How to Make a Homemade Periscope with Cardboard and Mirrors: A Fun STEM Project for Kids

Have you ever wanted to see around corners like a spy or peek over a wall without being noticed? A homemade periscope is the perfect gadget to make that happen—and the best part? You can build one with just a few simple materials!

This DIY periscope is not only a fantastic kids science project, but it’s also a great way to learn about light reflection and optical science. Whether you’re a young inventor, a parent looking for a fun weekend activity, or a STEM educator planning a hands-on lesson, this easy home experiment is sure to spark curiosity and creativity.

In this guide, we’ll walk you through the steps to create your very own cardboard periscope using mirrors and everyday household items. Let’s dive in!

Why Build a Periscope? The Science Behind the Fun

Before we jump into construction, let’s explore why a periscope works. A periscope uses mirrors to reflect light, allowing you to see objects that aren’t in your direct line of sight. This principle is used in submarines, tanks, and even some security cameras!

• How Light Reflection Works: When light hits a mirror, it bounces off at the same angle it arrived (the law of reflection). By positioning two mirrors at 45-degree angles inside a tube, you can redirect light from one end to the other, letting you “see around” obstacles.
• Real-World Applications: Periscopes aren’t just for spies—they help submarines navigate underwater and allow doctors to see inside tight spaces during surgeries!

This fun STEM activity is a great way to introduce kids to simple optics while keeping them engaged with a creative project.

Materials You’ll Need

The best part about this DIY periscope is that you probably already have everything you need at home:

• Cardboard tube (from a paper towel or wrapping paper roll)
• Two small mirrors (or mirror sheets, cut to size)
• Scissors or a craft knife (adult supervision recommended)
• Tape or glue
• Ruler and pencil
• Decorative materials (markers, stickers, or paint to personalize your periscope)

Pro Tip: If you don’t have a cardboard tube, you can make one by rolling and taping sturdy cardboard into a rectangular or cylindrical shape.

Step-by-Step: Building Your Homemade Periscope

Step 1: Prepare the Cardboard Tube

If you’re using a paper towel roll, it’s already the perfect shape. For a longer periscope, tape two tubes together. If you’re making a rectangular periscope, fold and tape cardboard into a long box shape.

Step 2: Cut the Mirror Slots

• Measure and mark two diagonal slots at opposite ends of the tube (each at a 45-degree angle).
• Carefully cut the slots—this is where the mirrors will sit.

Step 3: Insert the Mirrors

• Slide the mirrors into the slots so they face each other.
• Secure them with tape or glue, ensuring they stay at a 45-degree angle.

Step 4: Test and Adjust

Look through the bottom opening—can you see what’s above or around the corner? If not, adjust the mirrors until the reflection is clear.

Step 5: Decorate Your Periscope

Now for the fun part! Use markers, stickers, or paint to make your DIY periscope uniquely yours. Camouflage for spy missions? Bright colors for a science fair? The choice is yours!

Creative Ways to Use Your Periscope

Now that your homemade periscope is ready, here are some fun ways to put it to use:

• Spy Games: Play hide-and-seek or create a secret mission where players must spot objects without being seen.
• Nature Exploration: Observe birds in high nests or peek over tall grass during a hike.
• Science Fair Project: Demonstrate how light reflection works and compare different mirror angles.
• Underwater Adventure Pretend Play: Turn a cardboard box into a submarine and use your periscope to “scan the ocean.”

Conclusion: A Simple Project with Big Learning Potential

Building a homemade periscope is more than just a crafty DIY project—it’s a hands-on way to explore light reflection, problem-solving, and creativity. Whether you’re a kid experimenting with simple optics, a parent looking for an educational weekend activity, or a teacher planning a STEM lesson, this easy home experiment is a winner.

So, what are you waiting for? Grab some cardboard, mirrors, and your imagination—it’s time to build, learn, and explore!

• Challenge Yourself: Can you design a periscope that looks left and right instead of up and down?
• Share Your Creation: Post a picture of your DIY periscope online and tag #YoungInventors!
• Explore More: Try other science for kids projects, like making a kaleidoscope or a sundial.

The world is full of hidden wonders—now you have the perfect tool to discover them! 🚀