The design began with the reference AEV. It was used to get the team comfortable with basic coding as well as the set up of the basic components (Arduino, motors with propellors, AEV arm, battery). The Reference AEV was also used as a standard of comparison for each concept design. It was the beginning step of the team’s final design.
Dan’s design was decided to be the deign for the team through the concept screening and scoring matrices. The design has been built in Solidworks as shown in Figure 1 and it went through a series of different variations using different materials.
Figure 1: AEV in Solidworks
A prototype was built by Dan using a cardboard cereal box, which really helped the team visualize the Solidworks design in real life. The purpose of this project was to get a 3D model of his vision before creating the 3D ABS design and Balsa Wood Design.
During the Grant Vote, Division J was granted 75% funding because they won 2nd place so with the help of that money, the outer shell in Figure 1 will be produced with a 3D printer.
It was found that the 3D printed version of the design was very heavy and used sufficient energy, so Dan decided to build a model out of balsa wood. The model was hallowed out to reduce weight and energy, thus making it more efficient. Paint and decals were added in order to make the Space Shuttle Design come to life.
As far as the other design components, the braking and the propellers, Advanced Research and Development labs were conducted.
- During AR&D 1, a servo was added to the AEV as the main braking system. The servo was decided to be the best way to brake the vehicle due to its efficiency and speed in braking.
- AR&D2 helped show which propellor configuration would be best. It was decided the flat, rounded design would be implemented.
The design of the servo changed significantly throughout the process. It started with a cardboard top with duct tape and a metal bracket. It was found that as the servo was used more, the cardboard would get pushed down, thus, the braking distance would become farther due to the wear of the head. This design was inconsistent but it was a good start.
The team then made a new servo out of balsa wood with hot glue as the material on the tip to get a better a more consistent brake. The team had concerns, however, that the momentum of the stop would split the balsa wood. In order to problem solve, a third and final design was created combining the two previous.
Using the metal bracket from the first servo design and the balsa wood and hot glue head from the second servo design, final design was created. During testing, this servo had the most accuracy plus it was durable and reliable.
In addition, the coding has been a crucial part of this project. The different codes used throughout the process can be found here.
The evolution of the design in pictures is shown below:
1st Design: Reference AEV