The G84 tapping cycle is commonly used in CNC (Computer Numerical Control) machining to perform right-hand threading operations with a tap. This cycle automates the process of tapping, making it efficient and precise.

Usage Format

The basic format for a G84 command is as follows:

G84 X... Y... Z... R... P... F...

Where:

• X and Y are the coordinates for the hole’s location.
• Z is the depth to which the tap will go.
• R is the plane to which the tap will retract.
• P is the dwell time at the bottom of the hole.
• F is the feed rate or the speed at which the tap will move.

Explanation

When the G84 cycle is initiated, the machine will first move the tap to the specified X and Y coordinates. Then, it will plunge the tap to the Z depth at the F feed rate. After reaching the desired depth, the tap dwells for the P duration to ensure proper threading. Finally, the tap retracts to the R plane, ready for the next operation.

Example

Here’s a simple example of a G84 tapping cycle in action:

N10 G00 X30 Y50 (Move to the starting position)
N20 G43 Z5 H01 (Tool length compensation)
N30 M06 T02 (Tool change to tap)
N40 G98 G84 Z-10 R2 P100 F0.5 (Tapping cycle)

In this program:

• The tap moves to the coordinates X30, Y50.
• Tool length compensation is set with G43, and the tool is changed to T02.
• The G84 cycle is initiated, tapping to a depth of Z-10 at a feed rate of 0.5, with a dwell time of 100 milliseconds, and retracting to a plane of R2.