Our group is prompted to design a hover landing craft which can flow both on land and water. The hover landing craft was designed to suspend above the ground with the power of wind. We were expecting that the wind produced by the motor attached to the body would give it the power to move forward and hover landing. We put our ideas on the first sketch with one motor, one hole ( surrounding the motor ) and one body.

Originally, we made the first model using the hardboard. Different from the sketch, we added one more motor on the body, aimed to balance the force of rotation resulting from ONE motor. Two holes surrounding the motors run across the body  so that the air flowing in from the front would be able to change direction to the bottom. With the wish of getting more force to lift the craft at high speed, we designed two wings on the sides. What’s more, taking the ideas from the airplane, we also put vertical stabilizer and horizontal stabilizer at the end of the body. In this way, the craft is able to change its direction vertically and horizontally with the help of servos. Then, as you see the picture, it’s exactly our hardboard hover landing craft (without motors attached).

Our second iteration was somehow similar to the hardboard model. More specifically, for a further step we designed the holes which are assumed to be the most important part. We attached the motor to the thin wood material joined at the front of the hole. At the very beginning, we believed that a cylinder hole would be much better, regarding to the cool appearance and its function of air flowing. Apart from this, a cylindrical hole with a curve to change the air flow direction would lead to less power loss, serving as a constant and steady power source. To make it more flexible, we gave up the former design of a single, closed hole. We were expecting to take almost everything into control, including the wind flow. So, the board is bound to the first choice. With the board rotating around the axis attached to the end of the hole, we are able to control the air flow direction. As you can see from the 3-D model on Rhinoceros, when the circle shaped board rotates to the horizontal direction, all of the wind flows directly backward. In such a case, the craft is able to get one hundred percent of power in the forward direction. Otherwise, when the board closes, rotating to the vertical direction, all of the wind is re-direction to the bottom, runs through two holes under the body and finally hits the ground. With the back force from the ground, the hover landing is created. We used glue to join the foam board. All of the parts were created on laser-cutter instead of 3-D printer, thinking that the 3-D printed material would be much heavier. However, after testing , we found that even the full power is not enough for hover landing when the board closes so we had to change the design.

We searched the Internet for precedents and started to conduct our third iteration. We hoped to add an air bag at the bottom to gather the wind. To make the wind in the bag flow out in different directions we used cardboard slices to distribute the air flow to the holes cut into the bag. Considering from a realistic point instead of an ideal perspective, we left the horizontal stabilizer, remaining the vertical one while the HIGH speed was NOT what we had expected…so sad. We did the test again and it do hover landing however, it couldn't move forward. When the flap is half open, the hovercraft cannot make enough lift to fly forward.

In the end, here comes our final iteration. To fully use the wind power, we dropped the former complicated design. To decrease the whole weight, we applied foam board to serve as the body. Two big circles are cut on the hot wire cut according to the size of the propeller. We used two motors, the one facing totally downward and the other facing backward at a small angle. Two propellers are rotating in an opposite direction to counteract the rotation force given by the rotating propeller. In this way, the craft is able to hover landing and move forward, at a very high speed. To change the direction, we attach a vertical stabilizer controlled by a servo at the center of the hoverboard. We use laser cutter to get the motor mounting plates from thick wood in order to  attach the motors. All through the process of the project, we took the control of motors and servos with the program written on Arduino