We’ve wanted to try a hovercraft experiment since we saw a really cool leaf blower hovercraft (like this one) at a science show last year. As we don’t have access to a leaf blower, we used balloon-power!
There are many variations on this experiment. We tried quite a few. I’ll start with the one that worked best and then show you some of the others. (Maybe you’ll have better luck with them.)
What you need
* old CD
* hot glue gun
* sports cap from a water bottle (the kind that you pull up to drink and push down to close)
* push pin (drawing pin)
* large balloon
* a big smooth surface
What you do
1. Use the push pin to make two holes in the cap near the centre.
2. Spread a thin layer of hot glue around the base of the bottle cap and attach it to the CD, over the hole. Give the cap a slight twist as you stick it to ensure an airtight seal.
3. Make sure the cap is down (closed).
4. Blow up your balloon and pinch its neck while you attach it to the top part of the cap. (Easiest with two people.)
5. Place your hovercraft on a smooth flat surface. Give it a push and see what happens {not much}.
6. Now, without removing the balloon, pull up and open the cap. Quickly give the hovercraft a push and watch it continue moving. Push your hovercraft back and forth across a flat surface to keep it moving until the balloon is fully deflated.
Notes: (1) I’ve since seen the experiment set up this way in Science Experiments, but without the pushpin holes
(2) I’ve also seen a version that uses sticky tack (Blue Tack) instead of hot glue
The scientific explanation
When you push the hovercraft when the cap is closed (stage 5 above) , friction between the CD and the surface soon stops it moving.
But when you open the cap, air escaping from the balloon cushions the hovercraft. The hovercraft continues moving much farther.
Variations that didn’t work for us {but it’s good to experiment}
1. First we tried making Science Bob’s hovercraft. This involved taping over the CD hole and making six push pin holes in it. No holes were in the lid.
Verdict: A complete dud! I’m not sure what we did wrong, but this hovercraft didn’t do much for us.
2. The version that eventually worked for us was from Steve Spangler Science. But Steve Spangler suggests making a cardboard collar for the hovercraft.
Verdict: We made a collar and the hovercraft worked fine, but it was very fiddly trying to get everything attached and the cap open. We eventually removed the collar in frustration, and found that the hovercraft worked just as well without it.
3. We tried making a hovercraft just using a paper plate and balloon.
Verdict: Another dud! Perhaps we didn’t make our centre hole big enough?
Hovercraft History
The first modern hovercraft was designed in the 1950’s by Englishman Sir Christopher Cockerel. It crossed the English Channel between Dover, England and Calais, France in two hours.
Until the year 2000, passengers could travel from England to France by hovercraft in just 35 minutes. Passenger hovercrafts still operate between Southsea, England, and the Isle of Wight.
Hovercrafts are a type of seaplane, and they require large amounts of expensive aviation fuel to keep their giant air-cushions inflated. This is one of the reasons large hovercrafts are less commonly used nowadays.
Military Hovercrafts
Because hovercrafts are able to cross any flat terrain, including water, marshland, tarmac and sand, they are still commonly used for military purposes.
The biggest hovercraft in the world – the Zubr – recently made the news when it landed on a Russian beach filled with hundreds of sunbathers. A Russian defence spokesman reportedly commented, “What people were doing at the beach on the territory of a military base is unclear.” Okay, then!
Sources
History of the Hovercraft – Squidoo
Giant Hovercraft Retire after 30 Years of Channel Crossings
Coming Up
Next time – How to make a hydraulic lift
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I’m appreciatively linking up here:
Highhill Education – Entertaining and Educational – Sept 19
Homegrown Learners – Collage Friday
Hammock Tracks – Look What We Did!
Weird Unsocialized Homeschoolers – Weekly Wrap Up
Teach Beside Me – Share It Saturday
Adventures In Mommydom – Science Sunday
Learn Play Imagine – The Sunday Showcase
Hip Homeschool Moms – Hip Homeschool Hop 9/24/13
All For the Boys – Let’s Hear it for the Boy
Lucinda,
I love the big smiles in the photos. Obviously everyone enjoyed this experiment. I remember going on a hovercraft many years ago, somewhere on the south coast of England, maybe near Portsmouth. We could have been going to the Isle of Wight. Would that be possible from Portsmouth? It was a long time ago so I have forgotten the details!
Hello Sue,
Yes I think Southsea is near Portsmouth, and in fact one website said Portsmouth instead of Southsea, so that may well be where you went from. There’s a hovercraft museum there, apparently – I’m going to ask the children if they fancy a trip down there, I think! Have a lovely weekend! Lucinda
We did these a few years ago and the kids loved it!
It’s a fun one, isn’t it Savannah?
I always thought hovercrafts are really cool. Never been on one, although I was very excited when I spotted one on the way to the Isle of Wight. We tried to a similiar activity a few years ago but it didn’t work. Well done with persisting with it and trying different ways to make it work!
Thank you. I went to France on one once. Took it completely for granted, and only really felt excited about it when I did the research for this post! 😀
This is great! We may have to try this ourselves, so thanks for the instructions!
Thank you, Jamie!
I’ve never thought about a hovercraft experiment before, thanks for the idea!
Always like to share the inspiration, Amy! Thank you for stopping to say hi!
I’m impressed with your perseverance. My son could have hung with you, but I think I would have given up. It’s so cool you found a version that worked. Now it’s time to read a Wright Brother biography – they persevered many years just like you guys:)
Good idea, Julie! 🙂
So Cool! What an awesome day of science.
blessings, dawn
Thanks very much, Dawn! Blessings, Lucinda
This looks exciting. My children love “fun science” so we must give this a go.
Good luck with it, Sarah!
I came over from Highhill Homeschool – this looks like a lot of fun. I am pinning it so I can remember to try it with my son.
It was fun, Dana. I’m pinning your tie dye, too 🙂
Wow, such a cool experiment! I just remembered I had a project I wanted to do this week with old CDs!!! I see a weekend project now!
Thank you, Jen! Enjoy your CD project!
This is great! I especially like the fact you compared what worked and what didn’t. And I love all the smiles!
Thanks Claire! We had a lot of “didn’t work” to work with! 😀
Very cool! I just finished reading some books about hover cars (fiction) with my son and I’m sure he would love to do this to get an idea how hover cars work. Thank you for sharing!
I found your post on Science Sunday.
Ooh – hover cars sound fun!
You know I couldn’t quite decide which of my science boards to put this on, so I put it on my general science board.
This looks like so much fun! Thanks for linking up to Science Sunday!
I’m like that with my science boards too. And tags on here. Thanks for pinning and hosting!
science is the best thing ever i love experiments
I agree!
What is the point of putting the holes in the cap? Don’t these holes cause air to leak out prematurely? Would it work without the holes?
Adam, To be honest I just followed the instructions Steve Spangler gives. My guess is that the holes allow the air to escape from the balloon more evenly. Steve Spangler suggests increasing their size and number if the hovercraft doesn’t move freely. The aim is to create a smooth cushion of air, reducing the friction between the CD and the surface.
You could try it without the holes – there seem to be lots of variations. If you do, I’d love to hear how you get on!
This helped LOTS!
I’m glad. Thank you for commenting!