Instructables
In five minutes, you can build an air-powered bazooka. The bazooka launches plastic capsules about 100 feet. And with some tweaking, you might stretch that distance quite a bit.

Although everything you need to know is in the pictures, the video tells the whole story just as well…

If the video is not playing, have a look at it here...

All you need to know to build this low-pressure kid's gun is described in the texts, as well as in the comments with the pictures. Have fun building and shooting! But please be careful, don't point your self made bazooka to living creatures.
 
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Step 1: Stuff you need

Stuff you need:
  • A vacuum cleaner. Any model will do.
  • Straight piece of PVC tube, at least 1 meter long. Longer is better (see the text on tweaking)!
  • Inner diameter 35 mm (1.4").
  • A PVC 3-way junction with an angle of 45°, that fits the straight PVC tube.
  • Duct tape.
  • A projectile: I used the plastic capsule that is inside "surprise-eggs" (see picture). Old school film containers work as well. Whatever you use, make sure that the projectile's diameter is just a little smaller than the PVC tubes'.
  • A small piece of cardboard (business cards are perfect).

Step 2: Make it

  • Attach the 3-way junction to the straight tube, using duct tape (you can glue the parts with PVC glue, of course, but there's no good reason to do so).
  • Wrap duct tape around the tip of the vacuum cleaners' hose, so that it fits snugly into the slanting tube. This fit should be as air-tight as possible.
  • Push the vacuum-cleaners' hose into the slanting tube of the pvc junction part.
  • Test whether the projectile can run smoothly through the assembles PVC tubes, when the vacuum-cleaner is attached.
  • That's it :D

This is really awesome guys, way to go on winning the challenge!
ynze (author)  NightHawkInLight3 years ago
Thanks!!! We're having a ball here :D
Here's how I did mine. I used 1-1/4" sch 40 PVC pipe for the launch tube, and 3/4" sch 40 PVC pipe with caps for the projectiles. They fit perfect with no modifications.

Home Depot didn't carry a 45 degree 1-1/4" Y or T joint, so I went with a regular 90 degree Tee. I used a 1" elbow to get some angle on the inlet. The 1" elbow fit tight enough inside the 1-1/4" T. I didn't use cement on any of the joints.

I tried 2 different lengths for the projectiles (about 6" and about 3"), with and without sand for weight. They seemed to fly farther without the sand. I also tried a shorter launch tube - 2 ft instead of 3 feet. The longer tube launched them farther as well. I didn't measure, but it was probably in the 50-60' range, depending on the angle.

The ID of the 1" elbow was a good fit for my vacuum cleaner's hose, so I didn't need any tape there.

Thanks for posting a great instructable! Hope you win the contest!

Vince
SANY0081 (Large).JPGSANY0083 (Large).JPG
A good example of matching the energy level of your vacuum system to the weight of a projectile. If you wanted to find the ideal length of tubing to use for a projectile, you could try firing the tubes into a cardboard box that has a pillow inside. Then measure how far the box slides on each shot. I would add some packaging tape to the bottom of the box, because the amount of force to get the box to start moving needs to be both low and consistent over many shots.
ynze (author)  bloomautomatic3 years ago
Thanks! And thanks for your pictures, too! The pvc projectiles look impressive. Adding the sand makes them just too heavy for your vacuum cleaners' power, I guess. The Kinder egg capsules weigh almost nothing, compared to your projectiles...
Do you need a vacuum that can blow ?
IVT1 year ago
Genious!
SGT. Desert2 years ago
aoswme i use supprize eggez and sand in it small and dirty ( my extra add a nail to the head of the egg )
Just make it a condition, before the kids play with the vacuum they have to use it first!
Perfect plan - clean the house, then you can use the vacuum to pelt the neighborhood!
marcintosh3 years ago
my large Ridgid brand shop vac, smaller hose and perhaps a few hard boiled eggs OH YEAH!
This'll be great at the annual family reunion. The kids and I will have a blast.
Hard boiled? Seems that it might hurt if things go badly, like idiots in front of the cannon....

The impact will be far more exciting with raw eggs splattering something 100 feet away!
neologik2 years ago
excelent!!! very good .. does this work with water baloons?

hehe

greets
thejevans2 years ago
All I see is an unfinished Airsoft RPG Launcher. fill the egg with BBs and an m120. Stick the fuse out of the bottom of the egg. Light the fuse, and shoot the egg. Lots of experimenting with timing would be necessary, but I think the end result would be worth it.
The Vacuum Bazooka is indeed in my Vacuum Bazooka book- and the rapid fire multiple projectile version is in my soon to be published book-Ultimate Saturday Science. I have 2 other books - Ink Sandwiches and Exploding Disk Cannons. You can see other projects on you tube (try nddownie) and on the Eli Whitney Museum website.

Have fun! Neil A Downie
Nachimir3 years ago
So lovely, and simple. Thanks :)
PS1183 years ago
For whatever reason I can't reply to bloomautomatic's post, but...

I couldn't find the PVC Y fitting at Lowes either. BUT... they do have them in the black sewer pipe section!
could i make it with a 90 degree elbow piece?
ynze (author)  dylankunaikennedy3 years ago
Yes. The chance that your projectile will get stuck is slightly bigger, but if you choose projectiles that are a bit longer than the plastic eggs I use, it won't be a problem.
instead of a 3 way connector?
ynze (author)  dylankunaikennedy3 years ago
Have a look at Bloomautomatic's comment (with pics). Is that what you mean with a 90 degree elbow piece? That version works!
avatar_i3 years ago
That is completely incredible!

After reading this instructable, I made mine with leftover parts lying around the shop using: a BIG shop vac, a 4.5 foot long metal pipe, and Gorilla Tape.
I sent a 35mm film canister filled with flower about 140 feet on the first try.
The only [other?] thing I did differently was to put a small hinge on a very thin strip of brass to act as the "stopper" [?] on the muzzle end, so I did not need to have a pile of business cards, or scamper to find the last one that wsa shot off the end.
Man, whas that ever fun, but my Dogs hate me now!!!
I wonder what would happen if I used an old belt driven compressor with a 4" piston, weighing about 85 pounds...

MWWWAAAAHHAHAHAHAHA!

The Trouble I could get into is ENDLESS!!
One.3 years ago
AWESOME! AWESOME! WAEOSEM! wish I thought of this!
evilmadcow3 years ago
suuuweeeett.
From Bill Gurstelle's book "Backyard Ballistics" ! An excellent instructable. We did it with water filled 35mm film cans- a really nice fit in standard pipe.
good idea. I live in the U.S. so getting an egg like that would cost a fortune.
ynze (author)  steveastrouk3 years ago
I wasn't aware it was in Backyard Ballistics. I first made it in 2006, and was told about it by a colleague science teacher...
Sorry, my bad, wrong book, its http://www.amazon.co.uk/Bazookas-Electric-Rainbow-Saturday-Projects/dp/0691009864
ynze (author)  steveastrouk3 years ago
What about this book:
"Vacuum Bazookas, Electric Rainbow Jelly and 27 other saturday science projects", by Neil A. Downie?

I think the vacuum cleaner bazooka just MIGHT be in there, too :D

ISBN 0-691 00986-4

Y.
That's the one in my link above your comment. http://www.amazon.co.uk/Bazookas-Electric-Rainbow-Saturday-Projects/dp/0691009864
 Bold is ISBN number

Steve
ynze (author)  steveastrouk3 years ago
Ah, I see :) The book was on my shelf for AGES. I bought it because the physics behind the projects are very well written out...
Hey there, I made a version of this with the kids on the weekend!! Brilliant!! Thanks for posting, it was so simple that they were able to assist with most of the construction.... absolutely ingenious!! Cheeeers!
ynze (author)  danielthomas723 years ago
Thanks :D
astrong03 years ago
what if you used a shop vac....
Range over 200 feet.
deadly
http://www.instructables.com/id/Automatic-Vacuum-Powered-Paint-Marker/

So I think I can say that this is very cool! And if you add a hinge to the business card with a travel stop so it can't open any further than 90 degrees, the suction will pull it closed and you could have a rapid second shot.

I used 3/4 inch PVC pipe, with paintballs.
ynze (author)  Shadetree Engineer3 years ago
Yup, I like your automatic weapon a lot! I had a look at it before I entered my bazooka. The physics of our projects are the same, the construction is different.

Adding a travel stop to the card is a smart idea. If that works, a cartridge containing several projectiles can be added, too...
'weapon' is an overstatement, it had trouble breaking all the paint. But using a continuous flow of air to move projectiles looks promising. My goal is merely to get 300 FPS, all other serious research in a device like this was to get over 1000. 300 is the legal limit for playing fields.

A travel stop mod would be easy to add to your existing bazooka. A hinge can be a piece of duct tape. The stop itself, a piece of coat hanger wire bent into a U and taped to the side of the muzzle, right over the tape hinge.

But that would be the easy way. I would like to see a 6-inch section of 2 x 2 square tube hot-glued across the muzzle. Entry & exit holes right through the center and the hinge taped into place on the inside so that the tape is neatly out of sight and stuck firmly on a large flat area. This would have a much nicer appearance, like a Barret .50 rifle.
Wow that looks awsome! How long does it take for Hoover to create a vacume in the pipe?
sitzikbs3 years ago
Great job guys! it looks awsome!
can it launch a small potato too?
ynze (author)  sitzikbs3 years ago
I never tried...
payman3 years ago
Thanks, this is very interesting...!
mrmath3 years ago
Kinder Eggs are illegal in the US :( I guess you'd have to substitute small water balloons :)
klindner mrmath3 years ago
I read the wiki link. . . and I still don't believe it, I juuust walked out of a VONS 10 minutes ago which carried them. There are also identical Korean and Japanese knock offs at Asian specialty stores all over.

THX for the awesome, and awesome-ly simple, 'ible!
What?! We bought them all the time in Cambridge, MA. Are you serious?
Unfortunately, yes, I am. http://en.wikipedia.org/wiki/Kinder_egg#Prohibition_on_sale_or_import_into_the_United_States
According to QI, they are the most-seized item by Customs in the US.
-Olaf
Wow! I guess what we bought were smuggled in. Now that we live in Prague, we can have all the choking hazards we want. Thanks for the info!
wblack33 years ago
Wow! Looks lots of fun!

Would it work if it used a high pressure air supply (or even the 'reverse' end of a vacuum cleaner) and the Bernouli effect?

Might need a regulator or such to get a stream of air at just the right angle in the launch tube so that it gets the air in the launch tube moving nicely.

Say, having that Y junction closer to the bottom end of the launch tube, so that it sucks the projectile in, then as the projectile passes the Y-junction, it becomes a 'pushing' blow. Might allow it to work without the flap the kids use on the top of the launch tube.

Great project and video, well done!
That would complicate the project too much. I've tried building something like that, and got all kinds of problems.

This project relies on the inertia of the projectile.

The vacuum does all of it's work in the first part of the tube, simply getting the projectile into motion.

The mass of the projectile, combined with it's velocity requires many times more force to change direction than for the air flowing through the pipe. So, when the air gets to the end and changes direction to exit through the Y-section - the projectile continues in a straight line right to the end of the pipe, where it hits the business card.

At the moment the business card gets struck by the projectile, is yet another example of the inertia of a large mass overcoming a smaller mass which is at rest. - The business card gets knocked away, and the projectile continues almost exactly along it's original path.

Trying to utilize a Bernoulli effect, will give a greatly reduced amount of vacuum acting on the projectile. Yet, you can use the other end of a vacuum to make this kind of launcher work. You just need to account for a more complicated feeding of a projectile. If, you were to use a T-fitting with a short section of pipe that is capped air-tight on the 'T', a barrel on one leg of the 'T' and a positive pressure air source such as the exhaust side of a vacuum - Then you could have a round projectile in the stub pipe, if you hold that so the stub is below the barrel nothing will happen. Rotate that so the stub is above, with air flowing and the projectile will roll down into the airflow and get carried down the barrel.

I tried doing this with an electric paintball hopper and had problems with the air pressure keeping the balls from dropping. There were too many leaks in the hopper, and enough air was flowing up the feed tube to push the balls backwards.
axlotleft3 years ago
Looks like great fun, but remember to be very careful of using indoor appliances outdoors where it might be wet. I know someone who was electrocuted using a vacuum on his car in the driveway. A ShopVac would eliminate that worry I think.
unclebill3 years ago
i like the little girls victory dance when it fires.
benduy3 years ago
this works like one of those jet vacuum thingies, air is pushed out, creating a sucking vacuum at the base. we tried with a gas powerd jet, by by pumpkin
dkeeler3 years ago
Great idea!!! I'm thinking this would work AMAZINGLY with a higher pressure shop-vac! hmmmm.... a project for this weekend!!!
ginger200373 years ago
dang it, I knew we threw out the vacuum too soon :(
schaude3 years ago
großartig! der tag für den nachbau dieser "kanone aus einfachen haushaltsmitteln" wird kommen...
Kiteman3 years ago
The better projectiles are longer projectiles - if they are too short, they can get jammed sideways into the side pipe.

I found that the larger size of "Pritt" glue stick fits extremely well, and flew the length of my lab (10m) hard enough to leave a dent in a cupboard door and shatter the stick...

Plus, if you hold the projectile in the end of the pipe for a few moments, you get a slightly harder vacuum form (you can hear the vacuum cleaner's motor change note), and the range increases dramatically.

ynze (author)  Kiteman3 years ago
Well, those are useful tips! Thanks!
Nyxius ynze3 years ago
You should also be able to squeeze a few more feet out of it by using a smaller Diameter tube and projectile. A projectile that 6 times longer than its width, tapered on the end, and slightly nose heavy should also do something for your distance/stability.
ludo3 years ago
Has anyone tried firing small Easter eggs? Wrong time of year to get them, of course...
rayroshi3 years ago
Ha! Those kids look like they're having a ball with that!! Good dad, good job.
qmc3 years ago
Excellent! Got to try this ... got loads of vacuum cleaner spare parts. Thanks for the instructable.
yellow21213 years ago
Wonder how this would work with a rechargeable dust buster, maybe with smaller diameter tube and cross bolt projectiles. Not nearly as kid friendly but an idea.
Hellwolve3 years ago
Very smart work! Quite like what you've made :-)
dewexdewex3 years ago
Of course, you could always take the full bag out of the vac, attach to the end of the bazooka and blow all your crap over the difficult neighbour's fence. ;)
dewexdewex3 years ago
Ha! Way cool!
Silence3 years ago
This is awesome !! :P
I bet you could use a bit of tape and maybe a rubber band or two to make the index card into a self-resetting door...
chrisnotap3 years ago
before I entered the page I thought you were going to use the blower end of the vacuum cleaner but this is even more ingenious!! My hat goes off to you. Brilliant.
AndyGadget3 years ago
 
This is one of those things which just HAS to be tried!
(How about a piece of tape as a hinge to hold the business card to the top of the tube? The resistance to the projectile should be minimal as it flies through.)
I was thinking a short piece of string or lightweight chain, myself.
 
That's even better - No chance of deflection as it leaves the barrel.
 
Dyson, 3 foot (1m) tube firing Pritt stick padded out with duct tape and a coating of olive oil - Around 70ft  (21m) to first bounce. 
Great fun!

Great concept & simple to build. Can't wait to try it out.

I was doing some research on fitting sizes here -
http://www.spearsmfg.com/prod_dimensions_spec/40-4-0511_0511_web.pdf
and it looks like the O.D. of a 3/4" PVC cap is about 1-5/16". (see page 56 of the pdf) 1-1/4" schedule 40 PVC pipe should be about 1-3/8" I.D., so a length of 3/4" pipe capped on both ends could make a decent projectile. This would allow you to experiment with different lengths and weights as you wouldn't need to glue the ends on.

Your local store may not carry that brand, so the dimensions may vary. I usually take my calipers with me when I go to the hardware store. Also, some caps have bumps on the outside that could be easily sanded off if it makes it too big. Conversely, if it's too small, a wrap of tape can add to it.

That pdf file is a gold mine of dimensions for PVC mad scientists! They have more specs on Sch 80 and other products listed here - http://www.spearsmfg.com/product_dimensions_spec.htm

Another mod I'm thinking of is to duct tape the card in place on one side so it hinges out of the way when fired, but doesn't fall off. May work better for rapid fire barrages.

Thanks for posting this. Can't wait to try it out!!!

Vince
kretzlord3 years ago
what if you trimmed a potato down to the same size as your canister? quick and easy potato canon? though hollow plastic egg canisters are much more family friendly. Great Instructible!!!!!
Potatoes would be more ecologically friendly (biodegradeable) if you couldn't find the projectile, though.
ynze (author)  kretzlord3 years ago
Well, it's worth a try!

Thanks!

Y.
gito53 years ago
Simply ingenious!
NE patsrock3 years ago
cool
bell2343 years ago
Wow!
bell2343 years ago
Tnx!
rimar20003 years ago
A-WE-SO-ME, and very clever!
DJ Radio3 years ago
That is totally OG. Best part is that I can easily make this! Thanks for posting!
janw3 years ago
Super Ynze. Echt leuk!
YNZE, The very fact that you do stuff like that with kids tells me you are a real good guy. Way to go! I hope you explain the principles involved as I believe a learning opportunity is a terrible thing to waste. Cool stuff!
ynze (author)  burnerjack013 years ago
Thanks! I'll add an extra step with some of the physics involved somewhere next week.
mikeasaurus3 years ago
Awesome!
ynze (author)  mikeasaurus3 years ago
Thank you, artist in residence.
ChrysN3 years ago
Looks fun.( You are such a cool dad!)
ynze (author)  ChrysN3 years ago
:D Thanks so much for this comment! I will point it out to my kids :D
bgepp13 years ago
vacuum cleaner bazooka???? Say no more - I love it! thanx for making a video
jrh0653 years ago
The simplicity here is amazing! My college dorm-mates will fear me!
Fun for kids.  Easy and cheap to make.  AND you don't have to ruin anything in the process.  Love it!
ynze (author)  AngryRedhead3 years ago
Thanks!