Introduction: How to Make Vortex Cannons

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Here are two Instructables in one! Shoot rings of smoke across a room with the Tub Thumping Cannon and the Barking Tube Cannon. Watch me build them and the test results. From MAKE MAGAZINE Volume 15

Step 1: Tub Thumping Cannon

This one is so easy to make and gives great results. You will need a fog machine to generate the rings for both of these projects.

What You Need...

1. 32 Gallon Plastic Trash Can
2. Heavy Duty Trash Bag
3. Golf Ball
4. 2 Bunjee Cords
5. Tape
6. Box cutter.

Step 2: Build It...

1. Using the box cutter, cut out a 6" hole in the bottom of the trash can. Many trash cans have re-rounded circles you can use as guides.

2. Cut out a piece of trash bag a little bit larger than the top of the trash can. Roll up the golf ball in the middle of the bag and secure it with a small bunjee cord. Run a longer bungee cord through the smaller cord.

3. Secure the trash bag to the trash can using tape and attach the longer bunjee cord strap ends to the trash can handles.

Step 3: Use It...

Fill your new Vortex Cannon with smoke, pull back on the bungee/ball handle and let it rip! You should get a nice ring of smoke that shoots across the room. Try a larger hole in the trash can for a larger ring. You've just built the Tub Thumping Cannon! Now on to the Barking Tub Cannon...

Step 4: The Barking Tube Cannon

This Vortex Cannon uses sound waves to generate the smoke rings. This concept was inspired by Bill Beatty.

What You Need...

1. 12" cardboard concrete form tube available at home improvement stores.
2. 12" Woofer/Speaker
3. Thin piece of plywood
4. Cutting tool to cut a circle and tape.
5. Audio amplifier and laptop
6. Tone Generating Software

Step 5: Build It

1. Start by cutting the tube down to about 24". (I learned the hard way that you need a shorter tube as you saw in the video)

2. Using the tube as a guide, cut out a piece of plywood the diameter of the opening of the tube. and tape it to the bottom of the tube. Then cut out a 6" hole in the center of the plywood.

3. Securely tape the speaker to one end of the tube.

4. Wire your audio amp to the speaker and install the Tone Generating software on your laptop.

Step 6: Use It...

You should adjust the Tone Generating software to play a low-frequency saw tooth tone which will 'bump' the woofer and kick enough air to create your computer controlled smoke ring. You can also try different size holes in the tube and different tones and even music for different vortex effects! This is a fun science project and some have been made that really "kick air"! Check out this video. Hope you enjoyed this Instructable.