Drilling operation (G81 canned cycle) in CNC Programming - Mini Project: Build & Apply

Drilling Operation Using G81 Canned Cycle

📖 Scenario: You are programming a CNC machine to drill holes in a metal plate. The machine uses G-code commands. To drill multiple holes efficiently, you will use the G81 canned cycle command.This project will guide you step-by-step to create a simple CNC program that drills three holes at specified positions.

🎯 Goal: Build a CNC program that drills three holes using the G81 canned cycle command. You will define the hole positions, set the drilling parameters, and output the final G-code program.

📋 What You'll Learn

Create a list of hole positions with exact X and Y coordinates

Define drilling parameters such as depth and feed rate

Use the G81 canned cycle command to drill holes at each position

Output the complete CNC program with proper formatting

💡 Why This Matters

🌍 Real World

CNC programmers use canned cycles like G81 to automate repetitive drilling tasks efficiently and reduce programming time.

💼 Career

Understanding G81 canned cycles is essential for CNC operators and programmers to create precise and efficient drilling programs in manufacturing.

1

Define Hole Positions

Create a list called holes with these exact hole positions as tuples: (10, 10), (20, 10), and (30, 10).

CNC Programming

# Create the list holes with the specified positions
# Your code here

Hint

Use a Python list with tuples for each hole position.

2

Set Drilling Parameters

Create variables called drill_depth set to -5 and feed_rate set to 100 to define the drilling depth and feed rate.

CNC Programming

holes = [(10, 10), (20, 10), (30, 10)]
# Define drill_depth and feed_rate variables
# Your code here

Hint

Use simple variable assignments for depth and feed rate.

3

Write Drilling Commands Using G81

Create a list called program_lines and add the following lines exactly: "G90 G94 G17" for absolute positioning, "G21" for millimeters, and then use a for loop with variables x and y to add a G81 command for each hole in holes with the format "G81 X{x} Y{y} Z{drill_depth} F{feed_rate}". Finally, add "G80" to cancel the canned cycle.

CNC Programming

holes = [(10, 10), (20, 10), (30, 10)]
drill_depth = -5
feed_rate = 100
# Create program_lines list and add initial setup lines
# Use a for loop with x, y to add G81 commands for each hole
# Add G80 to cancel canned cycle
# Your code here

Hint

Use a list to hold program lines and a for loop to add G81 commands with f-strings.

4

Output the Complete CNC Program

Use a for loop to print each line in program_lines exactly as it is.

CNC Programming

holes = [(10, 10), (20, 10), (30, 10)]
drill_depth = -5
feed_rate = 100
program_lines = [
    "G90 G94 G17",
    "G21"
]
for x, y in holes:
    program_lines.append(f"G81 X{x} Y{y} Z{drill_depth} F{feed_rate}")
program_lines.append("G80")
# Print each line in program_lines
# Your code here

Hint

Use a simple for loop to print each line exactly.