Build a mini air cannon!
This is one of the 48 projects for our Instructables: Made In Your Mind (IMIYM) exhibition at the Children's Museum of Houston showing from May 26, 2012 - November 4, 2012. Produced in partnership with Instructables, IMIYM is an exhibit where families work together to build different fun, toy-like projects that help construct knowledge and skills related to science, technology, engineering, and mathematics while instilling a “do-it-yourself” attitude in kids so they feel empowered to explore, tinker, and try to make things themselves. To learn more, check out the article here.
For this project, we've taken an Instructable created by someone else and modified it for use in the Museum. This specific project is based on the Paper Cup Air Cannon project by MaddHatter, but there may be others on Instructables that are also similar. Often, we have to change the materials and/or process due to the large number of visitors (we see over 800,000 annually) and the need to ensure safety in a mostly non-facilitated environment. So, yes, many of these projects have room for improvement in both materials and methodology, which is PRECISELY what we want to encourage the kids to do. So please do share your ideas for improvement and modifications!
Step 1: What You Need
We are selective in our materials for cost, ease of use, and safety due to our high traffic (800,000 visitors annually). So, for our purposes, this design worked best. But you may have other ideas - please share!
1 - 16 oz Plastic Cup (soft plastic)
1 - CD
1 - 12” Balloon
Step 2: Video
Step 3: Step 1
Using the lowest line on the cup as a guide, cut off and remove the bottom of the cup. Keep the edge as straight as possible.
Step 4: Step 2
Using roughly 1” pieces of tape, tape the CD to the bottom of the cup. Make sure to completely seal the cup to the CD.
Step 5: Step 3
Cut off the straight part of the balloon. You only need the round part.
Step 6: Step 4
Stretch the balloon completely over the top of the cup, keeping it as tight as possible. Pre-stretching the balloon may help get it on more easily.
Step 7: Step 5
Optional - Use tape to secure the balloon to the cup. We find that some kids pull a little too hard and pull off their balloons.
Step 8: To Use
Aim the hole at a piece of paper (or other target), pull back on the balloon and let go!
Remember that the cup isn’t empty – it is full of air which is made of matter and therefore can exert a force. We see the force of air whenever wind blows things around. In the case of the Airzooka, when you pull the balloon back and release it, the balloon pushes some of the air inside the cup out through the hole in the other end. There is enough force in that traveling air to move other matter that’s pretty lightweight, like scraps of paper.