Simple Machines – Engineering for Kids


We began our year with a unit on Simple Machines. Our goal is to introduce the basic concepts, give them lots of hands-on exploration of the principles, and encourage them to look for simple machines in their world.

Big Idea about Simple Machines

A simple machine is a machine with few moving parts, or no moving parts.

The big idea behind simple machines is they make it easier to do work. (They may reduce the amount of work it takes, or they may change the direction of the force you apply – which can make it feel easier to do the work.) But the more inspiring way to describe this to a young child is to say something like “do you wish you could lift heavy things like mommy/daddy does? Simple machines can help you do that. Doing things the smart way makes you stronger.”

This post includes resources that are helpful for a full unit on Simple Machines. To see lesson plans for activities and circle time demonstrations / books for each individual machine, click here: Inclined Planes, Pulleys, Wedges, Levers, Screws, Wheels & Axles

What is force? What is work?

In scientific terms, work is using a force to move an object. If you use force and nothing moves (like if you pushed on a brick wall), that’s not work. Pushing, pulling, and lifting are all “work.”

Note: although we didn’t do it in our class, it could be a good idea to first introduce the idea of “force” and how to measure how much work it takes to do something. Some books about force I would recommend are Forces Make Things Move, And Everyone Shouted, “Pull!”, and Move It!: Motion, Forces and You. (Note: Amazon says Forces Make Things Move is for ages 4 – 8, but I think there are far too many words for us to use it in a groups circle in a classroom setting with this age group.) Here are some additional ideas for how to teach about force, from Mrs. MyersTeach Junkie and iijuan12.

Books about Simple Machines

There are LOTS of books on simple machines, so many that I have a separate post all about Simple Machine Books. Check it out for details on them all.

I get all my class books from the library, so I get lots. If I had to buy on a limited budget, my top choices for my class of 3 – 6 year olds would be: How Do You Lift a Lion? by Wells, Move It! Work It! by Salas, the Simple Machines to the Rescue series by Schuh (note: this is the series with titles including the word “vs.” such as Raising a Bag of Toys: Pulley vs. Inclined Plane, NOT the series by Dahl with titles like “Levers to the Rescue” – that series is fine, but I’m not a big fan) and maybe the How Toys Work series by Smith.

For 6 – 9 year olds, I’d opt for Simple Machines series by Armentrout or Simple Machines by Tieck. Again, check out the other post for all the details.

Songs about Simple Machines

In our class, we’re using Simple Machines by David Newman: find the song and lyrics here:

Other options are:

  • Move It Work It from Capstone kids (see companion book above) which is to the tune of Kookaburra. Find the song here.
  • the Simple Machines song from Hubpages unit on simple machines. It’s done to the tune of Yankee Doodle. Find it here.

Videos about Simple Machines

Note: some parents prefer not to expose their kids to screen time – if that’s you, then skip the recommendations on videos and apps. There’s nothing your child can learn from them that they can’t learn from books, discussions, and hands-on experiences.

I like videos that can display simple machines in action, and describe the concepts while you’re viewing an example. There are several good ones on individual machines – just search YouTube. Here are my favorite overviews.

  • Bill Nye the Science Guy – Simple Machines   Best for ages 5 – 10, although my guy has liked Bill since he was 3. About 20 minutes long.
  • Sid the Science Kid. They did a fabulous series on simple machines. Sid is aimed at preschoolers and is set at a preschool, so very appealing and easy to understand for a 3 – 6 year old. There’s The Broken Wheel (Wheels & Axles); My Slide (Inclined Plane), Sid’s Amazing Invention (Lever), the Tree House (Pulleys) and Climb, Ignatz (summary of the series.) They’re available streaming on Netflix, or can be rented on Amazon (they’re listed under season 2 of Sid.) Each episode is 23 minutes, although some of that is filler (theme songs, etc.) that we tend to skip past.
  • Physical Science for Children: All About Simple Machines. 20 minute overview.
  • This is a nice 3-minute summary for adults about the concept, but it goes by too fast for young kids:

Games and Apps:

There’s a couple of online computer games you could play with your child that teach about simple machines.
  • “Twitch” is a fun online game, but you’d need to play with them and narrate their way through it to help them understand it better.
  • is also a fun online game. Best used as a review, after your child has learned all about Simple Machines.
  • There is an app called Simple Machines on ITunes, but I have not played it.
  • I like the app “Pettson’s Inventions“, available on Android, Kindle, and ITunes. The same folks also do Inventioneers, which is free and a little easier to play. In both, you assemble Rube Goldberg type devices to do simple tasks – you drop an apple on the character’s head, he turns on his blower, which turns a fan, which moves a gear, which knocks the basketball off the platform onto the seesaw and into the basket. You usually don’t get the answer right on the first try – you set up part of the process, press play to test it, adjust it, test it again, set up the next part of the process, test that, adjust it, and so on. Talk it all through with your child. Tell them what you’re trying and why. Ask them why something didn’t work and what you can do differently. It’s definitely a learning process which requires lots of tinkering.. A 6 or 7 year old might be able to play it alone if you play the first few levels with them to give them the basic concept. With a 4 or 5 year old you’d need to play it all the way through with them once, then they could probably do it on their own.
Here are my posts including activities and curricular ideas for each of the individual machines: Inclined Planes, Pulleys, Wedges, Levers, Screws, Wheels & Axles

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 that our activities are appropriate for classroom teachers, parents who homeschool, or after school programs.

Build a Clothespin Racer – Engineering for Kids


In class, we built two variations on “Cars that Move.” The Retractable Badge car is a little more of an engineering project that kids might learn more from. This one is easier to build, and a quick route to a satisfying toy.

Materials: ClothespinsPull Back & Let Go Racer Cars (note: If you only want a few of these and you don’t want to buy in bulk, I have seen the same cars sold 4 for a $1.00 at dollar stores), rubber bands, plastic straws and tape.

Prep: Cut plastic straw into 3/4″ lengths – these are about the same width as the front axle of your car. Then make a lengthwise cut in each one – you’re making a “sleeve” to fit the axle into. Note: To see a larger version of any image, just click on the picture.



Step One: Disassemble the car – pull the top off, carefully take the two halves apart, then take the front axle out of its plastic frame.

img_20161024_214938125  img_20161024_215231608

Step Two: Slip the front axle and wheels into the plastic straw. Tape the straw to the clothespin, right on top of the metal clip that holds the spring in place.

img_20161024_215509246 img_20161024_215603788

Step Three: Insert the rear wheel mechanism into the back end of the clothespin.


Step Four: Slip a rubber band on lengthwise to hold the rear wheels in place. OR use electrical tape to tape the back end and the front end – tape it tight so the tape offers a little tension. (Electrical tape works best, as it has just a little stretch / flexibility.)

Clothespin Pull-Back Racer Car - an Engineering Project for Kids DIY Clothespin Pull-Back Racer Car - Engineering Project for Kids from Inventors of Tomorrow

Step Five: Try it out! Set it down, pull it back, release – it should travel several feet. Note: if you’ve used a rubber band to attach them, the rear wheels often slip slightly out of place when you run the car, so just check and re-align with the rubber band before each run.

Variation: Instead of using the straw as a casing for the front axle, with a little more prep work, you can file a groove in the clothespin (right in front of where the groove for the spring is), then place the axle directly in the groove (without a straw) and cover that with a bit of paper or folded tape to create the channel, then tape that in place to hold the front wheels in.


Decorating your Racer: Kids can write their names on their clothespin, or can decorate them. You could use regular markers or Sharpies, but my favorite thing for decorating wood is these washable Chalk Markers. They’re actually designed to use on chalk boards or glass, and warn you not to use them on porous surfaces like wood (because they won’t wash off), but I like the results we get using them on wood.

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 that our activities are appropriate for classroom teachers, parents who homeschool, or after school programs.

Building a Car that Moves – Engineering for Kids


In last year’s Car-themed class, our students decorated toy cars. This year, I wanted them to BUILD a model car that moved. (Here are the design options we considered, along with source citations.) At bare minimum, I wanted cars that would roll down a ramp. But, even better, I wanted to motorize the cars – build something that would move on its own.

After LOTS of research, tinkering, contemplating, and starting over, we came up with two very different designs that we’ll be using in this weekend’s class. Here’s a “how-to” tutorial on our retractable badge car. Check out the clothespin racer here.

These cars are designed to be done by children as young as 3 years old (with lots of adult support). A 6 – 7 year old should be able to assemble a car with minimal support.

Retractable Badge Car

Note: to see a larger version of any photo, just click on it.

Materials : corrugated plastic or cardboard for car body; plastic straws for axle bearings, 1/4″ dowels for axles, wooden wheels, glue gun and/or Tacky Glue, and Retractable Badge Holders. (Note: the badge holders I link to there are cheap… but 4 out of 12 broke the first time we pulled the string out…. So, if you order, order more than you need!)

Preparation (Parent or Teacher):

Step One: Use pliers to take the plastic badge holder with the snaps off of the retractable clip. Caution: Do NOT cut off the plastic doo-dad on the end of the string! If you do, the string will retract completely into the badge, never to be seen again.

Step Two: Cut out the car body. It should be 5″ wide, and 7 1/2″ long. Cut out the tab as shown in illustration. (Or print this PDF to use as a template.)


Step Three: Cut dowel in half – making two 6″ segments.

Step Four: Cut straw – you’ll need two 1-inch segments, and one 4 or 5-inch segment.

Step Five: Use hot glue gun to drizzle glue on the edges of the wheels… this is to give them traction. Without it, the wooden wheels just slip and the car won’t move. Alternate: you can also wrap rubber bands around the rim of the tire. Or steal rubber tires off a toy.


Assembly by the kids:

Step One: Decorate the car body if you choose to. If you’re using corrugated plastic, you’ll need to use Sharpies or Sharpie Paint Markers. These look good, but are, of course, not washable. I paid the penalty this week, because the one kid who got marker all over their clothes in my class was of course my own kid!

Step Two: Clip the badge holder to the front of the car, so the clip is on top, and the holder on the bottom.


Step Three: On the bottom of the body, on the back end, tape two 1-inch segments of plastic straws to each side of the gap. It’s important these be straight / lined up with each other so the axle will run straight. Tape a 4 or 5-inch segment of straw straight across the front end of the car, just below the badge. (Adult should check for straightness.)


Step Four: Slide the wooden dowels through the straws.

Step Five: Put the wheels on. If they fit tightly and don’t slip around on the dowel, it’s best not to glue, so you can take it apart later if you want / need to. But, if they slip around on the dowel, you have to glue them in place so that when the axle turns, the wheels turn – otherwise this car won’t work. Use the Tacky Glue for this.


Step Six: Pull out the string for the badge holder and tie it around the axle. An adult will need to do this – it’s pretty hard to tie a string snugly, especially when it’s trying to retract into its holder. Then tape the plastic doodad at the end of the string onto the axle – this will help the string not just spin round and round when we want it to turn the axle.


Step Seven: Test it! Turn the car over – while pressing down just a but, pull it back about 10 – 15 inches  to wind the cord. Release. It will travel forward! (A little less distance than the length of the cord.) Check out the video below.

Taking the Retractable Badge Car to the Next Level

If you put bigger wheels on the badge car, it will go MUCH further. Try gluing CD’s on top of the wooden wheels (make sure they’re centered!) and check out what happens!

CD’s aren’t the perfect wheel… they don’t have any traction, so you can’t “pull-back” the car to wind it up. You have to hand wind the string, then set it down and release. You might also try some other kind of large wheel – such as wheels cut from a cardboard box.

Obviously, if you’d rather just start with the large wheel, you might not need to purchase the little wooden wheels – you could start with figuring out how to affix the big wheel directly to the dowel.

Have fun playing with cars!

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.

Wheels and Axles – Simple Machines Activities for Kids


During our Simple Machines unit, our final unit was on Wheels and Axles.

Free play: We pulled out our whole collection of toy trains and wooden tracks, and let them assemble tracks that trailed all over the room. (You could also put out cars and car tracks.) Some kids (generally boys) will gravitate to this activity and stay there the whole class…)

We got these great wheels that can be attached to any cardboard box. They’re really well built and easy for a small child to use. And any time you’re done with a box creation, you can take off the wheels and save them for the next time. We had one box with wheels, and one box that was the same size without wheels. Kids could load them up and see which one was easier to move.


We also had wooden dowels, and a basket – kids could load up the basket and roll it back and forth on the dowels.

Building: LOTS of building toys include ways to make wheels and axles: Duplos/Legos, Tinkertoys, K’NEX, and so on. Put these out for free play.

Observation: Encourage children to find all the wheels they can in and about the classroom (toy cars and trains, trikes, bikes, door knobs, and so on.) Encourage them to notice how the wheels work. One thing to notice is that with some things, the axle is fixed to the wheels and rotates with the wheels. But, in other cases, the axle is stationary and the wheels rotate around it (e.g. a skateboard).

Exploration: This post focuses on showing the difference between how balls roll and how wheels roll by making a set up wheels and axle from a Styrofoam ball:

Product-based art – Spinners: We made game spinners. We punched a hole through the center of  paper plates, and a hole in the center of popsicle sticks. Kids decorated the plates however they wanted to. We took a brad (paper fastener), threaded it through the stick, then a washer, then the plate. We spread out the arms of the brad on the other side of the plate, and taped them in place. Poof – it’s a spinner. (The stick is the “wheel” rotating on the brad axle.)



Craft – Tops. We made tops with dowels and wooden circles. If you don’t have wooden disks, you could use cardboard. Kids could decorate if they chose, and then play with for as long as they wanted to. (I have to be honest… I’m not sure if tops count as simple machines – are they wheels on axles? screws? neither?)


Craft – Pinwheels. Last year, we made pinwheels – learn about them here.

Art – Paint with wheels! You could use paint rollers, or a massage tool on wheels, or toy cars, or toy trains to paint with.

Gears – this is also a great opportunity to bring in gears… We’ll use the ones from a Delta Science Modules kit we inherited.


Building Sets: Some fun gear building sets include Gears! Gears! Gears!Quercetti Kaleido Gears and Gearation Refrigerator Magnets.

marbleocitySkate Park: Fat Brain Toys sells this great Marbleocity “Skate Park.” This kit is definitely something that an adult needs to build (or a patient and cautious older kid.) But, once it’s built, it’s very cool for kids to play with – they turn the crank, which turns the gears, which launches the ball. If kids are careful, it’s fine. However, they NEED to be taught what to do if it jams. If a marble jams just a bit, they need to back it up (i.e. turn the crank a little the other way) to unjam it, then move it forward. If they try to force it forward, it WILL break the crank. As we learned at the beginning of our morning class, when one of our older and pretty careful kids was playing with this. I’ve repaired it now, and will use it next year as a demo where we can show kids how to handle jams carefully. The one thing I wish were different about this kit… it does not use standard size marbles, but instead uses specialized mini marbles. I’m hoping it’s possible to find replacement marbles somewhere if needed, but I haven’t found them yet.

Toy: We also put out this cool Duplo top launcher, already assembled, plus dirIMG_20160802_173512786ections on how to build it, so kids had the option of taking it apart and re-building it. (None took that option.) This is a REALLY cool toy. But, the motor skills required to launch a top were more than any of our 5 and under kids could really manage.

Water table and sensory table: We have water wheels they were able to play with. It would be really cool to build your own water wheels. Here’s ideas on how to do it:

Song: The Wheels on the Bus, of course! Another option is Bumping Up and Down in My Little Red Wagon, which includes the words “One wheel’s off and the axle’s broken.”

Books: We had several books from series about Simple Machines. We read in circle Pete the Cat: The Wheels on the Bus by Dean and Going Places by Reynolds.

Outdoor time: Bikes, Trikes, and Wagons, oh my!

For a wheels theme, you could obviously do LOTS of activities related to cars. We did a whole week just focused on cars as a complex machine. You could use almost any of these car ideas in a session on wheels.

There’s lots of other great ideas for wheels and axles activities here:

Key concepts of wheels and axles:

When you try to push a load across the ground, there’s a lot of friction that makes it hard to move. The whole surface area of the load is on the ground. When you put the load on wheels, then there’s only friction on the very small part of the wheel that is touching the ground at any given time. Thus, it’s much easier to move a heavy load over a long distance.

A demonstration for Circle Time:

We loaded up a basket with bags of dried beans for weight. We had our 8 year old teaching assistant push it across the ground. Then we showed everyone the rough surface on the bottom of the basket. Then we showed them the smooth bottom of a cardboard box. We placed the basket in the box, and pushed it across the ground. Much easier! Then we talked about friction.

After that, we laid out several short lengths of PVC pipe on the ground and put our box on top of them and showed how much easier it was to move the box back and forth. (Just roll a very short distance back and forth.

Image result for egyptian logs move rocksWe talked about the idea that ancient Egyptians may have used a similar method to move the large stone blocks used to construct the pyramids, and showed them a picture of this process.

We then tried to move the box a long distance on the dowels. The kids discovered that as you do this, the load rolls off of the dowels, and you have to move that lost dowel back to the front of the row over and over.

(Note: I got this demo idea from Little Blast blog, but we worked on a carpeted floor instead of hardwood, so there’s lots of friction. We used a basket instead of a smooth box – again, this increases the friction so better illustrates the benefit of the dowels. There’s also a nice post here on using a brick and pencils to illustrate this concept.)

One child got the idea of taping the pipes to the bottom of the box. We did, to show why this doesn’t work. (The pipe wheels no longer rotate.)

Then we taught the idea of wheels and axles, and mounting the load on a set of wheels and axles. There’s lots of ways you could do this… We used the wagon from our Simple Machines Set, but you could use any car or wagon to show what wheels and axles are.

Then we placed our basket of beans in a box with wheels on it (see above) and had our assistant pull it all around the room to show how much easier that is to move.

Here’s another great idea for a demo: put a grown-up on a board. Put the board on two scooters or skateboards and push the grown-up around.

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 that our activities are appropriate for classroom teachers, parents who homeschool, or after school programs.

Designing a Car Project – Preschool STEM class

Cars Craft Project for Kids

painted cars.pngLast year, when we studied Cars, our lead teacher found wooden cars with turning wheels that kids could paint. This was a fun and easy art project, but at $2 per car, it was pricier than most of what we do. And, it was just an art project. We also decorated big cardboard boxes into cars we could use for a “drive-in movie.” It’s a very fun art project…

I decided that this year I wanted to do an Engineering project, where the kids BUILD a car that rolls.

I’m going to share my design process in the top half of the post for those who enjoy seeing the steps in the process. If you just want some conclusions, skip to the bottom of the post.

Criteria: Our students range in age from 3 – 7. I was looking for a project that our 5 – 7 year olds could do independently, with assistance with perhaps just a couple quick tasks. I expected our 3 and 4 year olds would need a fair amount of help from their parents or a teacher. The materials need to be affordable. As a non-profit that tries to keep our tuition low, it’s something I keep in mind. We do like to use items from the recycle bin when possible, but we also have to consider whether we can get enough of them for 28 kids to do a project. (So, when we’re talking wheels for cars, that means 112 items!) It couldn’t involve a crazy amount of prep work for my co-teacher and I. (So, not cutting out 112 circles…) And it had to produce a fun and useable product that was not too delicate to be played with.

Gathering Ideas

I turned to the internet for initial ideas. Here’s what I found. (Note: some of these cars are “motorized” and given mechanisms that help them move independently. I’ll write about that in a separate post – this is just about building the body and wheels of a car that can roll down a ramp.)

clothespincarAlmost Unschoolers – Body: clothespin; axle and wheel: Straw casing, bread tie and button wheels. Assemble: run bread tie through straw, loop bread tie through holes in buttons or the loop on the back of the buttons; Clip clothespin over one straw, slide the other straw in the back, add tape so it can’t slip out. My thoughts: minimal prep, looks doable for little ones… would buttons roll well? Could I sub pipe cleaner for bread tie? Price of buttons?? Price of clothespins?

sailcarNerdy Science – Body: TP tube. Axle and wheel: BBQ skewer and circles cut from cardboard (kleenex box). Assembly: holepunch the TP tube and wheels. Run skewer through, tape wheels in place on the skewer.   (Optional: add sail). My thoughts: easy to assemble, cheap materials. Lots of prep time cutting circles. Not very durable for playing with, and how well do wheels roll? Guessing it won’t roll down a ramp on its own.


Make it @ the Library – Body: paper towel tube. Axles: pencils. Wheels: cardboard circles in the front, CD’s with taped wheel hubs in the back. Assembly: Punch holes in tube for axles. Put pencil through front holes, add cardboard wheels. Put pencil through the back, wrap tape around enough times to fill the holes on the CD, mount the CD wheels. My thoughts: get pencils from the dollar store to make them affordable. Source for CDs? (I know I can get 100 brand new blank CD’s for $16. But that seems wrong somehow… I’d rather get some from somewhere that was disposing of old used CD’s.) Cutting out front wheels = lots of prep work! Pretty doable, though wrapping the tape might be a challenge. [Can be motorized with rubber bands.]

raftRAFT (Resource Area for Teaching) – Rolling Explorations. Body: foam core board (or cardboard or corrugated plastic). Wheels / axles: straw casing, BBQ skewer axle, CD wheels. Wheel hubs made of cardboard – glue to the CD so there are smaller holes in the CD to run the skewers through. Assemble: tape straws to body. Run skewers through straw and wheels. Thoughts: easy to assemble. Lots of prep time cutting bodies and wheel hubs. Would need to have lots of CDs! (Could be motorized with a mouse trap.)

raft2RAFT – Car on a Roll. Body: corrugated plastic or cardboard. W&A: Straw casing, coffee stirrer, foam wheels. Assemble: tape straws on, run coffee stirrer through straw, mount foam wheels. Thoughts: Easy! Where do I get foam wheels??
(Note: you can buy kits, $12.99 for 10 cars:

raft3RAFT – Cart the Box. Body: cardboard box or lid (width needs to be less than skewer length). Axles: bamboo skewers, wheels: CDs; Assembly – glue foam blocks over holes in CD. Put skewers through box, then through straw spacers, then into the foam blocks in the CD. Thoughts: need to collect boxes / lid; prep foam blocks (or other wheel hub), buy lots of CD’s; side benefit – box can carry a load.raft4

RAFT – Fender Bender Boxcars. Body – use a rectangle of stiff paper, make four cuts, bend flaps up and tape to make a box. Wheel and axles: tape straws on bottom, thread smaller straws through them, attach to plastic wheels. Thoughts: Easy. flimsy?? What to use for wheels….

filefolderRAFT – File Folder Retractor Car. Body – fold and assemble a hanging file folder in complicated ways. (I confess, I skimmed the directions, and it just seemed complicated.) Axles – bamboo skewers. Wheels: CDs, with hubs made of tightly wrapped paper – again too complicated for little kids to make.) (Can be motorized with retractable badge.]

retractorRAFT – Retractor Car. Body – Corrugated cardboard. Axles – bamboo skewers run through the channels in the corrugated cardboard, with wire nuts / plastic cones. Wheels – plastic or paper cup lids with foam circle hubs. Assembly: Run skewers through cardboard channels. Cap off each skewer with a wire nut. Poke holes in foam circles, stick to lids, mount on skewers. Thoughts: source for lids? for foam circles? Cost of wire nuts? (Can be motorized with retractable badge.) RAFT sells kits for these – $30 for supplies for 10 cars:

A couple other ideas – the sources didn’t have pictures….

  • put coffee stirrer straws inside a regular straw; get bottle caps, drill holes in center, and thread coffee stirrer through hole… thoughts – would need to collect bottle caps
  • Could order wooden wheels and 1/4 dowels from Amazon. Easy! But not materials parents would have easy access to at home, plus cost ~ $1.60 per car.
  • I also tested plastic bobbins (no traction!) and wooden spools (lacked traction and each bag of spools only had a few the right size to mount on a wooden dowel.)
  • I also found these plastic pulley wheels on Amazon that I want to test. Good news: 30 pieces for $2.52! Bad news: I ordered them October 10, and they’re not expected to arrive till November 15.

Summary of options found:

Body = clothespin, TP roll, paper towel roll, flat piece of cardboard / foam core / corrugated plastic; box, or paper folded into box. I knew I wanted to build a car that was capable of using a retractable badge clip for a motor, so I needed a sturdy body to withstand that.

Wheels = buttons, paper circles (lots of prep!), CD’s (where to get, plus challenge of making hole smaller to mount on a skewer or dowel), wooden wheels, foam circles (where to get other than with RAFT kits?), cup lids, bottle lids, spools, bobbins. Again, if I wanted to motorize the car, I’d need wheels with traction. And, I needed minimal prep time.

Axles = bread tie inside straw, pipe cleaner inside straw, BBQ skewer through holes in toilet paper tube or box, skewer through straw, dowel, coffee stirrer in straw, run skewer or dowel through the channels in corrugated plastic or cardboard. Note: I tested pipe cleaner axles, and I found that every time I tried to bend them to attach to a wheel, it would bend the center section and they wouldn’t roll smoothly.

“Motors” – mousetrap, retractable badge, mechanism from pull-back car, rubber bands.

Simplest Option

If you’re looking for a simple art project that preschool age kids can do, then I would either:

  • Start with the Nerdy Science idea: kids decorate TP tubes, you punch four holes in each, run skewers through, then you mount on cardboard circles. (If you’re lucky, you have a die cut machine to prep these!) Not terribly durable, but easy and cheap.
  • Use small boxes for the bodies (or fold your own like Fender Bender boxcars), tape straws to the bottom to serve as “bearings” for the axles. Use smaller straws or skewers for the axles. Attach to buttons or cardboard circles.

I wanted to be able to motorize our cars, so neither of these options was sturdy enough for me. I did lots of testing, revising, re-building… tinkering… I ended up with two options I’m considering for this weekend’s class.

Our Final Projects

  • Using a clothespin body like Almost Unschoolers. Dismembering a pullback car to use for the wheels, axles, and motor. Tutorial here.
  • A design inspired by several of the RAFT ideas: I’m using corrugated plastic for the body (cardboard would also work), straws for bearings, dowels for axles, and wooden wheels. We’ll motorize it with a retractable kit. Tutorial here.

Tinkering Method You could also do this as a pure tinkering activity – on a table, put one bin full of options for car bodies, a bin full of options for wheels, another container with possible axles, and let the all be creative, building cars from scratch.

Testing Your Cars

Once the kids have build their cars, set up a test track… a nice long ramp and measuring tape so they can measure how far their car travels.

After testing, you may need to “tinker” – adjust variables to help the cars roll better.

Really lightweight cars often don’t roll well. Adding a little weight can help. Depending on your design, you could place weights in your car (like pennies, glass blobs, washers…), tape or glue them on, or clip on big binder clips or paper clips.

Traction can be a big problem. If there’s too much friction, your car won’t roll (so rough-edged cardboard wheels might have problems. Can you smooth them?) If there’s not enough friction, the car might skid down the hill, but it won’t roll. (Can you add traction to your wheels? Or add friction to the surface… cars might roll better on fabric or sandpaper than they do on smooth wood, metal, or cardboard.)

What’s your favorite car design for kids?

Screws – Simple Machines Activities for Kids

Screws - Simple Machines Activities for Kids age 3 - 7During our Simple Machines unit, we learned about screws.

Key concepts of screws – How to Demonstrate and How to Help Kids Experience

  1. A screw is an inclined plane (ramp) wrapped around a central rod.
    1. To illustrate: Show a picture of a very long highway ramp or very long staircase. Talk about how it might be impractical to have such a long ramp, so sometimes they wrap this into a screw shape – show a picture of a spiral parking garage (like at Sea-Tac airport) or a spiral staircase. (Here’s a PDF of the photos I found as an example. I don’t have copyright permission on these, so you should find your own.)wpid-img_20151010_095549692.jpg
    2. Another illustration: Find a picture of a very steep path up a mountain (an inclined plane) and a switchback path (similar to a screw). By wrapping the path back and forth and back and forth, it’s more climbable.
    3. Activity for the kids to experience this concept: cut a triangle of paper. Mark the “ramp” side of the triangle. Roll the paper up around a pencil, and it becomes a screw. (Note: you could use these papers to make paper beads for a necklace.) Also, see snack ideas below.)
  2. A screw takes rotational motion and turns it into vertical motion. When you turn a screw, it moves down or up, depending on which way you turn.
    1. To demonstrate / let kids experience it: take a very long bolt. Spin a nut around it. You can see that the nut travels up and down the bolt. You can give kids a dish of nuts and bolts and have them play with this.
    2. See the toy drill set described below.
    3. Alternate demo / experience: Take a peanut butter jar (or similar jar), and screw the lid on – pointing out how it travels downward, then unscrew it, pointing out how it travels upward. Give children jars and lids to try this out.
  3. Screws hold things together.
    1. To demo: use two boards – hammer a nail through them to attach them. Then pull them apart. Then attach them with a screw. Show how you can no longer pull them apart. (Note: as always, test your demo before class to make sure that it works well with the exact materials you will be using!)
    2. Kids’ experience: See workbench idea below.
  4. A screw can also be used to move things..
    1. Possible illustrations: an Archimedes screw can lift water up hill – one of the earliest water “pump” mechanisms. A grain auger is used to lift grain from trucks into grain silos. When you drill a hole, the drill lifts the cut wood up and out of the hole.
    2. To demo / let kids experience: Use the Archimedes screw or grain auger described below.


Bolts: We had a big bin of these building toys in the classroom – I unfortunately don’t know what they’re called! But, they’re big screws and bolts and plates and cubes and wheels to attach together with the bolts.


Drill: This toy drill set has a battery operated drill driver that allows kids to screw bolts into the board, then reverse direction and pull them back out. Very popular with lots of kids.


Workbench: You could offer boards, screws, and screwdrivers, and let children screw real screws into real boards. (You might need to use a nail to make some pilot holes to get screws started into the wood.) I think this is totally reasonable for kids age 5 and up. For kids 3 to 5, you have to use your judgment. I would do it if I were working one-on-one or in a small group of kids. But in our larger class, we used toy hammers and golf tee “nails”, plastic drywall screws or non-pokey screws and a screwdriver.

If possible: put out some screws with wide threads and some with tight threads. They could see that wide threads take more effort to screw in. Tight threads mean less effort, but you have to rotate it many more times to move the same distance.

Archimedes screw:

Our Simple Machines Activity Set came with a small Archimedes screw. It works really well with a wide variety of materials – I’ve used it with M&M’s, rice, corn meal, and others. I like split peas / lentils best, as they move through it well and are easily cleaned up. In this video, I use water beads, because they’re what I had handy, but I wouldn’t use them in a kids’ activity, because if you’re not careful, the screw will break them up into little bits. I also like this because it’s REALLY easy to clean.

img_20161022_121428967I also found this great toy Grain Auger. It’s really cool and easy for kids to use. BUT it doesn’t work with a wide variety of sensory items. Bigger items jam it, and if kids are careful, they can back it up and unjam it, but most kids just crank it hard in the same direction to try to undo a jam, and I suspect that would break it. Also, in order to clean it, you’ll have to use a screwdriver to completely dismantle it – I haven’t attempted this yet. For class, we used it with cornmeal8480455732_c8f2d2cff7_z. We just put in some containers to fill. Next year, I want to put in a tall cylinder (maybe an oatmeal container) that would be similar to a grain silo, and then post a photo of a real grain auger and silo.


Snack: You could use refrigerated crescent rolls – they come out of the pack as triangles (inclined planes), and you roll them up into screws. You could also make pigs-in-a-blanket, and wrap the ramp (crescent roll) around the rod (hot dog).7

You could also use an Apple Peeler / Corer. These basically involve mounting an apple on the end of a screw, and as you turn it around and around, the screw pushes the apple forward into a blade, peeling it, coring it, and slicing all in one move.

Take Home Challenge: Make your own Archimedes screw: Here are a few possible ways to do that:

Using paper and a plastic bottle: See directions here: and an example here:

Wrapping tubing around a stick or pipe. As in this video: or as shown here:

Here is a paper model of an Archimedes screw: They say it can be used to transport sugar.

Books: Check out my post on Simple Machines book series. I also just learned about a book called Drew the Screw which sounds great. The Amazon description says: “The pencil draws, the tape measures, the saw cuts and the drill makes holes.  Together with the boy, they are building a treehouse.  What can you do? the tools ask Drew. Drew worries that he can t do cool things like the other tools.  But when boy comes for him, Drew is surprised to get a job that’s not only important but just right.”

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 that our activities are appropriate for classroom teachers, parents who homeschool, or after school programs.

If I Built a House – Engineering for Kids

House Building Themed Activities for Kids

We continued our Engineering theme with a class about building houses.

Question of the Day: What are the steps in building a house?
Challenge: Can you build a house with friends?

Incorporating Books into the Lesson: We had three different books that are about the process of building a house.

  • Building a House by Barton is a nice simple book for ages 3 to 5 about each of the steps in building a house.
  • Building Our House by Bean is great for ages 4 to 6. It tells the story of a family building their own house. Told from the perspective of a young child.
  • How a House Is Built by Gibbons – I find some of the details in this book are more than a child age 5 – 8 would care about, but the illustrations are good.

We photocopied and printed copies of many of the pages, and posted those pictures near the activity related to that step in the book to help give context to the activities we were doing. We later used these books in circle time, where they wove together the story of the separate activities into a whole process. Here is a pdf of the pages from Barton.

Note: If you would like to have a full curriculum based on one book, I have an alternative lesson plan for building a house that is all tightly focused around the Barton book, with activities to match virtually every page. Check it out here.

Activities – Stages of House Construction

The Design Process – Blueprints (Crayon Resist Art). We set out white crayons and white oil pastels so they could draw floor plans or house designs or whatever they wanted, and then paint over them with thinned blue tempera paint and a roller brush. (Idea from No Time for Flashcards.) We put up pictures of blue prints from our books.

Excavation – the sensory table: One year, we had sand, buckets and shovels. This year, we put out brown cloud dough  – it looks like rich, brown dirt, but it’s made of flour, cocoa powder, and vegetable oil, so it smells good and is a good option for a sensory bin if you have little ones who might eat dirt. We put in a collection of toy bulldozers and dump trucks. We posted illustrations of bulldozers excavating house sites.

Framing – Build a House! This is one of my all-time favorite collaborative activities for kids age 3 – 7. I first saw it at a construction themed birthday party. (Read more here:

You use foam insulation panels (we use the 1 inch by 2 foot by 4 foot panels from Home Depot – for this class, I had nine full panels, plus a few cut into halves and thirds. Most were re-used from the last two times we did this project) plus golf tees and toy hammers to assemble a building. Kids LOVE to hammer and feel like they’re building “something real.” It can keep them entertained for hours. Here are some of the buildings my students have built. Click on any picture for a bigger view.

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You can use the panels horizontally – the advantage to that is kids can work more independently – or use them vertically to make a 4 foot tall building – the advantage is kids can stand up inside it, but they’ll need adults to help them put together the first few tall walls, and they’ll likely want to climb on chairs to do some of the work.

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One of the great things about this project is that it’s highly collaborative. It’s almost impossible to fit two panels together by yourself – you need someone to help hold it while you get those first few nails in. This leads to lots of good teamwork and negotiation as they agree on a plan.

Options: One time, we also gave them small pieces of Styrofoam to nail on as windows and other accessories. You could give them a Sharpie to draw decorations on the panels, but I want to be able to re-use them in future classes, so I don’t. Having tape would allow you to do some things like create hinges for doors, but it can be hard to remove the tape without tearing off the silvery covering.

This is a great activity for any preschool class or for a birthday party, and it’s pretty cheap – about $30 in Styrofoam, $4 in golf tees, and you can ask all the guests to bring their own toy hammer or mallet (just have a few extras just in case.) And when you’re done, you have insulation panels for a crawlspace or attic – with just a few holes in them :-).

Imaginative Play: Construction worker Dress Up.  We had construction helmets, safety vests, goggles, and a Home Depot tool apron, plus construction cones to set up around our “work site” to add to the fun of the day.

Masonry / Brick-Laying: We put up illustrations from the books of workers laying a brick foundation, and a drawing of a fireplace and chimney from the Barton book. We set out the Duplos. Kids could build whatever they wanted – a few tried the fireplace.

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Plumbing at the Water Table: We posted pictures from our books of plumbers putting in pipes. We used elements from our DIY water wall and Waterway Pipes last year. This year, we used 6 inch segments of PVC pipe and a variety of connectors. Plus a small pitcher / measuring cup for pouring water through the pipes.

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Wiring – With the book pages about electricians wiring the house, we set out directions and a map for a very simple circuit with a light and a switch. We used Snap Circuits. You could also use littleBits or just a battery and an LED light on wires. (Learn more about Snap Circuits and littleBits here.) See our Electricity lesson plan for ideas.

Paint A House. We took cereal boxes, cracker boxes, and Eggo boxes and turned them inside out so they were plain cardboard. (Tip: use a glue gun to re-glue the seams – faster and sturdier than tape!)  Then the kids painted them. You can use paint rollers Paint Rollers with watered down paint (so it’s not so gloppy and so it dries faster), or you can use 1 – 2″ wide paintbrushes like you’d use for detail work when painting a room. This year, our paint was taking forever to dry due to extremely humid weather, so we used paper towels to wipe the excess paint off the houses.


Add Roofs, Windows and Doors. After painting the cardboard houses, then they added paper roofs if they wanted, and glued on windows and doors. (We had found photos of windows and doors online, put them into a document and printed it out. We pre-cut some for the younger kids, but older kids practiced their scissor skills cutting these out.) [We got the idea for this from Learn with Play at Home.]

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Another option for painting a house: You could get a VERY big cardboard box, like a refrigerator box. Set it out on a big plastic tarp. Give the kids paint rollers and paint and let them get to work – this is a fun big motor activity.

Art Project – Paper Bag Houses. We got the idea from Kids Activities Blog, but we used white bags and markers and dot paints (bingo markers) instead of paint, so we didn’t have to wait for them to dry. You could also use stickers, as Inner Child Fun suggests.IMG_20160305_110308497

Take a white  paper bag, decorate it with windows, doors, and a roof. Open it up, put a little crumpled paper in the bottom to help it stand, fold over the top to close it, staple it if you’d like.

Build a Neighborhood. One year, we set up tabletop play – we covered a table in paper, drew roads on it, and added cars and paper bag houses. This year, we had a rug with a road on it, so as kids finisher their houses, they added them to the “neighborhood” on the rug. Driving cars around the town is guaranteed to appeal to some child in each class!

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Sorting Activity – Arranging the Furniture. Last year, we had a collection of old doll house furniture (mine from childhood, that my parents just rummaged out of their basement!). We labelled 5 pieces of paper to represent the rooms of the house and kids sorted the furniture into the appropriate room.

This year, we had a large printout of a house floor plan, and we gathered clip art pictures of furniture for kids to lay out in the house.

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Building Toy: We put out Lincoln Logs with a drawing of a log cabin.

Creation Station: We have an area in the corner with miscellaneous supplies for spontaneous creations. Last year, some of our students decided to build rooms with tables and chairs.


Snack: A great option would be simplified gingerbread houses: graham crackers, frosting “cement” and either candies or dried fruits for decorations.

Opening Circle

Gathering song – we start with a really easy song to get their attention focused. We used Rhythm Sticks and mimed each verse. We chose these verses because they taught the actions we would do in our other song.

This is the way we saw the wood, saw the wood, saw the wood,
This is the way we saw the wood, so early in the morning.
This is the way we hammer the nails… Lay the bricks… Paint the walls….

But, you could also do these verses to match the actions in the Barton book, in order.

This is the way we dig a hole… hammer and saw… pour cement… lay the bricks… make a floor… put up walls, build a roof… build a fireplace… put in pipes… wire for lights… put in doors… paint the walls… build a house. [on final verse, instead of ending with “so early in the morning” end with “the family moves inside.”]

Observations: Ask: What have you done so far? What do all those activities have in common? [answer: They are all steps we take while building a house.]

Overview of the Day’s Activities: Flip through the Barton book, pausing on each page to show the illustration, then point to / talk about the related activity, and/or comment on the children’s activities so far: “I saw X working on the pipes” or “Y, you had a lot of fun arranging the furniture, didn’t you?”

Book: Building Our House by Bean. This tells the story of a family building themselves a house. As you read through it, point out the signs of the seasons. They begin gathering supplies in one autumn, then stake out the location of the house in winter, begin to dig in spring, raise the walls in summer, roof in fall, finish the indoors in the winter and move into the house in the spring. The cat has kittens and the mom has a baby along the way! It’s told through the eyes of a child narrator, which helps to engage kids.

Closing Circle

Song – Hand out rhythm sticks, and reprise the song from opening circle.

Song: Then sing “When I build My House” by Parachute Express. (starred lines are done as call and response – you sing, they echo.) Mime the steps with rhythm sticks. I made posters of the lyrics that I printed on 11×17 paper.

When I build my house*, I’ll need some wood*.
And I’ll saw the wood*, when I build my house*.
And we’ll saw the wood, saw the wood, saw the wood when I build my house.
When I build my house, there’s so much to do…
It’s nice when you come along and help me too.

Sing again, but swap in… I’ll need some nails… hammer the nails. After singing third line with nails, repeat the third line with sawing the wood. Continue with Bricks, lay the bricks. Paint, paint the walls.

The song finishes with:
And when I’m through, I’ll go inside. And I’ll look with pride at the work I’ve done.
I painted the walls, painted the walls, painted the walls when I built my house.
Laid the bricks… Hammered the nails… Sawed the wood…
When I built my house, there was so much to do…
It’s nice when you come along and help me too.

Note: you could also do this song in opening circle, leaving off that last verse about “when I’m through”, and then do the song again in closing circle with all the verses.

Discussion: What was their favorite part of building a house – what activity was most interesting?

Book: If I Built a House, by Von Dusen. This is a FABULOUS book. It is a boy telling the story of the house he has designed. It’s got a great rhyming, rhythmic flow to it, fun retro illustrations, and wildly engaging concepts about the kinds of rooms the boy would build if he could. I especially like pages at the beginning and end where we see that he’s drawn a house plan and built models from Legos, tinker toys, paper towel rolls and cardboard.

Optional Imagination Activity: Give them paper to draw on. Encourage them to write or draw ideas for a house they would build. If they don’t want to write / draw, they can ask an adult to help. While they draw, put on music, do own sketches on board. After 5 minutes or so, ask some to share.

Other Books for the Bookshelf

  • Let’s Build by Fliess and Sakamoto. Story of a boy and his dad building a fort together. They grab a pencil, draw the plans, head for the hardware store, come home and get to work. It’s a sweet story with nice illustrations and rhyming text, and shows dad and child building together, with the child using a real hammer, helping hold the hammer, etc. Kids will like this book. Amazon reviews indicate adults can be troubled if they think about it too hard… the fact that Dad knocks out perfect architectural drawings, Dad and kid build a big playhouse with no additional help, and the fact that the entire project appears to go from idea to completion in one day seem dubious to adults.
  • Andrew Henry’s Meadow by Burns. Too long for circle – could be read-aloud at home to a 4 or 5 year old, or read by an older child. Andrew likes to invent things… but his family doesn’t appreciate his creations, so he runs away and builds his own house in the meadow, and then all the other quirky kids come to join him and he builds the perfect house for each. A treehouse for the birdwatcher, a house over the creek for the boy who loves to fish, a dugout for the lover of pet rodents, and so on.
  • Construction by Sutton and Lovelock. This is about building a library, not a house, but is again a great review of the process (excavation, foundation, framing, finishing) with an irresistible rollicking rhythm – great for age 3 – 4. “Rise the roof. Raise the roof. Drive the screws in now. Power tools will do the job. Ring! Zing! Pow!”
  • A House Is a House for Me is a nice rhyming read with good illustrations: “A hill is a house for an ant, an ant. A hive is a house for a bee. A hole is a house for a mole or a mouse. And a house is a house for me.” It goes on, eventually saying “And once you get started in thinking this way, It seems that whatever you see is either a house or it lives in a house.” Nice read-aloud from 1978.
  • The Little House – winner of the 1942 Caldecott medal, it tells the story of a little house outside of town that is eventually surrounded by the skyscrapers of the growing city.
  • Tap Tap Bang Bang. Nice for 3 – 4 year olds, telling of tools and the sounds they make
  • Houses and Homes – a simple non-fiction book about houses around the world.
  • The ABC Book of American Homes. Shows a wide variety of houses, from apartments to beach houses, from log cabins to Kilbourne houses from Sear and Roebuck, Quonset hut to RV. Nice illustrations and fun to flip through, but I don’t think the text would engage the average child.
  • From Mud Huts to Skyscrapers – a history of architecture, with lovely illustrations of most of the most famous buildings in the world. Aimed at 10 – 12 year olds, and more a reference book than a read-straight-through, but interesting for little ones to flip through to see how varied buildings can be.

This post contains Amazon affiliate links, which will take you to detailed descriptions and reviews of books and products. Many of the books may be available from your local library.

Supplementary Activities

Time Lapse Videos. Go to YouTube. Search for “build a house time lapse” videos and you’ll find plenty! You’ll have to explain to your child how a time lapse video is made, but after that, they can be fascinating to watch.

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 that our activities are appropriate for classroom teachers, parents who homeschool, or after school programs.