Post-processor and G-code output in CNC Programming - Mini Project: Build & Apply

Post-processor and G-code output

📖 Scenario: You work in a small workshop that uses CNC machines. You need to create a simple program that converts a list of machining steps into G-code commands. This helps the CNC machine understand what to do.

🎯 Goal: Build a Python script that takes a list of machining steps and outputs the correct G-code commands as text.

📋 What You'll Learn

Create a list of machining steps with exact values

Add a configuration variable for feed rate

Use a for loop to convert steps into G-code lines

Print the final G-code output

💡 Why This Matters

🌍 Real World

CNC machines need G-code instructions to move tools and cut materials precisely. Post-processors convert design steps into these instructions.

💼 Career

Understanding how to automate G-code generation helps CNC programmers and manufacturing engineers save time and reduce errors.

1

Create the machining steps list

Create a list called steps with these exact tuples: ("move", 10, 20), ("cut", 15, 25), ("move", 20, 30)

CNC Programming

# Create the list called steps with the given tuples
# Your code here

Need a hint?

Use square brackets to create a list. Each step is a tuple with an action and two numbers.

2

Add a feed rate configuration

Create a variable called feed_rate and set it to 100 to use as the speed for cutting.

CNC Programming

steps = [("move", 10, 20), ("cut", 15, 25), ("move", 20, 30)]
# Create feed_rate variable and set it to 100
# Your code here

Need a hint?

Just write feed_rate = 100 on a new line.

3

Convert steps to G-code lines

Create a list called gcode_lines. Use a for loop with variables action, x, and y to go through steps. For each step, add a string to gcode_lines: if action is "move", add "G0 X{x} Y{y}"; if action is "cut", add "G1 X{x} Y{y} F{feed_rate}".

CNC Programming

steps = [("move", 10, 20), ("cut", 15, 25), ("move", 20, 30)]
feed_rate = 100
# Create gcode_lines list and fill it using a for loop over steps
# Your code here

Need a hint?

Start with an empty list. Use a for loop to check each action and add the right formatted string.

4

Print the G-code output

Use a for loop to print each line in gcode_lines.

CNC Programming

steps = [("move", 10, 20), ("cut", 15, 25), ("move", 20, 30)]
feed_rate = 100
gcode_lines = []
for action, x, y in steps:
    if action == "move":
        gcode_lines.append(f"G0 X{x} Y{y}")
    elif action == "cut":
        gcode_lines.append(f"G1 X{x} Y{y} F{feed_rate}")
# Print each line in gcode_lines
# Your code here

Need a hint?

Use a for loop to print each string in the list on its own line.