Feeds and speeds calculation in CNC Programming - Mini Project: Build & Apply

Feeds and Speeds Calculation

📖 Scenario: You work in a small machine shop. You want to automate the calculation of the cutting speed and feed rate for your CNC milling machine. This helps you set the machine correctly for different tools and materials.

🎯 Goal: Build a simple Python script that calculates the cutting speed (in meters per minute) and feed rate (in millimeters per minute) based on tool diameter, spindle speed, and feed per tooth.

📋 What You'll Learn

Create variables for tool diameter, spindle speed, and feed per tooth with exact values

Create a variable for the number of teeth on the tool

Calculate cutting speed using the formula: (π x tool diameter x spindle speed) / 1000

Calculate feed rate using the formula: feed per tooth x number of teeth x spindle speed

Print the cutting speed and feed rate with clear labels

💡 Why This Matters

🌍 Real World

Automating feeds and speeds calculations saves time and reduces errors when setting up CNC machines.

💼 Career

CNC programmers and machinists use these calculations daily to optimize machining processes and tool life.

1

Set up tool and spindle data

Create variables called tool_diameter with value 10 (millimeters), spindle_speed with value 1500 (RPM), and feed_per_tooth with value 0.05 (millimeters).

CNC Programming

# Create variables for tool diameter, spindle speed, and feed per tooth
# Your code here

Need a hint?

Use simple assignment statements like variable = value.

2

Add number of teeth configuration

Create a variable called number_of_teeth and set it to 4.

CNC Programming

tool_diameter = 10
spindle_speed = 1500
feed_per_tooth = 0.05
# Create variable for number of teeth
# Your code here

Need a hint?

Just add one more variable assignment.

3

Calculate cutting speed and feed rate

Calculate the cutting speed and store it in a variable called cutting_speed using the formula (3.1416 * tool_diameter * spindle_speed) / 1000. Calculate the feed rate and store it in a variable called feed_rate using the formula feed_per_tooth * number_of_teeth * spindle_speed.

CNC Programming

tool_diameter = 10
spindle_speed = 1500
feed_per_tooth = 0.05
number_of_teeth = 4
# Calculate cutting_speed and feed_rate
# Your code here

Need a hint?

Use the exact formulas given and assign results to the correct variable names.

4

Display the results

Print the cutting speed with the label Cutting speed (m/min): and the feed rate with the label Feed rate (mm/min):. Use print statements.

CNC Programming

tool_diameter = 10
spindle_speed = 1500
feed_per_tooth = 0.05
number_of_teeth = 4
cutting_speed = (3.1416 * tool_diameter * spindle_speed) / 1000
feed_rate = feed_per_tooth * number_of_teeth * spindle_speed
# Print cutting_speed and feed_rate with labels
# Your code here

Need a hint?

Use print(f"Label: {variable}") to show the values clearly.