Young Engineers: Pyramid Catapult - Easy and Powerful DIY STEM Project for Kids

Summary

In this video, Lance demonstrates how to build a sturdy and effective pyramid catapult using simple materials like craft sticks, skewers, masking tape, and rubber bands. The step-by-step guide includes constructing triangular frames for strength, assembling the catapult arm with skewers and a straw hinge, and attaching a cup for launching projectiles. The video explains the science behind the catapult's performance, highlighting the strength of triangles and the importance of arm length for launching projectiles farther. Viewers are encouraged to experiment with different projectiles and modify the design for improved performance.

Takeaways

• 😀 The pyramid catapult is sturdy, easy to build, and effective, functioning just like any other desktop catapult.
• 😀 Start by creating three triangles using craft sticks and tape to form a strong, stable frame.
• 😀 The frame is assembled into a pyramid shape, which is reinforced with masking tape for added strength.
• 😀 The catapult arm is made by taping three 12-inch skewers together and reinforcing it with a craft stick in the center.
• 😀 A piece of straw is used to create a flexible hinge for the catapult arm, allowing it to pivot during launches.
• 😀 The rubber band provides tension, powering the catapult arm to launch projectiles.
• 😀 A cup is attached to the end of the catapult arm to hold the projectile during launch.
• 😀 Experimenting with different projectiles can affect the performance of the catapult, such as distance and accuracy.
• 😀 The pyramid frame is strong because triangles distribute force evenly and resist flattening compared to squares.
• 😀 The catapult arm's length increases the speed of the projectile, with a longer arm launching projectiles farther.
• 😀 Adding more rubber bands can increase the power of the catapult, but it may require reinforcing the frame for extra support.

Q & A

What makes the pyramid catapult design sturdy?

The pyramid catapult is sturdy due to its triangular frame. Triangles are a strong shape because they distribute force evenly and do not easily change their shape when under compression.

Why is the pyramid shape used in the catapult's frame?

The pyramid shape is used because triangles provide structural stability and strength. Unlike squares, which can flatten under pressure, triangles maintain their shape and distribute force evenly.

How does the length of the catapult arm affect its performance?

The length of the catapult arm affects how far the projectiles can be launched. A longer arm moves faster at its outer end, increasing the speed and distance of the projectile. This happens because points farther from the fulcrum move faster than points closer to it.

What is the role of the straw in the catapult's design?

The straw acts as a hinge for the catapult arm, creating a flexible and sturdy point of rotation. It helps in smoothly transferring energy to the arm, enabling it to launch projectiles effectively.

What happens if the catapult's frame is made from squares instead of triangles?

If the frame is made from squares, the shape can easily distort under pressure, flattening out into a diamond. This compromises the strength and stability of the frame, making the catapult less effective.

How does the rubber band contribute to the catapult’s operation?

The rubber band provides the necessary force to launch the projectile. It is stretched and then released to propel the catapult arm, launching the projectile with speed and force.

What should you do if your catapult isn't launching projectiles far enough?

If the catapult isn't launching projectiles far enough, you can add more rubber bands to increase the tension. This will provide more force to the arm and increase the launching distance. You may also need to reinforce the frame with additional tape for added sturdiness.

What kind of projectiles should be used with the pyramid catapult?

Foam cubes are recommended because they are lightweight and safe for experimenting without causing damage. However, the size, weight, and shape of the projectiles can greatly affect the performance, so experimenting with different projectiles is encouraged.

Why does the project mention experimenting with projectiles?

Experimenting with different projectiles allows you to observe how factors like density, shape, weight, and size can impact the performance of the catapult. It helps fine-tune the design for better launching results.

What is the best way to attach the cup to the catapult arm?

The best way to attach the cup to the catapult arm is by taping it securely with a piece of tape. Make sure to leave some space behind the cup to grab the arm and pull it down to launch the projectile.