then rapids the Z axis down to 1mm above the part R1.

The G84 Cycle instructs it to tap a hole 17.mm deep (Z-17.) at a feed of 1.75mm per revolution (F1.75) 

So it feeds at 1.75mm per revolution with the spindle turning clockwise to depth.

At the bottom of the hole it reverses the spindle and feeds back to the initial point.

This initial point was in the line.

This is because of the G98.

If it were G99 it would return to 1mm above the job (R1.)

See explanation of G98 and G99

Once the cycle is active each time it sees a position it repeats the tapping process.

When the G80 is programmed it no longer taps holes.

Single block and feedhold do not work in a tapping cycle.

Why? You ask.

IT BUSTS THE TAP

Now watch the video to see it all in action (not breaking the tap).

Thanks

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