How to Make a Vacuum Cannon





Introduction: How to Make a Vacuum Cannon

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A vacuum cannon is an interesting physics demonstration that shows how much atmospheric pressure there is at the earths surface, though we do not feel it because our bodies have the same amount of pressure both inside and out. By removing air pressure from inside of a length of pipe the balance with atmospheric pressure is removed, and if the seal is broken on one end air pressure will rush in quickly enough to throw a projectile with a good deal of force.

To learn how I made the vacuum pump used to operate this cannon, take a look at this video:

The pump is very high quality, and pulls a vacuum much faster than most commercially available pumps, making it ideal for large tasks such as this cannon. Most other pumps would take many minutes to bring a chamber that size down below 25 in/Hg of vacuum.

I first learned of vacuum cannons thanks to this Instructable, and was interested enough to take the project on for myself:



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    Can a pump work for the cannon if it is singe stage?

    Is there something wrong with this page? I do not see an Instructable anywhere - just lots of sincere comments and a drawing of what looks like a sound suppressor.

    Ok thanks! I might just try it...sketch time.

    So a question... What if you evacuated the air from the cannon, but pumped that same air into another resovoir that is connected to the vacuum cannon by a ball valve from the back? This way you can use the atmospheric pressure as well as the principles from a regular pneumatic cannon? Would it be worth the trouble?

    It wouldn't be worth the trouble with a ball valve, but maybe with a fast acting sprinkler or piston valve.

    I came up with an upgrade for your vacuum cannon, I am working on a smaller version of yours, with my modification

    Is this more powerful than your coaxial piston cannon ?

    I have one all made up and ready to go, and wouldn't you know it, the 40mm pipe isn't actually 40mm, it's some obscure size, but is just referred to as 40mm as it's the closest whole number!! the ping pong balls won't fit!! grrrrr my science class was so disappointed!!

    This would be awesome in slo mo. Thanks for sharing