Free STEM and engineering projects for kids
The Peabody Workshop has 32 free engineering and STEM projects for kids to build at home, from a marble run to a hydraulic arm. Every project has step-by-step pictures that Peabody reads aloud, a list of what you need, and a test to run, then three ways to make it better. Free through 2026.
32 projects to build at home
| Project | Ages | The idea | Time | Cost |
|---|---|---|---|---|
| Wall Marble Run | K–3rd | Things roll downhill, and a gentle slope makes a slower ride. | 30 min | free |
| Paper Cup Tower | K–2nd | A wide bottom holds a tall tower up. | 20 min | about $2 |
| Shoebox Guitar | K–3rd | A tighter, thinner band wiggles faster and sounds higher. | 30 min | free |
| Ramp Races | K–3rd | A steeper ramp makes a faster car. | 20 min | free |
| Foil Boat | K–4th | A wide boat pushes away lots of water, so it floats with more on board. | 20 min | about $1 |
| The Pigs' House vs. the Wolf | K–3rd | Triangles and wide, heavy bottoms stand up to the wind. | 30 min | free |
| Paper Airplane Lab | 1st–5th | Wings push on the air, and where the weight sits decides if a plane glides or dives. | 30 min | free |
| Craft-Stick Catapult | 1st–5th | A lever stores your push in the bent stick, then throws it. | 30 min | about $3 |
| Straw Rocket | 1st–5th | Your breath pushes the rocket off the straw, and the angle decides how far it goes. | 30 min | about $1 |
| Index-Card Bridge | 3rd–6th | Folding paper makes it stiff, so it holds far more. | 45 min | about $1 |
| Light-Up Card | 3rd–8th | Electricity only flows round a full loop: one gap and the light goes out. | 45 min | about $5 |
| Hydraulic Robot Arm | 5th–8th | Push water into one syringe and it pushes the other, because water won't squash. | 120 min | about $8 |
| Elephant Toothpaste | 2nd–8th | Yeast splits peroxide into water and oxygen super fast, and soap catches the oxygen as foam. | 15 min | about $4 |
| Stretchy Slime | 3rd–8th | The activator links glue's long chains into a net, so runny glue turns into stretchy slime. | 25 min | about $5 |
| Oobleck | K–8th | Oobleck goes hard when you push it fast and runny when you go slow. | 10 min | about $2 |
| Fizzy Volcano | K–8th | Baking soda and vinegar make a gas, and soap turns the gas into foamy lava. | 15 min | about $2 |
| Salt Lava Lamp | K–8th | Oil floats on water, and salt can drag it down for a ride. | 15 min | about $2 |
| Magic Milk | K–8th | Soap grabs fat, and as it races across the milk the colours ride along. | 10 min | free |
| Rain Cloud in a Jar | K–8th | A cloud holds water until it gets too heavy, and then it rains. | 10 min | free |
| Walking Water Rainbow | K–8th | Water can climb up through tiny gaps, even uphill. | 15 min | free |
| Giant Bubbles | K–8th | Soap makes water stretchy enough to wrap around air. | 20 min | about $3 |
| Soda Geyser | 2nd–8th | Gas hiding in soda rushes out all at once when it finds rough places to make bubbles. | 15 min | about $4 |
| Secret Message | K–8th | Some colours change when they meet a base, like baking soda. | 15 min | about $2 |
| Potato Power | 3rd–8th | Two different metals in a juicy potato make a battery, and a chain of them adds up. | 30 min | about $6 |
| Squishy Circuits | 1st–8th | Salty dough carries electricity and clay stops it, so you can sculpt a circuit. | 30 min | about $7 |
| Static Magic | 2nd–8th | Rubbing moves electric charge, and charges pull and push without touching. | 20 min | about $1 |
| Tube Flashlight | 3rd–8th | A switch is a gap in the loop that you can open and close. | 40 min | about $6 |
| Egg Drop Challenge | 3rd–8th | Slow the fall and soften the stop, and a raw egg can survive a big drop. | 45 min | about $3 |
| Chain Reaction Machine | 2nd–8th | A little push sets stored energy free, and it passes from one thing to the next. | 45 min | free |
| Balloon Hovercraft | 2nd–8th | A cushion of air lifts the disc, so there is almost no rubbing to slow it down. | 30 min | about $3 |
| Cup Zipline | 2nd–8th | Gravity pulls the rider down the slope, and a steeper slope is a faster ride. | 30 min | about $3 |
| Balloon Car | 3rd–8th | Push air out the back, and the air pushes the car forward. | 45 min | about $3 |
How a Workshop project works
- Pick what you have. Say which supplies are at home and see which projects you can start now.
- Follow the pictures. Each step is drawn, short, and read aloud.
- Test it. Measure what your build does: how far it flies, how much it holds.
- Make it better. Each build has three ideas to change one thing and test again.
Safety
A step that uses something sharp, hot or plugged in is marked, and a grown-up does that part. A grown-up can turn off the projects that need those tools from the parent console. The marks used are: sharp, hot, plugs in, small parts, coin battery, magnets, balloons, careful liquid, not food.
What you need
Most projects use ordinary things: cardboard tubes, a marble, paper cups, index cards, a shoebox, rubber bands, a pencil, flat cardboard, some books, a toy car, foil, pennies.
Questions parents ask
Are the projects free?
Yes, free through the end of 2026, with no ads and no sign-up to start.
What ages are they for?
The table lists the ages of each project. A younger child can try a project above their age with a grown-up helping.
Is this STEM or engineering?
Both. Each project is a small engineering problem with a science idea inside it, and a child tests and improves it like an engineer.
Want more? Science games for kids, free arcade games and a free homeschool plan.
Checked against how Peabody works on 18 October 2026. Written with help from AI, from Peabody's own code and library. Peabody is a learning app, not an assessment: if you're worried about your child's learning, talk to their teacher.