2018 Winter Semester Flying Robot Project Team B Article 1November 28, 2018


We decided to make a twin-boom model airplane with a pusher configuration. A pusher configuration is one of the structures of airplanes, and propellers are mounted behind their engines. Therefore, the fuselage is pushed by propellers, rather than pulled (this type is a tractor configuration). The reason we chose a pusher one was that we wanted to avoid the propeller’s crushing in flying accident. We have not get used to manipulating airplanes yet, so it was very likely for our plane to collide with walls in a flying test. If the propeller were attached in front of the body, it might be damaged and break down. In addition, our plane is a twin-boom, so it has a horizontal stabilizer across its two vertical stabilizers, so it has two rudders.
In this week, we designed ribs of the main wing, vertical stabilizers, a horizontal stabilizer and a fuselage with CAD (Computer Aided Design, Fusion 360). The ribs were based on 6400 of 4-digit NACA airfoil series and the stabilizers were composed of square bars with 2 mm square. Afterwards, we cut balsa wood plate with laser cutter as shown in the design drawing of the ribs. On the other hand, we printed the drawings of the stabilizers, cut balsa wood square bars and assembled them with instant adhesives and hardeners while arranging the bars on the drawings. The assembly was easy, but we needed to suppress the bars’ distortion as much as possible. Finally, we attached rudders and an elevator on stabilizers with hard tapes after we glued CFRP (Carbon Fiber Reinforced Plastics) bars in front of the stabilizers in order to strengthen them. The figure shows the frame of the stabilizers, but they have not been fixed to one another.
In the next week, we are going to make the main wing. The span will be about as long as 1.4 m, so we have to cooperate and work efficiently.

Takashi Koyama
今週私たちは主翼のリブと垂直尾翼、水平尾翼、胴体の設計をCAD(Fusion 360)を用いて行いました。翼型はNACA4字系の6400を参考にし、尾翼は2 mmの角棒によって構成されています。その後、レーザーカッターを用いて設計図の通りにバルサ板からリブを切り出しました。尾翼については、図面を印刷してからバルサの角棒を切り、図面に載せながら瞬間接着剤と硬化剤を用いて組み立てました。組み立ては簡単でしたが、棒の歪みをできるだけ抑える必要がありました。最後に、強度を上げるためにCFRPの棒を尾翼の前に接着してからラダーやエレベーターを硬いテープで貼りつけました。図ではまだ固定はされていませんが尾翼の骨格が示されています。
次週私たちは主翼を作る予定です。翼幅は約1.4 mにもなるので協力して作業を効率的に進める必要があります。

小山 高