week 3&4 First RespondAir

nuot@uci.edu 2017-2018 VTOL First Responder

Hello everyone, the past two weeks our team was busying with the design analysis, manufacturing methods, and the development of the tilting mechanism. From what I have mentioned in last blog, our team has sized the lifting fan and chose the motor attachment. After sizing the lifting fan, we started with the center of gravity calculation for both cruise and vertical flight. For the cruise part, we calculate the center of gravity to meet the stability requirement. The center of gravity must be located in front of the neutral point of the airplane. For the vertical flight, we designed the hinge location for wing for moment arm to control pitching moment with lifting fan.

Our manufacturing team was on the page of deciding the manufacturing materials: whether to use balsa wood or foam for the wing. Balsa wood has a light weight but none of us has experience with it. Because we have some experience with fiberglass layup, we decided to go with foam wing. However, there is a limitation on foam thickness: only 2 inches thickness available. Therefore, we had to reduce airfoil thickness and change the airfoil selection to have enough lift. To do that, we did trade studies for additional thrust required in hovering due to camber airfoil.

We also made a decision for the fuselage and landing gear. Instead of manufacturing those, we decide to buy a kit which has the same dimensions of our design and modify the kit for the prototyping and educational propose. With the kit, we will keep the landing gears and fuselage part and make our own wing and integrate the lifting fan on it. Since our project is mainly focusing on tilt wing, by doing this we could learn about the wing structure and fuselage structure and spend more time on tilt wing mechanism.

We are currently working on the tilting mechanism. We compared between gear box and two servos scenarios. Gear box is heavy and expensive, which would not be our best choice. For the two servos scenario, we need to make sure that these two servos must be in sync and have to produce enough torque, which is also need some more studies and research.