WALT: We are learning to design, build and improve a working hovercraft by using scientific and engineering principles, testing variables and working effectively as a team.
Today, we had Jess as our teacher. Our group was assigned to build a hovercraft from scratch using only a few materials. Our challenge was to create a working hovercraft that could glide smoothly across a surface while meeting specific performance requirements.
A hovercraft is a unique amphibious vehicle that glides over smooth surfaces by trapping a cushion of high-pressure air beneath it. Our group was tasked with building a working prototype of a frictionless transport vehicle using only a recycled CD, a sports bottle cap and a balloon. Our mission was to maximise hover time and distance while keeping the hovercraft stable. To meet the challenge requirements, our hovercraft needed to glide for at least 1.5 metres and hover for a minimum of 5 seconds.
To build our prototype, we gathered one old entertainment CD, one sports drink pop-top valve cap, a standard 10-inch rubber balloon and a hot glue gun to create an airtight seal. When we blew up the balloon, air became trapped inside it, creating pressure. Opening the valve released the air downwards beneath the CD. This created a cushion of air between the CD and the ground, reducing friction and allowing the hovercraft to move more easily. As the air escaped around the edges, our hovercraft was able to glide across the surface.
During our initial testing, our group faced a major engineering problem. The hovercraft immediately tipped to one side, leaked air quickly from the base and began spinning instead of travelling in a straight line. We worked together to inspect the vehicle and discovered that there was a tiny gap in the hot glue around the bottle cap. We also noticed that the balloon was sitting slightly off-centre, making the hovercraft unbalanced. We fixed this by re-gluing the seam to create a better airtight seal and repositioning the balloon so the weight was more evenly distributed.
Overall, our hovercraft challenge taught us that small changes can have a big effect on how an engineering design performs. Testing different balloon sizes helped us understand how the amount of air affected both hover time and distance. We also learned that teamwork, problem-solving and improving our design after testing are important parts of the engineering process.