The Fanuc G81 Drilling Cycle is a fundamental canned cycle used in CNC programming for simple drilling operations. It’s designed to streamline the drilling process, allowing for rapid and precise drilling at specified coordinates without the need for complex programming.
Usage Format
The basic syntax for the G81 Drilling Cycle is as follows:
G81 X... Y... Z... R... K... F...
Where:
- X and Y are the coordinates of the hole position.
- Z is the depth to which the tool will drill.
- R is the position of the plane above the part where the drill starts and ends.
- K is the number of times the cycle is repeated (optional).
- F is the feed rate for the drilling operation.
Explanation
When the G81 command is executed, the machine performs the following sequence:
- Rapid traverse to the specified X and Y position.
- Rapid traverse to the R plane position.
- Drill at the specified feed rate from the R plane to the Z depth.
- Retract rapidly to either the initial level or the R plane, depending on whether G98 or G99 is used.
Example
Let’s consider a scenario where we need to drill four holes in a square pattern:
%
O1000
T01 M06 (Tool change to drill)
G90 G54 G00 X0 Y0 (Move to start position)
S500 M03 (Spindle speed 500 RPM, start spindle)
G43 H01 Z1 M08 (Tool length compensation, move to 1 inch above part, coolant on)
G81 R0.1 Z-0.5 F3.0 (G81 drilling cycle, R plane at 0.1 inch, drill to -0.5 inch, feed rate 3 inches/min)
X1.0 Y0 (Drill at X1.0 Y0)
X1.0 Y1.0 (Drill at X1.0 Y1.0)
X0 Y1.0 (Drill at X0 Y1.0)
X0 Y0 (Drill at X0 Y0)
G80 (Cancel drilling cycle)
G00 Z1 M09 (Move to 1 inch above part, coolant off)
M30
%
Text Diagram
Here’s a simple text representation of the drilling pattern:
(0,1) *---* (1,1)
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(0,0) *---* (1,0)
Each asterisk (*) represents a drilled hole at the corresponding X and Y coordinates.