STEM Learning: DIY Pumpkin Catapult for Kids (& Grown Ups Too)

This fall-themed STEM project supplied us with hours of fun! I mean who wouldn’t love learning about the Scientific Method by making a pumpkin catapult for kids?

I think most of us can agree that the advertising of holiday decor is appearing in stores earlier and earlier each year. As I was still in search of more beach toys this Summer, I couldn’t believe that certain department chains were already displaying Halloween costumes.

As a mom of three, everything feels like a rush. School drop offs, baby and me classes, extracurricular sports, grocery shopping, volunteering, squeezing in a shower, and so much more! So why do we have to rush the excitement of the upcoming seasons and holidays too?

Well, we decided that we were going to put our feet down. We would patiently wait until Fall arrived in Florida (which feels like never) and to help us bide our time, we would play with some mini-pumpkins until the cooler weather showed up!

My four boys (Yes, I recruited my handy hubby for this pumpkin project) and I made a miniature pumpkin catapult for kids to launch pumpkins across our driveway. Nothing gets my boys more excited than telling them they’ll get to smash stuff. This fall-themed STEM project was truly HOURS of fun!

My five-year-old is quite analytical, and you know I love sneaking educational concepts into our crafts, so prior to explaining how this contraption would be built, we reinforced the Scientific Method.

The Scientific Method

Step 1: Ask A Question.

How far did he think the miniature pumpkins would fly?

Step 2: Do Background Research.

What are our materials?
Is there anything else that can improve this or make the pumpkins go farther?

Step 3: Construct A Hypothesis.

He recognized that the smaller the pumpkin the farther it will go (HOORAY!)

Step 4: Test With An Experiment.

The entertaining part detailed below!

Step 5: Analyze Results / Draw A Conclusion.

Where we determined what worked for us and what we needed to improve.

Step 6: Communicate Results.

PUMPKIN CATAPULT FOR KIDS

Materials:

We used 1″ by 2″ wood for this project. Make sure it’s finished pine.

2 pieces of wood, each 5 5/8 inches long
3 pieces of wood, each 10 1/2 inches long (2 of these pieces need to have a square cut half the width of the wood on one end to form a “joint”.)
2 pieces of wood, each 18 inches long (Both of these pieces need to have a square cut out too for a joint for the uprights. The relief cut should start 4 1/8″ from the front of the catapult.)
1 piece of wood, 21 inches long (One edge should be cut on an angle.)
1 piece of wood, 7 inches long
A plastic cup or container to hold the mini pumpkin in
2 large eye hooks
A bunch of small drywall screws at least 1 1/4 inch
A 12-inch bungee cord
3/8″ x 8″ carriage bolt with one washer and a nut to fit
A piece of a pool noodle. (Not completely necessary, but it was a last minute addition made by my husband to increase the longevity of the cross arm.)
Gorilla tape, to decrease the resistance of the bungee cord (Also a last minute addition!)

Instructions:

Step 1: Cut all wood according to the measurements above. It may be easier to go into a store such as Home Depot or Lowes and ask them to cut it for you. Otherwise, a table saw will need to be used by an adult only. For anyone that knows me well, I’m not just a kid at heart, I’m a little clumsy too. So my husband was the adult in this situation

Step 2: Take your two 18 inch pieces and your two 5 5/8 inch pieces and screw them together on the outside of the structure. Screw one of your big eye hooks into the end; this will be the front of the catapult. Holes for the carriage bolt should be drilled 2 5/8″ from the front of the catapult.

Step 3: Screw the two upright 10 1/2″ pieces into place and then the 7-inch piece across the top of the two pieces you just attached. This should be attached to the rear of the uprights.

Step 4: Take your remaining 10 1/2″ inch piece of wood and cut angles on either end. This will be the support for the cross arm.

Step 5: Grab your 21-inch piece of wood and drill a 1/2″ hole 1″ from the end. This is for the 3/8″ carriage bolt to fit through.

Step 6: Insert the additional eye hook 5 1/2″ from the top (opposite end of the carriage bolt) of the 21-inch piece of wood.

Step 7: Line up the 21-inch piece of wood (swing arm) in the center of the box already created. Insert the carriage bolt through one side of the catapult, through the throwing arm and then through the other side of the catapult. Place a washer and a nut on the end of the carriage bolt and tighten just enough to get the head of the bolt to sink into the wood.

Step 8: Attach the bungee cord from the bottom eye hook to the top eye hook

Step 9: Attach the cup so there is a little bit of the swing arm out, so you can pull it down!

Modification: This is where we got a little creative! First, the bungee cord appeared to have too much pull and wasn’t shooting our pumpkins very far. We made a knot in the bungee cord to make it tighter and have more force. My husband also thought the swing arm rubbing against the wood was causing too much resistance, so he put Gorilla tape on the support arm. He then used a pool noodle to soften the impact of the throwing arm against the cross arm. The result? The bungee cord slid easily along the noodle causing less resistance and further shooting pumpkins!