Here’s a clear, kid‑friendly way to make a working cardboard crane for a school project, step by step, plus how to turn it into a nice report or presentation.

What you’ll be making

You’ll build a small cardboard crane with a pulley and a hook that can lift light objects (like an eraser or a small toy).

Materials you need

Try to gather these before you start:

  • Cardboard (cereal box or any box)
  • Toothpicks (or skewers / stiff straws)
  • String or wool thread
  • 1–2 paper clips (for the hook)
  • Scissors or a craft knife (ask an adult for help)
  • Glue (white glue or hot glue, with adult help)
  • An old pencil / pen tube (optional, for pulleys/axles)
  • Ruler and pencil for measuring

Optional extras:

  • Markers/paint to decorate
  • Extra cardboard for a “cabin” or counterweight

Step‑by‑step: How to make the crane

1. Build the base (the ground)

This keeps your crane stable so it doesn’t fall over.

  1. Cut a rectangle of cardboard about 20 cm x 15 cm.
  1. If the cardboard is thin, glue two layers together to make it stronger.
  1. Let it dry flat so it stays straight.

You can think of this as the “ground” your crane stands on.

2. Make the crane arm (boom)

The arm is the long part that sticks out and holds the hook.

  1. Cut two identical cardboard strips: about 20 cm x 4 cm.
  1. On one end of each strip, cut the tip at an angle (about 45–50°). This will be the “front” of the arm.
  1. Lay the two strips side by side, with a small gap (about 3 cm) between them.
  1. Cut several toothpicks to span that gap. Glue them between the strips like ladder rungs, every 3–4 cm.
  1. Let the glue dry; now you have a strong, 3D arm.

This ladder‑style arm is stronger than a single flat strip and looks more like a real crane.

3. Attach the arm to the base

Now you join the boom to the base so it stands up.

  1. Stand the arm upright on one short side of the base, with the angled end facing outward.
  1. Glue the angled ends firmly to the base. Hold it until it grips.
  1. Cut two small triangular pieces of cardboard and glue them on each side where the arm meets the base, like braces.

These extra supports stop the arm from wobbling or bending when it lifts something.

4. Make the pulley wheels (simple version)

If your teacher just wants a basic model, you can skip fancy wheels and run the string over a toothpick. If you want a more realistic pulley:

  1. Cut four cardboard circles, about 3 cm across.
  1. Glue two circles together to make one thicker wheel; repeat for the second wheel.
  1. Carefully poke a hole through the center of each wheel.
  1. Slide a short piece of pen tube or toothpick through the hole to make an axle and glue it in place.

You now have small pulley wheels the string can roll over.

5. Install the pulleys on the crane

You’ll use one pulley on the tip of the arm and one near the base to guide the string.

  1. At the very front of the arm (the angled end), fix one pulley wheel between the two sides of the arm so it can spin.
  1. Near the bottom where the arm joins the base, attach the second pulley or a smooth toothpick crosswise for the string to turn around.

This makes your crane look and act more like a real lifting machine.

6. Build the string holder (spool and axle)

This is the “winch” you turn to raise and lower the hook.

  1. Cut two rectangles of cardboard about 8 cm x 4 cm each.
  1. Glue them upright on the base, behind the arm, with about 3 cm between them (the same spacing as your arm).
  1. Cut a cardboard circle about 5 cm across; this is your spool.
  1. Push a toothpick through the center of the circle and glue it so the circle is fixed to the toothpick.
  1. (Optional) Glue a half‑length toothpick near the edge of the circle as a little handle for turning.
  1. Poke holes in the two upright rectangles and slide the toothpick (axle) through so the spool hangs between them and can spin.

You’ve just created a tiny hand‑powered winch that controls the crane’s string.

7. Add the string and hook

Now the crane can actually lift things.

  1. Tie one end of the string firmly to the axle or spool.
  1. Wrap the string around the spool a few times.
  1. Lead the free end of the string up and over the pulley at the tip of the arm, then back down.
  1. Unfold a paper clip into a hook shape and tie the string to it.

Turn the spool to wind the string and your hook will go up; unwind it and the hook will go down.

8. Make a load platform (optional but great for school)

Teachers love when you show how the model is used.

  1. Cut a square of cardboard about 10 cm x 10 cm.
  1. Cut two pieces of string about 25 cm long each.
  1. Slide the strings under the square in a cross shape (like a plus sign), then tape or glue each end to the four sides.
  1. Bring the loose ends of the strings together above the center and tie them into a loop.
  1. Hang that loop on your paper‑clip hook.

Now you can put small objects on the platform and lift them with your crane.

Safety and neatness tips

  • Ask an adult before using hot glue or a craft knife.
  • Measure your pieces carefully so everything lines up and looks clean.
  • Don’t try to lift heavy objects; cardboard can bend easily.
  • Let all glued joints fully dry before testing the crane.

How to explain this in your school project

In your report, poster, or slides, you can break it into mini‑sections like this:

  • Introduction :
    • What is a crane and where is it used (construction sites, ports, etc.)
    • Why you chose to make this model
  • Materials and Method :
    • List of materials
    • Short description of each step (base, arm, pulley, string, hook)
  • Science/Engineering Idea :
    • Explain that a crane uses pulleys and levers to make lifting easier.
* Mention that the string changes direction over the pulley so you can pull from one place while the hook moves in another.
  • Results and Testing :
    • Describe what objects you tried lifting (eraser, small toy, coins).
    • Note any problems (arm bending, base tipping) and how you fixed them (more supports, wider base).
  • Conclusion :
    • What you learned about simple machines (pulleys, levers).
* How you might improve the crane (stronger materials, electric motor, better pulleys).

You can also add photos of your build at each stage so your teacher can see your process.

Simple meta description (for SEO use)

Learn how to make a crane for a school project step by step using cardboard, string, and simple pulleys, with clear instructions and tips for a science or STEM presentation.

TL;DR:
Cut a strong cardboard base and a ladder‑style arm, glue them together with supports, add small pulleys and a spinning string spool, tie on a paper‑clip hook and a little load platform, then use the spool to lift small objects for your school project.

Information gathered from public forums or data available on the internet and portrayed here.