The strength of a thrower can be defined as its sturdiness and reliability when used, or the power of throwing an object. Therefore, knowing how to make a catapult shell can really help you understand how to make a sturdier catapult, and to be able to propel an object farther and stronger. Using basic engineering principles, you can make your own large or smaller catapults.
Step
Part 1 of 4: Preparation of the Thrower
Step 1. Prepare tools and materials
To ensure that you make the highest quality and safest thrower, use a material that is durable and strong enough to withstand enormous force when ejecting an object. Many good quality materials can be used to make a catapult, but at the very least you will need:
- Broom handle or crank (turning device)
- Coating/filling material
- Plywood or plywood board with a thickness of 0.5 cm – 1.25 cm (1/4 inch – 1/2 inch), made measuring 37.5 cm (15 inches) wide, 45 cm (18 inches) long and 1, 25 cm (1/2 inch)
- Rope (strong, preferably elastic, such as a kernmantle rope)
- Screw or bolt
- Scales (optional)
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Wood (better to use wood that does not bend easily, such as oak)
If using a 2x4 board, prepare: 2 91.5 cm (36 inch) long boards, 1 76 cm (30 inch) long board, 4 38 cm (15 inch) long boards and 1 46 cm (18 inch) long board
Step 2. Calculate the base and its weight
Throwers use a lot of force to throw loads, so you need a solid, solid base for a solid and stable foundation. Weak foundations can miss your aim or cause damage to your launcher.
Torsion catapults, which is the technical name for ordinary catapults, have long been made with heavy, reinforced sides, so they can be used for heavier loads, greater pulling force and more stability
Step 3. Cut the plywood board as a support
For the base of the catapult, you will use a 2x4 board supported by triangular plywood. To make the backing board, take one plywood board 0.5 cm – 1.25 cm (1/4 inch – 1/2 inch) thick, 37.5 cm (15 inch) wide, 45 cm (18 inch) long., and 1.25 cm (1/2 inch) high, then cut them diagonally to form 2 equal triangles.
Step 4. Choose the right material for the ejection arm
Traditionally, spruce wood is used as a material for making throw arms because this type of wood is light and strong. Consult a local wood shop near you to see if this option is affordable, and if not, ask for some other material alternatives, two of which are:
- Thick PVC pipe
- Metal pipe (lightweight, durable)
Step 5. Cut the twist lever
You will need a loop of string to generate ejection for your catapult. The more turns, the greater the twisting force (moment), the more power your thrower will have. The number of turns you can achieve is limited only to your strength and the strength of the materials you use to make the thrower. To make the lever loop, take a broom handle and cut it into 2 halves of 38 cm (15 inches) each.
Part 2 of 4: Creating the Basic Part
Step 1. Prepare the right side of the base of your catapult
Position the 2x4 board, 91.5 cm (36 inches) long, horizontally on your workbench or elsewhere with a firm surface. Lay the 2x4 board 46 cm (18 in) at an angle to the 91.5 cm board at a distance of 38 cm (15 inch) from the end of the 91.5 cm board, then attach the two boards using screws.
Step 2. Glue the triangular plywood
Place this triangular plywood on a 2x4 board. The 46 cm (18 inch) piece of plywood is placed vertically to the 91.5 cm (36 inch) board, the bottom is parallel to the 91.5 cm (36 inch) board, and the diagonals will reach approximately both ends of the board. 2x4. Secure the triangular plywood to the 2x4 board using screws. This section forms one base leg on your catapult.
Step 3. Place the left side of the base of your launcher and add a triangular plywood
In the same way as when you made the right side, place a 2x4 board measuring 91.5 cm (36 inches) and 46 cm (18 inches) perpendicularly at a distance of 38 cm (15 inches) from the long end of the board, and attach the plywood. Triangle the two ends of the 2x4 board using screws, with the bottom parallel to the 91.5 cm (36 inch) 2x4 board.
Step 4. Connect the base of the left and right sides
Connect the two sides using two 38 cm (15 inch) 2x4 boards, then secure with screws, the bottom of the triangle and the bottom of the 2x4 board measuring 91.5 cm (36 inches) forming the bottom, while the diagonal part of the triangle at the top. Use long screws to make sure your frame is sturdy enough.
Do not use nails for this part. Nails are sensitive enough to the pressure your catapult will apply to them, so they will loosen and fall off over time
Part 3 of 4: Making the Arms
Step 1. Straighten the base of your catapult
Once your basic outline is complete, you'll now start creating the ejection arm. The top of your catapult will have a 46 cm (18 inch) vertical plank pointing straight up and a 91.5 cm (36 inch) long plank that is level at an angle.
Step 2. Put the screws on the support board crosswise between the two sides
At the top end of the 46 cm (18 inch) vertical plank, place another 46 cm (18 inch) of board between the ends to create a transverse support, then secure with screws. The top of the transverse supports should be flush with the top of your vertical plank.
Step 3. Prepare the sleeves
Take a 2x4 board that is 76 cm (30 inches) long and measure it 6.35 cm (2.5 inches) from one end. Drill holes with a thin side drill in the center, 1.25 cm (1/2 inch) each from the top and bottom, punching holes through the sides in front of them.
Step 4. Add a cup or throw basket
Attach a plastic cup to the center of the flat side of the 2x4 board using screws. This side should be opposite the side where you made the hole through the width of the board. You are free to try other materials and containers, such as baskets, bowls and a box.
Step 5. Make a hole in the base of the frame
Make a 2.54 cm (1 inch) hole on each side of the base of the frame through the triangular backing board. This hole is 15.24 cm (6 inches) from the end of the 91.5 cm (36 inch) plank, which is also the end of your triangular plywood. Then measure 6.35 cm (2.5 inches) from the bottom edge to the top, then drill holes.
Step 6. Give padding on the sleeves
Your ejection arm works by being pulled or pulled back after applying pressure to the rope that will be tied through the underframe. It's a good idea to add cushioning where the ejection arm collides with the transverse support board, as is a blanket or multiple layers of torn cloth. This will prevent damage to your catapult when the ejection arm is pulled back, released, and collided with the transverse support board.
Part 4 of 4: Tying the Arms
Step 1. Tie the rope
You will need approximately 50.8 cm (20 inches) of rope to attach the catapult. Tie the string to the lever of your broom handle, thread the rope through the hole on the right side of the frame's base, then thread it through the hole you drilled in the eject arm, exiting in the opposite direction from the base of the frame and back out onto the second broom handle lever. Wrap it around the second lever, then reinsert it into the frame towards the first lever, where you will wind the rope again. Do this step several times.
- When choosing a rope, look for a material that is strong and elastic. A kernmantle rope, like a parachute rope, is the best option.
- Wrap your rope back and forth over the base of the frame and ejection arm a few times to make sure you have it securely attached to your ejector frame.
- No need to tie the rope tightly. When you turn the lever, the loop of the rope tightens and creates an ejection force.
Step 2. Wrap the rope up and down
After you've looped the rope through the base of the ejector and the ejection arm a few times until it's tight, start wrapping the rope around the second lever, wrapping the end of the rope around the second lever through the loop that goes through all the holes in the frame and the "bottom" of the thrower arm, through the holes on the sides. the other to the loop of the rope on the first lever. Continue this twisting motion, using the top loops on the eject arm along with the bottom loops, each of which passes through the base frame.
- The twist of this rope should be shaped like a figure eight, so that the interweaving of the rope can be seen clearly. The more loops you add through the coils in an up and down motion, the greater the pressure and the more force your thrower will have.
- Once you've tied your rope to the thrower arm and base frame, you shouldn't continue to thread the rope through the thrower arm. To achieve the pressure needed to throw an object, you'll need to thread the rope through the holes in the base frame, wrap it around the broom handle lever, then "up" and "down" the ejecting arm.
- Make sure that your loop of rope stays attached to the broom handle lever.
Step 3. Tie the end of your loop of rope to the side of the thrower arm
When you reach the end of the loop, wrap the rope around the strands on one side of your thrower, crossing them and doing the same on the other side. Now that you can knot the ends of your rope, the added advantage of knotting them neatly is that your knots won't come loose.
Step 4. Add a catch for your thrower arm
When you turn the rope lever, the twist of the rope will cause your throwing arm to move up until the pressure causes the throwing arm to collide with the crossboard. First, let the eject arm fully return to the eject position and estimate the best place to attach a catch, then drill a hole and insert the hook.
By adding a catch to the finish line of your baseframe, you don't have to pull back on your throwing arm to release the weight. You just need to unhook the catch after applying pressure, and your eject arm will shoot forward, stopping on the crossboard and throwing the weight you placed on the eject arm
Step 5. Get your catapult ready and make a spin
Now your turning lever is level on each side of the catapult base, parallel to the 91.5 cm (36 inch) plank, added to the base frame and ejecting the eject arm using the rope. Turn the turning lever to make a twist in the loop of the rope. This spin will put pressure on the catapult, you just need to apply weight to the ejection case, turn the crank handle of your broom, release the catch and fire.
Tips
- Make the angle of the arm when releasing the load equals 45 degrees from the ground, unless the ejection arm is released above the ground. For example, if the load is released at a height of 1 meter (3.3 ft) above ground level, the best angle is 44.6 degrees. This optimal angle will decrease as the thrower height increases.
- The triangle is the perfect support shape to strengthen your thrower. The strongest ones are equilateral triangles, so if you make the thrower and the thrower unstable, add a triangular support.
Warning
- Store this device in a safe place; children who play the thrower unsupervised can be a danger to themselves and others.
- Keep your face away from the swing of the thrower arm.
