Here’s a great summer project for kids – build a catapult out of pre-cut dowel rods and rubber bands!

Build a catapult to shoot splash bombs or ping pong balls

Over the years, we’ve done a lot of exploring with catapult making!  We’ve built them out of Tinker Toys and tissue boxes, and even just used forks as catapults!  Aidan and I have been on a quest the past couple of years to design a catapult that will launch water balloons.  We were hoping that this one would do the trick, but alas, water balloons are really hard to launch because of their weight and wiggly shape.  However, this catapult shoots ping pong balls and water bombs really well, and building it does not require special tools or a trip to the hardware store!

How to build a catapult out of dowel rods and rubber bands

The design of our catapult was inspired by this post that I found on Pinterest.  I found the photo of the pencil catapult on Pinterest, but the instructions in the post don’t fit with the picture.  I figured that dowel rods might make a bigger and stronger catapult, so we decided to do that instead of pencils.

To make this catapult, you will need:

  • 12 dowel rods – I used pre-cut 12″ and 3/8″ diameter dowel rods that I found at Hobby Lobby.
  • Rubber bands
  • A juice bottle lid or similar object to use as an ammunition basket
  • Low temp glue gun
  • Something to shoot – ping pong balls or water splash bombs.  We also had good success with homemade sponge water bombs

Step 1:  Use rubber bands to make a “T” shape with two dowel rods.  Then add three more rods to make the square base of the catapult, like this.  (If you make the base first, you’ll end up having to take it apart to add the vertical piece for the shooting arm.)

How to make a catapult with dowel rods and rubber bandsStep 2:  Add 1 vertical rod to each corner.  Add a horizontal rod at the top on the side where the shooting arm is.

How to build a catapult out of dowel rods and rubber bands

Step 3:  Add a horizontal rod to the other side, where you should currently have two loose vertical rods.  Put this horizontal rod a couple of inches down from the top.  Then, connect all of the vertical rods at the top, so that your catapult looks like this.

How to build a catapult out of dowel rods and rubber bands

Step 4:  In order to make the shooting arm long enough, we added a second dowel rod.  If you’re not buying them pre-cut, you could just make that piece longer.  However, I figured it was easier and cheaper to buy the pre-cut ones.

We used a long blue rubber band to give tension to the shooting arm.

How to build a catapult out of dowel rods and rubber bands

Step 5:  Glue on your ammunition basket, and you’re ready to fire!

How to build a catapult out of dowel rods and rubber bands.My husband and my almost 10 year old assembled the catapult together.  Aidan could probably assemble it himself now that he knows how to do it.  My husband thought that it was a good project for learning how to wrap the rubber bands so that everything stayed together, since that’s a good life skill to have.   Aidan enjoyed tinkering with the catapult to get it to shoot as far as possible.  He really enjoys engineering type activities like that.

How to build a catapult out of pre-cut dowel rods and rubber bandsExtend the catapult fun with some variables to test!  

  • Add additional or tighter rubber bands.  Does additional torque affect the catapult’s power?
  • Try changing the angle of the rubber bands. 
  • What objects shoot the farthest?  Try ping pong balls, marshmallows, pom pom balls, etc.
  • Which travels farther – a dry splash bomb or a wet splash bomb?

25 Comments

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  1. Anna - the Measured Mom Jun 7, 2013

    Wow, that looks like a boy's dream! I am not quite ready for my 4 year old to try this, but wow would he love it!!

    Reply
    1. Julian Mar 8, 2016

      That is so cool I'm about to use that as a project

      Reply
      1. Boogie Mar 22, 2018

        glad to know

        Reply
      2. JDaniel4's Mom Jun 7, 2013

        My son and the boy next door would both love one of these. I am pinning this post.

        Reply
        1. Chloe Jun 11, 2013

          I just made this with my 3 years old son. He helped me just by choosing the rubber bands, and enjoyed looking me making a new toy. He's playing with it for 1 hour and is anxious to show it to his friends!
          Thank you for the idea and explanations!

          Reply
          1. Amelia Sep 5, 2016

            Thank you I look forward for doing for my catapult project at school

            Reply
          2. Allison Jun 14, 2013

            This is so stinking cool Sarah! I'm featuring this on The Sunday Showcase this weekend!

            Reply
            1. Kathy Jul 4, 2013

              Very fun activity! Thanks for sharing. My daughter loved making hers and playing with it! Made for a fabulous July 4th family activity!

              Reply
              1. Stephanie Aug 10, 2013

                My husband says "This woman needs to be introduced to zip ties". HAhahahaha...

                Reply
                1. kiki Oct 15, 2013

                  cool

                  Reply
                  1. Sarah Oct 27, 2013

                    Im going to use this for a school project, wish me luck !

                    Reply
                    1. Cindy Gooch Jan 25, 2014

                      This looks awesome! I'm going to make this with my boys...I had an idea though...what if you used a wooden spoon for the ammo basket instead of a dowel with a lid glued on???

                      Reply
                      1. Sarah Jan 25, 2014

                        Now that is a good idea!! Thanks for the suggestion!

                        Reply
                      2. DIY Toys Jun 10, 2014

                        Awesome, gona make this for my kids!!

                        Reply
                        1. Vicki Jul 5, 2014

                          Zip ties! Some of the rubber bands just not working. Also anchoring it to peg board!

                          Reply
                          1. Sarah Jul 6, 2014

                            Those are great ideas! We love zip ties!

                            Reply
                          2. erinn Sep 29, 2014

                            thats a great idea

                            Reply
                            1. Courtney Oct 29, 2014

                              I think this would be a good for my project that I have to do!

                              Reply
                              1. Emily Connolly Nov 11, 2014

                                THIS SAVED MY PHYSICS GRADE! Thanks so much, easy to follow! Plus me and my partner already had all the supplies needed so yay! We also hot glued the joints after using elastics to make them stronger.

                                Reply
                                1. brittani wood Dec 5, 2014

                                  i think the catapult project is a very cool thing to do as a project

                                  Reply
                                  1. Mary Mar 8, 2015

                                    I'm going to make this with my girls. They would love this.

                                    Reply
                                    1. Dudelup Feb 8, 2016

                                      Awesome

                                      Reply
                                      1. Darlene Lenart Mar 13, 2016

                                        I will make some for on my sons eagle scout party they made one In scouts and had a blast with it thought it would be cool as a table dec.Thanks

                                        Reply
                                        1. connor Aug 17, 2016

                                          this is actually really cool, I'm going to use it for my school project, thanks.
                                          -connor

                                          Reply
                                          1. Jay Jay Justice Jan 31, 2017

                                            thank you for the idea i will be using this at school for my engineering project.

                                            Thank you!

                                            Reply
                                            1. Kishi Jan 18, 2018

                                              Thank you for this project, I won a catapult competition at school thanks to this

                                              Reply
                                              1. Ron May 10, 2018

                                                The rubber bands are good to build with but no stability. I recommend zip ties to secure the structure. A base is my next move.

                                                Reply
                                                1. Isabella Lee May 24, 2018

                                                  Thank you so much for this idea! I'm currently working on a catapult project in my physics class so I'll be definitely using this idea!

                                                  Reply
                                                  1. Jenni Giesler Jun 15, 2018

                                                    We had so much fun with this! Love your blog!

                                                    Reply
                                                    1. Morgan Mar 31, 2019

                                                      Great catapult! using it for school project about the ancient Greeks. I thought it would take me hours but took less than 25 min. I am also adding wooden slats and wheels to the bottom to be more like a ancient catapult.

                                                      Reply
                                                      1. Lorraine May 1, 2019

                                                        Making this for a school project as well!!!!! Hope I win the contest!!!!!!!!! yay

                                                        Reply

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