Play Catapult

Making a miniature catapult out of a rat trap is a fun project. There are many variations on how to make a rat trap catapult, from the extremely simple to the ridiculously elaborate, so you can have fun making your own model at any level. Despite the small size, rat trap catapults pack a surprising amount of force and power with each throw.

Instructions

1 Cut out the 10-by-10-inch base from the one-half-inch plywood with a saw. Sand the edges and corners of the base until they are smooth. Paint the surface of the base if you want.
2 Remove the projectile arm and the bait holder from a rat trap by pulling it off with the pliers. Discard these pieces; you will not need them anymore. Keep the spring mechanism on the rat trap.
3 Place the lever spring mechanism in the relaxed position. Tape the plastic spoon in a downward position to one side of the lever arm. Use plenty of duct tape so that the spoon is securely fastened to the metal.
4 Screw the rat trap onto the large wooden base. Place the screws in areas where they will not interfere with the spoon, the lever or the spring mechanism.
5 Hammer a nail into the wooden base on the side. This nail will be used to wrap the string around to hold the catapult down in the loaded position.
6 Tie a piece of string to the lever mechanism in the center. Use the string to pull the lever back so the spoon is now facing up. Loop the string around the nail to keep the catapult in the loaded position.
7 Hammer the eraser to the rat trap base right under the position that the lever arm will slam into once the string is released. The eraser allows the lever arm to be angled in the proper trajectory.
8 Place the projectile on the spoon and release the string. Watch the projectile fly.

Catapults are an old-fashioned war device that was designed to launch objects over the walls of a fort or castle. If you are teaching children about Medieval history, make the lessons more exciting by having the kids create their own catapults out of craft supplies. Use them to launch small objects, such as paper balls, coins or erasers, across the classroom when the children finish building the catapults.

Instructions

1 Arrange three craft sticks into a triangle on a table top and tape the sticks together with duct tape at the corners. Make all of the craft sticks the same length and position them flat against the table before taping them.
2 Repeat this process two more times so that you have three craft stick triangles.
3 Tape together two of the triangles along one edge. This allows the triangle pair to open like a book.
4 Open the triangle pair to a 60-degree angle and slide the third triangle into the opening perpendicularly. Rest the third triangle flat against the table as you insert it between the other two. Tape the triangles together at all abutting sides.
5 Place a singular craft stick into the corner where all of the triangles meet and tape it into place so that the craft stick rests at a 120-degree angle.
6 Wrap a rubber band around the craft stick and the top of the triangular structure.
7 Tape a small paper cup, bottom down, onto the end of the singular craft stick. Place an object into the paper cup. When you pull it back and release it, the object flies across the room.

In medieval wars, the catapult was one of the great equalizers when enemy forces locked themselves inside castle walls. Able to hurl stones over high castle walls, a catapult provided an early means of bombarding a town or fortress. You can build a working small-scale catapult model to add to your home arsenal.

Instructions

1 Cut two balsa wood blocks to 5 inches long and two others to 6 inches long. Lay them in a square. Tap two nails into each corner to secure the parts. This is the catapult base.
2 Stand two 6-inch balsa blocks vertically on one side of the catapult base. Hammer two nails through the bottom of the base and into each vertical block. Brace the free ends of the two vertical blocks by adding another horizontal block between them. Hammer two nails into each joint where the blocks meet. This will be the catapult front.
3 Cut a dowel to fit between the two vertical beams of the catapult front. Set it between the beams, about halfway between top and bottom, and secure it with one nail through the center of each end. This is the catapult pivot.
4 Cut two 5-inch balsa blocks. Use the whittling knife to cut the block ends to 45-degree angles. Fit the blocks on the catapult sides so that they brace the catapult front's vertical beams. The braces should be at approximately 45 degrees. Hammer two nails into each end of both braces.
5 Cut a 7-inch balsa wood block. Whittle a concave "cup" into one end of the block. Hammer a nail into the block just in front of the cup. Use the needle-nose pliers to bend the nail into a hook shape, pointing toward the cup. This is the catapult arm.
6 Attach the catapult arm to the pivot on the front of the catapult with a nail. Loop a rubber band around the front's top brace, then attach the other end to the hook on the catapult arm. You should be able to pull the arm down and launch a marble or similar small objects.

Creating small catapults is an exotic hobby that many people enjoy. Use these catapults to play a game. This one requires three dart boards and marshmallows. The goal is to score points by launching the marshmallows at three dart boards. The dart board farthest away will be worth five points. The closest dart board will be worth one point. The middle dart board will be worth three points. You must score exactly 21 points. Go over by any amount and you will automatically go back to having 14 points. Each player fires twice per turn.

Instructions

1 Place a dart board 15 feet away.
2 Set up another dart board 10 feet away.
3 Place a third dart board five feet away.
4 Place a marshmallow in your miniature catapult and fire it at the dart boards.

Catapults are an ancient device that were used to hurl objects over castle walls or barricades. When teaching students about medieval or ancient history, it can be exciting to show them how to create their own catapult out of simple craft materials, such as paper towel rolls.

Instructions

1 Cut open 10 paper towel tubes vertically with scissors.
2 Roll each tube up again tightly, and tape it with masking tape. This will cause the rolls to be more sturdy and they won't bend when you launch objects with your catapult.
3 Tape the corners of three of the rolled tubes together so that they form a triangle.
4 Repeat this process two more times until you have three paper-towel-roll triangles.
5 Place two of the triangles together horizontally, and tape one of the sides.
6 Splay open the connected triangles, and insert the third triangle into the space that is opened up. This will create a paper-towel-roll pyramid.
7 Tape all of the sides of the pyramid.
8 Place the end of the remaining paper towel roll into one of the bottom corners of the pyramid. Tape it into place. This will allow the arm to remain attached to the structure, while enabling it to be moved backward in order to hurl an object.
9 Tape a small paper cup to the end of the paper towel tube arm with the cup facing upward.
10 Loop a rubber band around the paper towel arm with the cup.
11 Loop the same rubber band around the top of the pyramid.
12 Tape the bottom pyramid to an 18-inch square of cardboard in order to stabilize it during use.
13 Place an object into the paper cup, pull the cup back, and release the cup to launch the object into the air.

In the ancient and medieval periods, catapults were used as siege weapons, capable of hurling projectiles such as boulders, flaming barrels of pitch or even beehives at enemy fortifications and cities. There were several types of catapult, some of which used counterweights and others that used torsion to store potential energy. Because the mechanical principles of the torsion catapult are simple, it's easy to make a small-scale replica that resembles the original and really works.

Instructions

1 Cut parts for your catapult out of wooden rod and sheet using a craft knife or saw. You will need two long sections to form the base of the catapult, a throwing arm and five short sections. You will also need two triangular supports cut from a flat wooden panel. The throwing arm should be five-sixths of the length of the base pieces. If your base pieces are a foot long, for example, the arm should be 10 inches. The short sections should be half the length of the arm, and the triangular supports should be slightly taller than one of the short sections.
2 Scrape the wooden sections with a wire brush to weather them. You may wish to stain them to give them a darker appearance.
3 Attach a short section to one of the base pieces at right angles. The upright should be a short distance from the forward edge of the base piece. Use wood glue to hold the upright in place. Repeat this process for both base sections.
4 Screw or nail a triangular support to both the upright and the base section, connecting them and adding extra rigidity. Again, do this for both base pieces.
5 Glue two short sections between the base pieces. They should be attached to the underside of the bases at the front and rear.
6 Insert the final short section as a crossbar by gluing it to the rear of both uprights at the top.
7 Drill a hole in the base sections. The hole should be as large as you can make it without damaging the base. Position the hole slightly to the rear of the uprights, and make sure the two holes are aligned.
8 Drill a hole in the end of the throwing arm. It can be smaller than the holes in the base piece.
9 Cut a length of string or twine. The exact length will vary depending on the thickness of the string and the size of the catapult. A foot-long catapult can need up to 30 feet of string. Tie a length of heavy wire, like coat hanger wire, to the end of the string.
10 Tie the opposite end of the string to a length of dowel. Using the wire like a needle, thread the string first through the hole in one base piece, then through the hole in the arm, then out of the hole in the opposite base piece. Wrap the string around another length of dowel and thread it back through the hole, repeating the process in reverse.
11 Repeat this process until the string is used up or can no longer fit through the holes. After the first three or four passes, you no longer need to thread the string through the hole in the arm. Instead, pass it behind the base of the arm on the first pass, then in front of it on the return until the arm is wrapped tightly between two layers of string.
12 Build a basket to hold your projectile, using scrap wood or cardboard. You can glue or pin this to the upper surface of the head end of the throwing arm.
13 Insert a screw hook into the head end of the throwing arm. Insert hooks into the base pieces so that they line up, then depress the throwing arm and run a length of wire through all three hooks. To launch the catapult, load the projectile into the basket and pull the wire out.

The ancient Greeks used catapults to hurl projectiles, such as large rocks, at their enemies. The most simple catapult requires two mechanical parts: a lever and a spring. You can make your own catapult out of a paper clip and other office supplies you probably have in your desk -- even if it will not fire a stone over a rampart, Use it to fling wads of paper at an opponent or to teach a child about levers and springs.

Instructions

1 Look at the paper clip. Each clip has an outer loop of wire and an inner loop of wire that is formed with an end of the wire. Grasp the top of the loop of the inner ring and pull it out so that it stands at about a 45-degree angle from the outer ring. The large loop forms the base of your catapult while the smaller loop makes the arm.
2 Bend a holder into the catapult. Arrange the paper clip so that you look at it with the arm in the air and pointed away from you. Grasp the end of the wire that forms the inner loop with needle-nosed pliers. Bend it 90 degrees inward to close the loop. Now grasp the wire halfway between the bend you just made and the top of the loop. Bend it toward you so that a section of wire in the shape of an "L" stands away from the arm. This forms the frame for your projectile holder.
3 Cut a strip of cardboard slightly wider than your paperclip catapult and about half the length of its base. Bend the strip of cardboard in half lengthwise, then place it so that it rests on the frame for your projectile holder. Half of the strip should rest along the top part of the arm, while the other half should rest on the "L" shaped piece of metal that sticks out from the arm. If cardboard is unavailable, you can use a piece of plastic or a strip of tape folded over on itself with the sticky side on the inside of the fold.
4 Attach the cardboard strip to the catapult with two strips of tape. Use one strip to attach it to the top of the arm of the catapult and one strip to attach it to the frame for the projectile holder. Place a projectile, such as a wad of paper, in the projectile holder and hold down the base of the catapult. Pull back the arm toward the base; then release it to fire your new catapult.