Fall 2012 - studio 3/4

In this studio, we were tasked with designing and building a remote control airplane. We designed The Dropper, a plane that can hold and drop cargo. Within its lightweight balsa wood, trussed frame, It has a storage compartment connected to a servo motor, so that its contents can be remotely dropped while flying. It steers using servos attached to flaps, using rods, on each of the wings, and a servo attached to the rudder on the vertical stabilizer on the back of the plane. All the servos are connected to an arduino micro controller on the plane, which wirelessly connects to a remote controller that is operated by the user.

 In order to build the plane, we learned about what factors allow a plane to fly, such as its center of gravity, angle of attack, mass, and lift. While designing our plane, we calculated that we would need large wings (~1.5 meters each) to have our plane be able to fly with the propeller that we had, and our heavy cargo. For the wings, we designed and cut an efficient airfoil, which we simulated using a wind tunnel. 

 The third session of NuVu Studio’s first trimester was about designing and constructing remote-controlled airplanes. The main coach that taught the session was David Wang, an engineer who is getting his PhD in artificial intelligence at MIT. For the first few days of the two-week session, David covered the key things that the students needed to know in order for their airplanes to fly, such as there needs to be: 1) lifting elements and there has to be a larger lift than weight; 2) horizontal and vertical stabilizers so they do not flip over; 3) an energy source; and 4) a way to control the plane.

 After learning about the physics of flight, the students split up into small groups to design and build their airplanes using balsa wood and/or foam. First, each group brainstormed about what they wanted their airplane to look like and if they had any ideas for special features. Max, Gideon, and Zach decided that they wanted their airplane to be able to drop bombs, so they called their team “the Bombers”. This presented a design challenge because not only would “bombs” add weight to the plane but the team would need to figure what to use as bombs and design a mechanism to drop them.

After some discussions and a few sketches, the Bombers settled on a primary design: a balsa wood truss frame because it is an easy design for a strong and light structure. The first frame the team built ended up being too big so they had to make a smaller one. By the time the team finished making the frame for the plane David had assigned a new challenge: whoever creates the airfoil that can lift the most weight wins.

 The Bombers got right to work on the new challenge and Max created an airfoil that lifted 5.3 grams. The team ended up using Max’s airfoil for the wings. They did the calculations and decided that the wings would have to be one foot by six feet in order to lift the 200 grams that they predicted would be how much the plane would weigh. First, the team made the wings and attached them to the body. Second, the team laser-cut and attached the vertical and horizontal stabilizers. The reason that they had to make vertical and horizontal stabilizers was that without them one cannot steer. Also when the plane reaches its pitching point if it does not have horizontal stabilizers it would flip over. The vertical stabilizer balances out the plane and it also allows one to steer the plane to the left or right. 

The team used servo motors to allow the user to control the flaps. They also put flaps on the main wings so that the person controlling the plane can make it lean side to side. The next step was to make the box that holds the bombs. The team made the  bomb box out of paper and glued it to another servo so that when the servo changes angles the box tips over and releases the bombs which were made from party poppers. The final step was to attach the motor and propeller to provide forward force to the plane. In the end, the team went to an open field to test the plane and it flew well.