Ready the Cannons!

Build Wiffle Ball Launchers, Beverage Bottle Bazookas, Hydro Swivel Guns, and Other Artisanal Artillery

William Gurstelle

• Publisher: Chicago Review Press
• Year: 2016
• Print ISBN:
  9781613734452
• eBook ISBN:
  9781613734483
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

Garage warriors will get a bang out of this new handbook from the author of Backyard Ballistics that shows how to build cannons and other fun things that shoot, from Wiffle ball launchers and beverage bottle bazookas to superpowered water guns and model culverins. In Ready the Cannons!, engineer William Gurstelle breaks down how to safely construct a dozen awesome artillery devices in your basic home workshops using easy-to-find household or hardware store materials. Clear instructions, diagrams, and photographs illustrate how to build projects ranging from the simple—a supersonic Ping-Pong ball shooter—to the more complex—a replica of the Napoleon Cannon.
With a strong emphasis on safety, the book also gives tips on troubleshooting, tells the history of how and when the artillery devices were used, and explains the physics behind the projects. This book will be indispensable for the legions of backyard watergunners, model-rocket launchers, and fireworks fanatics who wish every day were the Fourth of July.

THE BEVERAGE BOTTLE BAZOOKA

The Beverage Bottle Bazooka is an easy-to-complete project and it’s a real thrill to use. As you build it, you will combine a tad of physics with a smidgen of chemistry to make something quite wonderful. And there’s a bit of ecology in there as well because the project uses some recycled materials such as cardboard tubes and empty plastic beverage containers. (It’s a good way to repurpose and recycle stuff around your house as well.)

HOW THE BAZOOKA GOT ITS NAME

Back in the 1930s, Bob Burns, an American comedian and singer, built a trombone-like instrument out of two pieces of telescoping brass tubing with a whiskey funnel stuck on one end. Burns named his device a bazooka.

When played, the bazooka produces a weird warbling that sounds like a cross between a kazoo and a trombone. Since Burns was such a popular radio entertainer, his contraption also became popular, at least as a novelty, and eventually so did the word bazooka. When Burns first coined the phrase, it was taken to mean any strange, stove-pipe-shaped gizmo.

In the early years of World War II, a group of army scientists were looking for a name for a new type of rocket cannon that they had just invented. One of the engineers in the group suddenly had an idea. He looked over the odd-looking gun carefully and then called out that it looked “just like Bob Burns’s bazooka.” The name stuck.

The new weapon was quickly developed and issued to Allied army forces fighting the German army in Europe. Initially the device had a few bugs, but it was quickly improved through battle testing. Eventually the bazooka became an important part of the army’s arsenal.

This soldier should be wearing safety glasses!

MATERIALS

• General purpose glue or hot glue gun
• (1) 3-inch inside diameter (ID)* smooth-to-female pipe thread PVC adapter
• (1) Thick-walled cardboard tube, 3-inch ID, 4 feet long
• (1) 3-inch male pipe threaded plug
• (1) ½-inch PVC pipe, 5 inches long
• 18-inch length of two-conductor 18-gauge speaker wire
• (1) Two-hole rubber stopper, small enough to fit inside the beverage bottle
• Electrical tape
• (1) Piezoelectric gas grill replacement igniter^†
• (1) 1-inch square wood dowel, 4 inches long
• (1) 2½-inch steel corner brace
• (2) 4-inch diameter hose clamps
• Bottle of rubbing alcohol
• 2- to 2½-inch diameter, 10-inch long empty and clean plastic carbonated beverage bottle^‡

TOOLS

• Drill and ¾-inch wood drilling bit
• Wire clipper/stripper
• Screwdriver
• Safety glasses

BUILD THE BEVERAGE BOTTLE BAZOOKA

1.1 Beverage Bottle Bazooka Assembly

1. Apply glue to the interior of the 3-inch diameter threaded PVC adapter. Push the adapter onto the end of the cardboard tube. Allow the glue to dry.

2. Drill a 7⁄8-inch diameter hole in the center of the flat part of the threaded plug. Insert the ½-inch PVC pipe through the hole until it extends approximately halfway in. Glue the pipe into place using glue or hot glue and let dry.

3. Strip off ½ inch of insulation from both ends of both conductors of the speaker wire. Insert the speaker wire into the ½-inch pipe until it exits the other end.

4. Pull apart the conductors for two inches from both sides of the speaker wire. Insert one conductor through each hole in the rubber stopper. Then push the rubber stopper firmly into ½-inch pipe as shown in diagram 1.1. Use electrical tape to keep the exposed copper wire in the conductors extended from the end of the stopper and separated by about 3⁄16 of an inch.

1.2 Igniter Detail

5. Drill a hole slightly larger than the diameter of the body of your piezoelectric igniter in the middle of the square wooden dowel as shown in diagram 1.1. (This is typically about ¾ inches, but check before drilling.) Insert the igniter into the hole and glue.

Use two of the screws that came with the steel corner brace to attach the brace to the square dowel. Check diagram 1.1 for the correct orientation.

6. Most replacement piezoelectric igniters come with a wire connector harness. One end of the wire connector harness connects to the electrodes and the other end connects to the spark maker on the grill. For our purposes, we do not need that grill hardware. So simply insert the wires into the appropriate electrode connectors on the piezo igniter and then use a wire cutter to cut off the unneeded grill spark-making hardware. You can discard the unneeded hardware.

1.3 Trigger Detail

7. Make wire-to-wire connections between the speaker wires’ exposed conductors trailing from the ½-inch PVC pipe as shown in diagram 1.4. Wrap the connections with electrical tape.

1.4 Igniter to Spark Gap Connection

Test the device by pressing the button on the piezoelectric igniter. If you’ve done everything correctly, you should see a spark jump between the two exposed conductors. If you don’t see a spark, check the spark gap for width, review diagram 1.4, and rewire as needed.

1.5 Spark Gap Detail

8. Use the hose clamps to attach the piezoelectric trigger to the bazooka body.

1.6 Beverage Bottle Bazooka

Using Your Beverage Bottle Bazooka Safely

Be aware that your bazooka packs a mighty wallop! While I’ve never had any trouble, as always, your safety is important, so:

• Wear safety glasses (and if your ears are sensitive, ear plugs).
• The bazooka can shoot empty plastic bottles more than 100 feet. Clear the area in front of breakable objects. Never aim the bazooka at anything you don’t want to hit.
• Be careful with rubbing alcohol. It is flammable.
• Inspect the bottle after every firing and discard when it becomes worn.
• Always obey local laws and regulations. Check with authorities prior to using if you’re unsure about this project’s legality in your area.

READY, AIM, FIRE

1. Place a ½ teaspoon of fresh rubbing alcohol in the beverage bottle. Shake the bottle vigorously with your hand covering the mouth of the bottle. Remove your hand and shake out any excess liquid alcohol.

2. Add air back into the bottle by waving it forward through the air four or five times with the bottle mouth uncovered.

3. Quickly insert the bottle onto the ½-inch pipe connected to the threaded plug.

4. Securely screw the plug into the threaded adapter.

5. When ready, press the button on the igniter. Instantly, the alcohol in the bottle will ignite, causing the bottle to rocket forth from the bazooka with amazing energy.

Enjoy your work!

HOW THE BAZOOKA WAS INVENTED

Prior to World War II, the only way to stop a tank was to blast a hole in it with a large cannon. That meant that armored tanks were pretty much invincible to anything an unarmored infantry platoon could throw at them. But in late 1940, a Swiss engineer named Henri Mohaupt designed a new type of bomb. His invention was an explosive shell that focused the blast into a narrow point of energy capable of penetrating thick armor. It was well adapted to use against armored vehicles because unlike the antitank ammunition shot from cannon barrels, Mohaupt’s antitank grenade ...

Table of contents

• Cover
• Title Page
• Copyright
• Contents
• Introduction
• Staying in One Piece
• 1 The Beverage Bottle Bazooka
• 2 The Hydro Swivel Gun
• 3 The Mack-Mack Gun
• 4 The Little Corporal Cannon
• 5 The Tempered Steel Rubber Band Shooter
• 6 The Shape Gun
• 7 Cast Metal Cannonry
• 8 Mushroom Cloud Cannon
• 9 Slingshots, High and Low Tech
• 10 The Near-Supersonic Ping-Pong Ball Launcher
• 11 The Wiffle Ball Launcher
• Appendix 1—Materials
• Appendix 2—Find out More