Fantastic Fall STEM Challenge: Make Use-What-You-Can Catapult

Inside: This acorn catapult is easy to make with things you already have handy – sticks, spoons, and hair ties. For an extra challenge, shoot at a target or download our Acorn Catapult Challenge printable.

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STEM challenges are one of my favorite things to do with my kids, maybe because they make me feel like a kid again. Who doesn’t like shooting acorns out of a catapult across the yard?!

Or perhaps it’s because our STEM projects are often something my kids end up playing with for days on end (proving once and for all that those simple homemade toys can be way more fun than fancy toys from the store).

If you have a pile of acorns, the first thing that usually comes to mind is shooting them out of a catapult, right? Maybe it’s just me.

Building a classical catapult usually requires popsicle sticks, rubber bands, and pretty plastic spoons.

Unfortunately, I recently organized my STEM supplies, which means

1. I now can’t find anything
2. I don’t want to touch a thing, so I don’t mess it up again,
3. I wonder why I ever touched my messy pile in the first place (my life was so much easier before I organized my mess) LOL

But you know how it goes in life: challenges help you come up with solutions that end up being superior to the original plan!

My kids ended up discovering that you don’t need any special supplies to build a STEM toy. We went for a stroll around our yard to find some sturdy sticks, and then took a regular spoon from my cup (I was drinking tea at the time) and added a hair tie that I had pulled off my ponytail, and voila! The Use-What-You-Can Catapult was born.

The. Best. Toy. Ever.

See for yourself. Click on the video below.

If you don’t have any special supplies laying around, follow along for our easy instructions.

Your kids will:

• Practice observation, communication, and experimentation (Science)
• Learn the basics of construction and utilization of simple tools (Technology)
• Discover the pleasures of engineering while building the catapult (Engineering)
• Explore shapes, lines, angles, and other mathematical relationships (Math)

Yep, the whole STEM package with one fun activity.

You’re welcome.

What you Need

• Sticks
• Spoon
• Something with elasticity to it (I.e., hair ties, ponytail holders, rubber bands, etc.)
• Acorns (such great ammo!)

What to Do

• Go for a stick collecting expedition and bring back a load of sticks (make sure to include Y-shaped ones). Ask kids to think of their goal “building a catapult” and then play around with sticks, arranging them in every imaginable way to see what ideas come to mind. That’s how we came up with today’s idea: by arranging sticks in different ways and envisioning in our minds how it would work in the real world.

HINT: Remind them that a catapult is a device for launching objects (acorns) through the air. How can we use a stick to become a device that helps acorns accelerate through the air in a straight line defying gravity for a little bit? Could Newton’s laws of physics help in any way? Do they know that catapults are often called slingshots? What are slingshots? Read my previous catapult post on the science of how it works.

• I was originally planning to guide my kids toward the construction of a catapult similar to what we did to build the Star Wars Ewok Catapult.

We used four sticks as a base, two on each side to create a cross, and two in the middle to do the actual work.

While we were playing with sticks, however, we realized that we could easily build a catapult with three sticks and the spoon I was using for stirring my tea at the time. I only had to add the elastic hair tie from my ponytail to help convert potential energy into kinetic energy.

Good construction, right? But a better idea came …  while we were looking at a Y-shaped stick. Aha! We thought. A sling!

Grab a V-shaped stick, a hair tie, and a spoon. Line the spoon on top of the stick, so that the top is between the V of the branches. Secure with a tie. Done!

The higher the spoon, the farther the acorn goes, but it might be challenging for little kids to operate. We keep the spoon low on a pic above, so my four-year-old can use it.

Now all you have to do is to add an acorn to the spoon, pull back, and release! Acorns do make excellent projectiles, right?

How far can your acorns go?

Ours went pretty far!!!

My preschooler enjoyed using the catapult placed on the ground, while I held one side for stability. It takes a bit of an effort to pull the spoon back far enough to create enough potential energy to make an acorn fly far. My older kids all preferred to hold our little device in the air like a slingshot and shoot in all directions.

Either way, it was a lot of fun!

If you are like us and can’t resist the urge to turn it into a challenge, here is a printable for you. In case you don’t know, there is nothing that promotes sibling love better than the Parents Vs Us challenges.  Sneaky, right?

Print it out below. 

But in case you are using it with grandparents, or a group of kids opposite another group of kids, I’m also including a blank copy for you to fill out.