DIY Open & Closed Gear Sign: Transforming Paper Into Dynamic Engineering Art

Hey everyone! Get ready to transform everyday paper and cardboard into a stunning, fully functional gear sign—no 3D printing required! Not only is this project cost-effective, but it also offers a hands-on introduction to basic mechanical principles. Perfect for decorating your home, engaging kids in STEM, or adding a unique conversation piece to any space.

🔧 Inspiration

This project is based on the brilliant HAGURUMA "Open/Closed" sign by Yosuke Ikeda 🛠️. The sign uses an engaging gear mechanism to smoothly transition between “Open” and “Closed” states. Check out the original design here:

📺 Watch the video!

💡 Why This DIY Tutorial Stands Out

While there are many tutorials available for making such signs, many of them are complex and require 3D printing, which is not accessible to everyone. In contrast, this tutorial is:

1. Simple – Only 3 main components to build a fully functional gear sign!
2. Accessible – Unlike complex versions that require 3D printing, this design uses inexpensive, easy-to-find materials like paper and cardboard!
3. Educational – Great for parents, teachers, and students, blending art, mechanics, and hands-on creativity into one fun project!
4. Customizable – Want to personalize your sign? Get creative by painting, decorating, or even adding your own words!

So, let’s bring gears to life and start building!

1. Patterns (attached)
2. Cardboard Sheet (at least 25 cm x 25 cm)
3. Quantity: 2
4. Push Pins
5. Quantity: 2 (plus extras)
6. Brass Plate Fasteners
7. Quantity: 2
8. Scissors
9. Glue
10. Masking Tape
11. Quantity: 1 roll (per 10 students)
12. Duct Tape or Glue Gun
13. Quantity: 1 (per 10 students)
14. Marker/ Construction Paper (Optional for decoration)

🔄 What is a Gear?

A gear is a rotating wheel with teeth that interlocks with another gear to transfer motion and force. When one gear turns, it makes the other move—either in the same or opposite direction, depending on their arrangement.

⚙️ How Gears Work in Our Project

In this Open/Closed Gear Sign, we use gears to rotate letters in sync, so the sign smoothly shifts between "Open" and "Closed." This happens because of how gears interact with each other!

📏 What is a Gear Ratio?

A gear ratio is the relationship between the number of teeth on two gears that are meshed together. It tells us how fast one gear will spin compared to another.

🔹 Formula:

Gear Ratio=Teeth on Driving Gear/ Teeth on Driven Gear​

🔹 Example:

If the driving gear has 10 teeth and the driven gear has 20 teeth, the gear ratio is:

Teeth on Driving Gear/ Teeth on Driven Gear​= 10/20= 2:1

This means the driven gear rotates half turn when the driving gear rotate a full turn

🚀 Real-Life Examples of Gears & Gear Ratios

1. Bicycles: The chain moves between different-sized gears to adjust speed and force.
2. Clocks: Small and large gears work together to keep time accurately.
3. Cars: Gears in the transmission system help change speed efficiently.

🔥 Why This Matters for Your DIY Sign!

In our project, the gears must be correctly aligned so they rotate smoothly and in sync. If the ratio isn’t balanced, the letters won’t change position correctly. Understanding how gears work helps us build better projects and understand real-world mechanics!

Now, let's start building your own interactive gear sign!

Print & Cut Patterns:

Print the worksheet and pattern templates provided.

Stick the pattern on the cardboard.

Cut out all shapes, including gears, letters, circles, and squares.

Cut Cardboard Base:

Cut a 25 cm x 15cm rectangle from your cardboard sheet. This will be the base of the open and close sign.

a. Central Holes: With a push pin, create a small hole at the center of each gear for rotation.

b. Stack for Stability: Pair up two gears with glue gun to increase thickness and enhance the rotational mechanism.

Test Fit: Temporarily assemble circle, gear, and cardboard base with a push pin to ensure proper alignment and smooth movement.

Secure: Once satisfied with the gear alignment, use a pencil/pen to enlarge the hole on the cardboard, secure all parts using brass plate fasteners to ensure a stable, rotating mechanism.

1. Attach the letters “o” and “p” to one gear (see picture 1).
2. Cut two rectangular strips (4 cm x 1 cm), punch a small hole at the top of each and attach them to the gear (see picture 2).
3. Attach letters “e” and “s” to the other gear (see picture 3).
4. Ensure proper positioning for the “Open/Closed” display (see picture 4).

Smooth Operation: Rotate the sign several times. Ensure that all gears mesh properly and rotate smoothly.

Fine-Tuning: Adjust the positions of the components if necessary.

Personalize your project: Decorate your gear with markers, construction paper and your creativity :)