Project: Lego Mini-Fig

Objectives and Overview

This project tests the ability to use digital calipers to take accurate measurements of a physical object. You’ll measure a Lego mini-fig with the goal of using those measurements to create an object or tool that they can wear.

Lesson Objectives

  • Use digital calipers to take a precise measurement of a physical object.
  • Demonstrate precision design skills to create an object or tool for a Lego mini-fig.

Lego Mini-Fig Challenge

For this project, your task is to create an object or tool for a Lego mini-fig!


  • Use the digital calipers to measure the part of the mini-fig you want to interact with
    • Head: hair, hats, headphones
    • Hands: tools, pens, eating utensils
    • Legs/feet: cars, scooters, chairs
  • Design and print a small prototype to make sure it fits
  • Design the rest of the object with these dimensions in mind
  • Upload your design for 3D printing


Here are some examples that you can use for reference or inspiration.

This first example shows some mini-figs with a variety of hats. If you want to do this, you’ll need to use the digital calipers to measure the head.

Eight mini-Figs with a variety of hats

This example shows a jester mini-fig with a swappable 3D printed hat that’s been painted.

Jester mini-fig with a 3D printed jester cap alternative

This last example shows a mini-fig with a vest and a 3D printed tool. If you want to make a tool you’ll need to use the digital calipers to measure their hand.

Mini-fig with 3D printed vest and tool