G81, G82 & G83 - Drilling Cycles
Description
The drilling cycle commands provide automated drilling operations that combine multiple movements into a single command. These cycles are essential for efficient drilling operations in CNC machining:
- G81 (Simple Drill Cycle): Performs basic drilling with rapid positioning, controlled drilling, and return
- G82 (Drill with Dwell): Same as G81 but includes a dwell time at the bottom of the hole
- G83 (Peck Drilling Cycle): Performs drilling in incremental steps with retraction between cuts
All drilling cycles work with the current plane selection (G17/G18/G19) and can be repeated multiple times using the L parameter. The cycles automatically handle positioning, drilling, and return operations. Return behavior is controlled by G98/G99 commands.
Syntax
Parameters
| Parameter | Description | Used In | Example |
|---|---|---|---|
| X, Y | Drilling position coordinates in working plane | All cycles | X10 Y20 |
| Z | Final drilling depth (bottom of hole) | All cycles | Z-5.0 |
| R | Retract position (safety height above workpiece) | All cycles | R2.0 |
| F | Drilling feedrate (units per minute) | All cycles | F100 |
| P | Dwell time at bottom of hole (milliseconds) | G82, G83 | P500 |
| Q | Peck drilling depth increment per cut | G83 | Q1.0 |
| L | Number of repetitions (L1 = 2 holes, L2 = 3 holes, etc.) | All cycles | L3 |
Note: X, Y, Z, R, and F parameters are required for all drilling cycles. P and Q parameters are optional and used only by specific cycles as indicated.
Drilling Cycle Types
G81 - Simple Drill Cycle
The basic drilling cycle that performs rapid positioning to the XY coordinates, rapid move to R position, controlled drilling to Z depth, and return according to the current return mode.
- Rapid move to XY position
- Rapid move to R position
- Feed to Z depth at specified feedrate
- Return to initial position or R position
G82 - Drill with Dwell
Similar to G81 but includes a dwell time at the bottom of the hole.
- Rapid move to XY position
- Rapid move to R position
- Feed to Z depth at specified feedrate
- Dwell for P milliseconds
- Return to initial position or R position
G83 - Peck Drilling Cycle
Advanced drilling cycle that breaks deep holes into smaller increments with chip evacuation.
- Rapid move to XY position
- Rapid move to R position
- Feed down by Q depth increment
- Rapid retract to R position (chip clearing)
- Repeat steps 3-4 until full Z depth is reached
- Optional dwell at final depth if P is specified
- Return to initial position or R position
Return Mode Control
Drilling cycles support two return modes that control where the tool moves after completing each drilling operation:
G98 - Return to Initial Position
Returns the tool to the Z coordinate where the drilling cycle was started.
G81 X10 Y10 Z-5 R2 F100
G99 - Return to R Position
Returns the tool to the R retract position.
G81 X10 Y10 Z-5 R2 F100
For detailed information about return modes, see the G98/G99 - Drill Cycle Return Modes.
Plane Selection Support
Drilling cycles work with all three coordinate planes. The drilling axis is automatically determined by the current plane selection:
| Plane | Work Axes | Drill Axis | Common Use |
|---|---|---|---|
| G17 (XY) | X, Y positioning | Z drilling | Standard vertical drilling |
| G18 (ZX) | Z, X positioning | Y drilling | Side drilling operations |
| G19 (YZ) | Y, Z positioning | X drilling | Front/back drilling |