Cars – Engineering for Kids


After we studied all the Simple Machines, we spent a day looking at a complex machine: the car.

Make a Cardboard Car to Sit In

This is a parent-child collaborative project. It’s fun to create a big project to take home. We ask each parent to save and bring to class a box that is big enough for their child to sit in. Then we add paper plates for wheels (fastened on so they can turn), straps so they could wear them over their shoulders and a variety of decorations.

cardboard box cars

To read a full post about this project, and see lots more pictures, go to

Engineering Projects

Make a Car that Rolls

If you want to just make car crafts, it’s easy to offer a creation station with lots of options for bodies, wheels and axles, and they can stick them together however they want. If you want them to design a car with wheels that actually roll, that’s trickier. And if you want to have “motorized” cars that move on their own, that adds complexity!

I’ve explored lots of different ideas – learn about them all: Designing a Car Project. They range from very simple cars from toilet paper tubes, skewers and cardboard wheels to much more sophisticated projects.

Here are the ones we’ve done in class. We always build the cars in the first part of class and let them play with them for a while, then in the second part of class, we “motorize” the car.

Plastic Car / Retractable Badge Motor. We used corrugated plastic bodies, taped on straw wheel bearings, threaded wooden dowels through those and attached wooden wheels. We added a retractable badge clip to motorize it so it could run on its own as a pull-back and release car. After we tested those and played for a while, then we explained how the bigger a wheel’s diameter, the further it rolls on each revolution. We added CD wheels. See a tutorial:

Model A

Cardstock Car / Rubber Band Motor: This car body is made out on a piece of cardstock, and is powered by winding a rubber band. This is a little less prep and lower cost than the method above, and works just as well. Here’s the tutorial.


Cardstock Car / Motorized Fan. This one, again, has a body that’s folded from a cardstock template. I found some wheels and axles that don’t require any prep time like the previous designs, and we motorized it with a fan. Find the tutorial here:


Clothespin Racer: At one point we thought of using a flywheel style pull-back car mechanism, and checked whether we could buy kits with these. We didn’t find kits, but we did learn that pull-back cars are cheap – about 35 cents each. So, we invented these clothespin racers, which are quick, simple to build, fun and zippy. Find a tutorial at:


Art Projects

Process art – Monster Truck Painting: We put paper on a table, then poured three blobs of paint on the table, and added three “monster truck” toys that had big treads on the tires. Kids drive the truck through the paint and it leaves tracks all over the paper. We put toilet paper roll bumpers all around the table so they wouldn’t be constantly flying off the table. This was a big hit with our 2 to 4-year-olds.


Product art: One year, we got wooden cars from Discount School supply and painted them with metallic paints. At ~$2 a car, this is a pricier project than we usually do. (And the results aren’t beautiful when three year olds are paining..)


Assembly Line: There are lots of cute ideas online for how to make a car using a half paper plate for the body, and geometric shapes for the wheels, windows, etc. We took that play up a notch by creating a conveyor belt assembly line for kids to build the cars on. Learn more:

assembly line

You could also offer: coloring pages with pictures of cars, or large paper on the floor that kids can draw their own cities and roads on to drive cars around.

Free Play / Math / Physics Experiments

Sorting: We had a collection of toy vehicles kids could sort into “cars” and “not cars.”

Race a car: We set out blocks, black foam core boards or plastic panels, ramps from Kodo Engineering, toy cars, and a yard stick. Kids could build ramps, race cars down them, and measure how far their cars went. They could notice whether the distance travelled was affected by how steep the ramp was.

Free play: We filled the sensory table with kinetic sand and toy cars with treads to drive around in it. We had a steering wheel and set of brake/gas pedals that had come with a video game driving simulator, and we set those up on a table for pretend driving play. (Also on the table we put laminated photos of “view out the windshield” with views of ocean, woods, snowy roads, the moon, and more to enhance their imaginary play.) We have a large rug with a road drawn on it, so we put out more cars for them to drive around.


We also put out one of these two Duplo car projects: the Duplo car launcher, and the Measuring Car. Some children would take apart the Duplo project and re-build it. Some just play with the assembled kit.

IMG_20160802_213004354_HDR IMG_20160802_173643474_HDR

Snack: Our snack volunteer brought in a great creative snack! Apple slice cars with grapes for wheels – check out the photo at the top of this post.

Circle Time:

Illustrating the concept: I made up posters, one titled “A Car is a Complex Machine – made up of lots of simple machines” and the other “Simple Machines that are Used with Cars, Trucks, and Buses.” I have photos of a number of examples, and next to each one, a diagram of the simple machine it represents. You can see a sample poster here… note that I do not hold copyright to any of the images used here and am not authorized to distribute this poster… but you could make your own!

Books: I didn’t find any books that were specifically about the relationship between cars and simple machines, but there are lots of great car books. In our opening circle, we read “If I Built a Car” by van Dusen. This is a very fun read-aloud fantasy about a child designing and building a fabulous car: “I’ll show you inside. I’ve put in a couch. It’s comfy and wide. Plus a fireplace, fish tank, and here’s something cool – The floor can slide open, and look – there’s a pool!” Wonderfully retro styling on the car, with chrome and fins.


Other nice book options: “Pete the Cat: The Wheels on the Bus“, because who can resist such a great combination? I would highly recommend Going Places, described in my Books about Inventors recommendations. A good option for toddlers is My Car by Byron Barton and for preschoolers, check out Cool Cars by Mitton and Parker and Cars Galore by Stein, Four to five year olds like Richard Scarry’s Cars and Trucks and Things That Go.

For awareness of other cultures, read Galimoto by Williams and Stock, which tells the story of a young boy in Malawi Africa, who wants to build a galimoto – a word that means car, but it’s also the name of push-toys made by children. The boy has a box with all of his worldly possessions – a ball of plastic bags tied with strings, a knife made from a tin can, and a puppet made from cornstalks. He has a few pieces of wire. Throughout the story, he scavenges, scrounges, and trades for other small bits and snippets of wire till he has enough to make a wire toy car to race with his friends.

Closing circle time – the Drive-In Movie. All the kids brought their cardboard cars over to circle time, and we watched a movie. I had edited down 12 minute versions of each of these, so we could watch the whole thing. The little kids watched Sid the Science Kid episode #125, “Climb Ignatz”, which is a review of simple machines. The big kids watched Bill Nye the Science Guy’s Simple Machines episode.

Resource: There’s a great list of links to more ideas on teaching simple machines to kids, and especially on teaching how cars and simple machines are related, at:

Note: All the activities described in my posts are from Family Inventor’s Lab, a parent-child cooperative class in Bellevue, WA. We are a play-based, STEM focused class for preschool through early elementary (kids age 3 – 7). We do a wide variety of fun, hands-on activities to learn about Science, Tools, Engineering, Nature, and Art. We also sing songs and read stories. Most of our activities are cheap, easy, and use everyday materials that most families would have in their homes (or their recycle bins!), so our activities are appropriate for classroom teachers, parents who homeschool, or after school programs.


  1. […] We build this car in our Engineering Unit when we study wheels and axles as a simple machine. I’ve been working for years to find a workable design for a car model that is do-able for little kids and has accessible, affordable supplies. Learn more about my past design process here. Here’s our Cars Lesson Plan. […]


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