Tag Archives: tinker


Catapults are a huge hit with kids… being able to launch things into the air and across the room is always exciting!

There are LOTS of ideas online for how to build catapults. I want to present a simple series of catapults that show the evolution of an idea.

Supplies needed: pencil, popsicle / craft sticks, rubber bands, a plastic spoon, an object to launch (e.g. pompom or mini marshmallow or coins)

Stage 1

First, take a popsicle stick (the bar of your lever), balance it over a pencil (your fulcrum). Put an object (your load) onto the end that’s laying on the table. Hit the high end of the stick, the object launches. This is an easy depiction of the simple machine concept of levers (learn more about Levers here.)


You can also play with this idea – use a bigger fulcrum – use a longer lever. Like try a large spoon balanced over a rolling pin, or a ruler balanced over a marker.

Kids will have plenty of fun with this. Launching things is fun. But, they’ll soon discover that this is a weak catapult – we can get a lot better launch by evolving it.

Stage 2

Now, take two popsicle sticks: Use a rubber band to fasten them together at one end. Then slide a pencil (or three craft sticks bundled together) between the sticks until it pushes up against the rubber band. Set it down. Put your pompon (or coin) on the raised end, then use your finger to press down and release. The pom pom will fly much higher!


If the coin / pompom keeps sliding off the end of the bar, you can glue a lid to the end of the bar so you have a “bucket” to put your coin / pompom into.

Stage 3

After they’ve had a good time with this one, you can take this simple design to the next level by creating a spoon catapult. You’ve already got your two popsicle sticks banded together. Use a rubber band to attach a plastic spoon on one. (Here’s a picture from www.devincollier.com/how-to-build-a-simple-small-marshmallow-catapult/. to show you where to fasten it.)

Slide your pencil in between the sticks, as before (or use two or three popsicle sticks rubber-banded together). Now launch items from the spoon – your launch arm is longer, and you added the springiness of the spoon – does this increase the strength of the launch (i.e. does your object travel farther?)


Stage 4

Now bundle together 5 craft sticks to use as your fulcrum – this is what is shown in the picture above, and you can also find directions at http://cosmos.bgsu.edu/STEMinPark/takeHomeActivites/2012/MarshmallowCatapult.pdf

Is the catapult stronger with a taller fulcrum and more pressure on the rubber bands that bind the launch sticks together? What if you use 8 sticks in your bundled fulcrum?

Stage 5

Use longer bars to build the catapult than popsicle sticks. Maybe rulers? Rubber band them together at one end, and keep using your bundle of craft sticks as a fulcrum.

Continue to experiment… Here’s a very similar catapult built from a couple of wooden yardsticks, a piece of cork (used as fulcrum to separate the two sticks – you could use your stack of popsicle sticks) and some tape (could use rubber bands).


Testing and Tweaking

As you build a variety of catapults, test them. You can compare on two criteria: which designs launch the object the farthest and which launch it the most accurately (i.e. can you hit a target with it.)

For more STEM related activities, click on the word STEM in the right sidebar…

Building a Scarf Cannon

We’ve travelled to many children’s museums around the country, and our sons favorite exhibits are always the ones where fans or pneumatic tube systems shoot balls or scarves  through tubes, like the “scarf poof” at Kidsquest, the Air-mazing Laboratory at Imagine in Everett,  and this one at the Tacoma children’s museum:


We started with the fan. Exploratorium mentioned that they had made a wind tube using a squirrel cage fan. I researched those, but they need wiring skills I don’t have. So, we chose a utility fan, specifically the Lasko Blower. (You could probably use a regular fan, but it wouldn’t create nearly as strong a wind.) This video shows what the fan does with a scarf on its lowest setting – all the other videos have the fan on the highest setting. (In class, I started the kids with just the fan and some scarves to blow up into the air, and even that simple game elicited gleeful giggles.)

We bought a ten-foot long flexible ventilation hose The challenge was: how do we connect this round hose to the oblong opening on the fan?

We built a couple of boxes from cardboard and cut door flaps in them where you can push a scarf in. [Note: you can find a pattern for these boxes in a more recent post on my other blog.] These were more fun for kids, because it focuses the air, so scarves shoot a little higher.

And check out what happens when we sent a little plastic “bowling ball” through the door.

We mounted a poster tube through the box. You could stuff scarves into a tube, hold your hand over one end, then let go, and they’d shoot into the air. You could shoot a lightweight ball too – like a cannon ball.

Then it was time to figure out how to attach the hose to the box. We tried taping the hose to the box but that didn’t work. So, I bought a hose connector for the end of the hose, figuring we could attach that more easily. IMG_20150921_184333465

Then we assembled it. Put the cardboard box over the fan, mounted the hose on the box, and we were good to go. When I tested this at home, with just one child, it worked great. We had a fabulous time with it, shooting scarves into the air, shooting balls so they rolled across the floor for the dog to chase, shooting balls into a box for improvised “golf” game. Tons of fun for both of us.

But, then my husband tested it in a class full of kids. The first problem was that it kept falling apart. The fan tilts in its base, and if you tilt it too far, it pushes the cardboard box right off. (I may have forgotten to warn my husband about this issue… )  When kids put their hands in  and pulled them out quickly, that pulled the cardboard box off quickly. Just the weight of the hose could pull the box off. So, there was a lot of work involved in just keeping it together, and the kids weren’t that excited by the results even when it worked.

So, before the next time we’d use it in class, we did some tinkering. We used a ratchet strap to hold the hose onto the box and the box onto the fan. We turned it so the hose fed off the other side of the fan, over the handle, which helped to stabilize the box. This solved the falling apart problem. IMG_20150918_195451251

We had discovered that kids like it better when the scarves shoot vertically up into the air instead of shooting out horizontally, so we wove the hose through the legs of a stool to get that upward angle.IMG_20150918_195439255

Check out the video at the top of this post to see the scarf cannon in action.

We took it back to class, and this time, we had a hit on our hands! Lots of kids loved feeding through scarves, and balls.. We discovered that kids liked it even better when we set the stool up on top of the cubbies, so the scarves were shooting out from 4′ up in the air. The three biggest fans of this toy were a team of a 5 year old boy and a 4 year old boy, and a 2.3 year old girl. They discovered that if you sent through a balloon that was just the right size, it makes a really funny rumbly noise. The little girl was just as successful at using this invention as the older kids. She clearly learned from them. The boys had been having fun catching the scarves in a bin as they floated down toward the ground. When they walked away for awhile, she picked up the bin and tried to catch the scarves.

My next step is to try to re-create this thing we saw at a bounce house place… it was a batting cage, where a ball floated above a cone and the kids could hit it with a nerf bat. Right now, with a 4″ wide stream of air, my scarf cannon holds the ball right above the tube outlet. But I’m thinking if I got a traffic cone type shape that really focused the air, we might get enough lift to do this…


In our Inventors class, we are encouraging kids to tinker, and try things they’ve never done before. We tell them to build something, test it, re-build it, and so on. I am intentionally doing the same thing as I design activities for the class. Experimenting, failing, and trying again. This scarf cannon is still a work in progress, but it’s definitely a fun exploration!

You can also check out my experiments with building a wind tube, a marble run, and a water wall.


Since I wrote this post in 2015, we’ve updated our design. To find the most recent design and see more videos of our scarf cannon in action, check out this post on my other blog (Inventors of Tomorrow) about Fun with a Fan.

Building a Wind Tube

Wind Tube

For our Family Inventors’ Lab class (a STEM class for preschool and kindergarten age), we have built a fun tool, which encourages the kids to tinker – see my last post for how kids play with a wind tube. This post is about the tinkering process we used to build and refine our DIY wind tube.

We started with the directions from Exploratorium. We ordered from Amazon:

  • a big, powerful fan – we use the Honeywell HF-910 Turbo Force(My colleagues tried using a smaller fan, and smaller hoops to save money, and their version can just barely lift a scarf up and out of the tube. It’s just not nearly as fun as the bigger one. The Kodo wind tunnel uses this Vornado fan, and it’s larger cousin might be a good option)
  • 2 14″ embroidery/quilting hoops and
  • a acetate sheet  Ours is 40″ tall. You need about 48″ of it. Exploratorium’s directions called for .0075 ml thickness, we used .01. It’s a little pricier but it’s been very durable which is important to us because we transport it to several sites. (Other builders have used 1/32″ thick polycarbonate, but I haven’t found that in large sheets.)

We cut the acetate sheet, and assembled the tube with the hoops. Definitely a two person job. You can clamp the plastic between the inner and outer layer of the hoop, just like you would fabric. We then used clear packing tape to tape the seam. (We also taped over the metal clamps on the hoops, and the edges of the acetate sheet on one end, just so kids wouldn’t scrape themselves while playing.)

Then we needed spacers to lift the tube up off the fan. Exploratorium recommends wooden spacers that you cut a notch in. We built spacers with Duplos and set the tube on those. (You can see them in the videos in this post.) For our family, that worked fine, because it was easy to rebuild them if they got knocked off. For class, I wanted something I didn’t have to rebuild. I found some giant clothespins (like these), which worked great.

When using the tube with 2 – 4 year olds, I need to cover up the fan openings, just in case someone tried to put rocks or beans or coins or something into the fan. (Or fingers, of course. That wouldn’t be possible with this fan design, but it might be with other fans!) I bought 1.5 yards of black tulle with pretty sparkles (like this), and we wrapped it over the fan, tying it off below with a twisted pipe cleaner. The tulle does work great as safety proofing and looks fine, but it does diffuse the air flow from the fan a little, so some of the heavier things that would fly without the mesh on don’t fly well with the mesh on. I remove the mesh when I only have older kids who can be trusted if told not to try dropping small heavy things in…

At home, we just set the tube on top of the fan, but for class, I need to tie down the tube to the fan. Otherwise it’s easy for it to get knocked over and land on someone’s head. (Note: it doesn’t really hurt if it does, but it is mighty startling.)

Exploratorium recommended drilling holes in the spacers, disassembling the fan, and fastening the spacers on with zip ties. We decided it would be much easier to just thread pipe cleaners through the springs on the clothes pins, and loop those down through the fan and back up again (no dis-assembly required) and twist together to tighten. It was easy to do, worked great to tie them down, and is easy to undo later if desired. An advantage to the clothes pins is that it’s easy to clamp the tube onto the fan, then easy to un-clamp it for transport.

ClipMeshTieI’ve watched countless children age 1 – 10 play with this for hours. The under-one-year olds love just watching things fly up and out of the tube. The two-year-olds love shoving things into the tube and watching them fly. The three-year-olds start to make observations on which items flew best. The four-and-ups experiment with building things, tying things together, trying to put things in from the top, and so on. Some of the parents get caught into the experimenting too, folding paper helicopters and such to test what will fly. The kids play really well together – part of the point of this game is to put something in and LET GO, so there aren’t many issues with having to share something that someone was holding on tight to. They all play happily side by side. They don’t really need to take turns, as it works fine to have four or five things flying at the same time.

Here’s some of the items we have launched. (See some video in our Wind Tube post.) We look forward to more play and experimentation to see what other items we can find or build that will fly well in our wind tube.


Alternatives to our DIY wind tube

babbledabbledo describes building a simple “vortex” by just rolling a tube of poster board and setting it directly on the fan. Kids put a scarf or a balloon above the tube where it gets caught up in the rush of air. Super simple! I like that with our tube, the kids can put the item in at the bottom and see it travel up the tube, but this simple alternative may meet your needs just as well

Kodo Kids makes a wind tunnel that looks fabulous! And I know their materials are very high quality. I’d love to have it, but it costs $450 plus a $45 fan, versus the materials for this DIY tube are Around $140 before tax. [Fan ~$45; hoops $16; acetate sheet $50 ($35 for thinner material); clothespins $15; tulle fabric.]

Or you can buy the science museum version for $13,000.

There is also a DIY wind tube tutorial on Instructables. It requires that you own real tools, which I don’t. 🙂

For lots of ideas for STEM enrichment activities with kids, check out my blog www.InventorsOfTomorrow.com.


tinkerAt an in-service last week, after seeing this poster, I had a great conversation with one of my class’ teachers about the word “tinkering” and how great it is when parents allow their kids to tinker around, exploring, testing, fixing, breaking, and fixing again. So many skills are learned by this kind of hands-on exploration.

So, what is “tinkering”? Let’s ignore the definitions that say things like “unskillful or clumsy worker.” I like:

Children at play,  discovering new materials, and exploring new uses for familiar materials are Tinkers. People who were allowed to tinker a lot as children often become engineers, or scientists, because of that approach of “what happens if I try this? Oh cool! Now, what if I do that? Ooh, even better!”

People who were allowed to tinker a lot as children also become chefs, woodworkers, architects, computer designers, graphic artists, fashion designers, and builders. Learning early on the joys of building and creating and refining sets a lifelong passion for hands-on work in a variety of fields. (Check out this great post on The Importance of Learning to Make Things.)

How do you encourage your children to tinker? Give them lots of open-ended materials (cardboard boxes, toilet paper tubes, tape, string) and time to experiment. Talk to them about their creations, asking about the process and what they learned along the way. Ask them what they want to do next with their experiment.

I like this post from Kids Stuff World on Ten Powerful Life Lessons from TInkerlab. A couple of her lessons are:

  • The results are not as important as the process.
  • The more exposure you have to a material, the more you will learn what you can do with it.
  • Think of everything as an experiment.

Allowing your child to play, and tinker, and putter around, helps to ensure that as they get older, they meet this definition of Tinker: “somebody good at many tasks: somebody able to do many different kinds of work successfully.” (Bing dictionary)

If you’re in the Seattle area, and want to do some tinkering with your child, join our Family Inventors Lab!