Balloon Hovercraft

by CMHouston

30K5710

Intro: Balloon Hovercraft

Design a toy hovercraft!

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.

While we created this project, we found a similar project with the CD Hovercraft by Vitaman X, but there may be others on Instructables that are also similar. Often, the materials and process for building our projects are designed for use with a 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 - Short Wood Spool - we use a 3/4" diameter x 1" high spool. We purchase ours (in bulk) from Craft America
1 - CD
1 - 12” Balloon
1 - Straw
Masking Tape

STEP 2: The Video

We offer optional video segments of each step in the actual exhibit. Here is a compilation of all the steps.

STEP 3: Step 1

Center the spool over the hole in the center of the CD. Make sure the holes line up and, using several 1” pieces of tape, tape the spool to the CD. Make sure to completely seal the bottom edge of the spool to the CD.

STEP 4: Step 2

Stretch the balloon over the top of the spool. If you want, you can tape the balloon to the spool, but it isn't necessary.

STEP 5: Step 3

Using the straw, blow through the hole in the bottom of the CD to inflate the balloon. Pinch the balloon, so the air cannot escape.

STEP 6: To Use

While holding the balloon, place the CD flat onto the table. Let go of the balloon and give the hovercraft a gentle push.

air flows out of the balloon, through the spool, and under the CD. Because the CD has a very flat surface and is evenly weighted, it lifts the entire hovercraft off the table. The air cushion between the CD and the table reduces the friction (a force that slows moving objects) and allows the Balloon Hovercraft to glide along the table. This is a similar principle to what allows air hockey pucks to float (although their air cushion comes up from the table).

10 Comments

spectrUMDiscoveryArea 4 years ago

We've used this same activity extensively in our science museum as well as classrooms, mostly with 4th-6th graders. In adapting it for our use in the classroom, we've developed a separate Instructable (found here: https://www.instructables.com/id/CD-and-Balloon-Hovercrafts-Engineering-Challenge/) as well as printed curriculum that indicates NGSS science standards addressed. See the attached .pdf for more information on that. Hovercrafts is covered on pages 10-11, and standards 32-34.

Instead of the thread spool, we typically use old film canisters donated by the local film developing shop (if you don't have a store like that, consider places like Walgreens, CVS or WalMart/Target that develop film). Poke the holes with a tack - we purchase very large novelty size tacks that help the kids do this safely. A benefit of this is being able to change the flow of the balloon based on the number of holes poked.

Additionally, we also include an engineering component - try to design something that holds the balloon steady while the hovercraft is in "flight". Popsicle sticks, pipe cleaners, toilet paper tubes, paper and hot glue/tape are all typical supplies we put out for this component. We find it changes a 20min activity into a 45-60 min activity by adding this piece, and you end up with a VERY diverse set of hovercrafts. Sometimes kids will even combine their two hovercrafts into one!

Lastly, for use with large classrooms we've found it best to get a balloon pump so that the kids don't have to struggle with blowing the balloon up multiple times. See the Instructable page linked above for a 3D printed adapter for balloon pumps to make this process easier. A chunk of vinyl tubing that matches the inside diameter of the CD hole can work well also.

Some helpful questions to include during facilitation during class time:
  • How does the number of holes change how the hovercraft flies?
  • What happens if you don't seal the bottom of the film canister?
  • How can you make your hovercraft float longer? Glide faster?
  • What happens when we add the additional weight of the support structure?
  • What would happen if we had a bigger disc? Would the balloon we use be able to lift it?
  • How are hovercrafts used in real life?
  • Where else is the idea of creating a layer of air between things to reduce friction used (i.e. air hockey tables, lifting large loads, manufacturing)?

Crystal33 7 years ago

this is great! My 6 year old has a recycle project due next week & this is perfect!

Do u know if this would work with a sports bottle cap instead of straw & spool? I tried it but think I am not doing it right :) thanx!

Wish we could go to your museum, sounds super awesome!! But... We live all the way in PA :(

kostfeld 7 years ago

Yes, I think it will work with the bottle cap, but with some modifications. First, I suggest you flip the cap upside down so the smooth side is against the ground/table. I would also suggest taking a soda bottle cap and use a nail to punch a hole in the top. Then, punch a matching hole on the sports bottle cap. Finally, hot glue (or superglue) them together. This way, the balloon nozzle could go over the soda bottle cap (you way want to tape the balloon in place depending on the size of the nozzle), but the air blows out under the sports bottle cap.

Or, maybe I'm misunderstanding and you are asking if you can use a sports bottle cap attached to a CD? In that case, you'll still need to punch a hole in the cap and glue/tape it to the CD (I always recommend hot gluing over taping, but at the museum we had to use tape). But, make sure you can stretch the balloon nozzle over the cap. The great thing about the spool was it had a built-in hole and a nice fit for the balloon.

I didn't build a prototype, but in my head in seems like either will work. Good luck! I'd love to see the final result!

HaunTech Haunts 10 years ago

This is a great instruct able to do with my gf she loves it thanks

wilgubeast 11 years ago

Awesome. If you are in Houston, GO TO THIS MUSEUM. (Preferably while this exhibit is running, but stop by whenever you can.)

CMHouston 11 years ago

Woohoo! Love the free advertising! Thanks!
The exhibit opens this Saturday (5/26) and runs until Nov 4th. Hope to see everyone!

craftknowitall 11 years ago

Wow will need to add this to my kid science board. Thanks.

CMHouston 11 years ago

Thank you! Keep watching as I get the other projects up.