How to Make a Popsicle Stick Catapult (STEM Challenge for Kids)
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Learn physics, engineering, and creative design with this classic popsicle stick simple catapult project — perfect for classroom STEM, homeschool, or holiday fun! This old, but great one was due for a refresh! This STEM activity never goes out of style.
What Is a Catapult?
A catapult is a simple machine that uses stored energy to launch an object. When you press down on the lever arm of a catapult and let go, energy transfers from potential to kinetic — sending your projectile flying through the air.
Catapults have been used for thousands of years, from ancient Greece and Rome to medieval castles. They helped armies defend fortresses and launch stones or flaming projectiles over walls. Today, we use them for a much safer purpose: learning science in a hands-on, exciting way!
Today I am showing you a small desk top catapult. Also check out my jumbo one made with wooden dowels! Just as fun and easy!
Materials to Build a Popsicle Stick Catapult
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8–10 popsicle sticks (jumbo or regular size both work)
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1 plastic spoon or bottle cap
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Soft projectiles: mini marshmallows, pom poms, or paper balls
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Ruler or measuring tape (for testing distance)
Optional for extensions:
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Paper cup or target
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Angle template or protractor
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Holiday or theme decorations
How to Build a Popsicle Stick Catapult:
Step 1: Build the Base of the Catapult
Stack 6 popsicle sticks together and secure both ends tightly with rubber bands.
Step 2: Make the Lever Arm
Stack two sticks, band them together on one end only. Gently pull them apart at the un-banded end to form a “V.”
Step 3: Assemble the Catapult
Slide the stack of 6 sticks between the two sticks of the lever arm of the catapult — forming a cross or “T” shape. Secure it with one more rubber band at the intersection point.
Attach your plastic spoon to the top stick with a rubber band, hot glue or tape — the spoon becomes your launcher. You can also use a hot glue gun to attach a bottle cap to the end of the popsicle stick. Both methods work great!
Just for fun, let kids decorate their catapults with sharpie markers!
Step 4: Load and Launch Your Popsicle Stick Catapult!
Place a soft object in the spoon, push down gently, and release.
Adjust your angle, rubber band tightness, or lever position to experiment with distance.
STEM Concepts Learned from a Popsicle Stick Catapult
This simple project teaches key physics and engineering principles:
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Potential and kinetic energy
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Force and motion
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Angles and trajectory
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Elasticity and stored energy
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Iterative design and testing
You can even extend it with a STEM notebook challenge: predict, test, measure, and graph your results.
Popsicle Stick Catapult STEM Challenge Ideas:
Make it more than just play by turning it into a challenge:
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How far can your object fly? Measure distance with a ruler or tape.
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Try different launch materials – Which flies farther: a pom pom or a marshmallow?
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Change the angle – How does adjusting the base position affect launch distance?
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Add weight to the base to prevent tipping and compare results.
The Science Behind the Popsicle Stick Catapult
A catapult is a hands-on way to explore physics in motion and Newton’s Laws of Motion.
When you push down on the spoon, you store potential energy in the rubber bands and sticks.
When released, that energy transforms into kinetic energy, launching your projectile through the air.
Newton’s First Law – Inertia
An object at rest stays at rest until acted upon by an outside or external force.
The marshmallow or pom-pom stays still until the catapult arm releases, propelling it forward.
Newton’s Second Law – Force = Mass × Acceleration
The greater the force applied to an object, the greater its acceleration.
When you push harder on the spoon (adding more force) or tighten the rubber bands, the projectile’s acceleration increases — it flies faster and farther. Students can test this by changing the number of rubber bands on the popsicle stick catapult design or changing the projectile weight and recording the difference.
Newton’s Third Law – Action and Reaction
For every action, there is an equal and opposite reaction.
As you press down on the catapult arm, it pushes back with an opposite reaction when released. That opposing force sends your projectile flying upward and outward.
Other Physics Concepts at Work
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Gravity: After launch, gravity pulls the projectile back toward Earth, creating the arc-shaped path called a trajectory.
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Fulcrum: The stack of popsicle sticks acts as the fulcrum, or pivot point, where the lever arm moves. Adjusting its position changes the launch angle and distance.
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Acceleration: As energy transfers from the catapult to the projectile, the object’s speed increases rapidly — that’s acceleration in action!
Integrating Math and Measurement
Catapults make a perfect math and science crossover project.
Students can:
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Measure distance traveled after each launch.
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Calculate average range or speed (distance ÷ time).
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Record data and create graphs to compare different designs.
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Use angles and geometry to discuss trajectories and lever ratios.
By combining force, motion, gravity, and measurement, this simple catapult becomes a full STEM learning experience that covers physics, math, and engineering all in one fun project.
Holiday Catapult Variations
Give your popsicle stick catapult a festive twist for any season!
Fall, Halloween & THanksgiving
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Launch candy corn or mini pumpkins., cranberries or marshmallows for Thanksgiving
Christmas or Winter
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Launch mini jingle bells, pom-pom “snowballs,” or paper snowflakes.
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Create a “Santa’s Sleigh Launcher” challenge using red and green sticks.
Valentine’s Day
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Launch conversation hearts or paper arrows into “heart-shaped” targets.
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Add a lesson on force and motion using heart-shaped graph paper.
Spring / Easter
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Launch pastel pom-poms or tiny eggs.
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STEM tie-in: measure and compare projectile weights.
Summer or 4th of July
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Use red, white, and blue materials.
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Launch tissue-paper “fireworks” safely indoors.
Each holiday version keeps engagement high while reinforcing key physics principles.
Common Questions About Popsicle Stick Catapults
What’s the best projectile to use?
Soft, lightweight items like pom-poms, marshmallows, or paper balls are safest and easiest to launch indoors.
How can I make my catapult launch farther?
Use more rubber bands for extra tension, or increase the length of your lever arm (spoon handle).
Can I make a trebuchet with craft sticks?
Yes! A small working trebuchet can be made using popsicle sticks, a string sling, and a counterweight (like a washer or nut). It’s a great advanced STEM project — I’ll be sharing a tutorial for that soon.
Is this safe for classrooms?
Yes — as long as you use soft projectiles and supervise testing. Avoid hard or sharp objects.
More Simple Machines Activities:
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Build a Large Catapult with Dowels & Rubber Bands
- Three Little Pigs STEM Project for Kids
This easy catapult craft is a great entry point into engineering fun for kids of all ages. Try it out today and watch those mini marshmallows fly—along with your kids’ curiosity and creativity!
