Here is how the hardware was created:
1. After brainstorming and testing many different materials for the hull, I decided that this foam was the most customizable, lightest, and cheapest option.
2. I made a template for the size/shape of how I wanted the boat to be. I overlaid the template onto the foam, and cut it out in my school's tech lab.
3. After cutting it out, I sanded it at an angle to create a protruding "hull". Then, I traced a rectangle on top of it, and cut out an insert to place the electronics in.
4. Next, I looked up the dimensions of the mounting holes for the electronics I was using, and used a rough sketch to lay them out.
5. I used a small piece of plastic to mount the electronics to, and screwed them in.
6. I then laid the electronics board inside of the indent I created. This photo was before the electronics were actually mounted.
7. I used 3d printing to make several structural components that needed weird shapes. Learn more about my 3d process below.
8. After assembling, wiring, and screwing, I had my boat!
3d Design
This was one of my first experiences with 3d design/3d printing. I used a very beginner software called Tinkercad to familiarize myself with the 3d environment. While being very simple, it was also very effective and enabled me to do everything I wanted to do. Additionally, it is a cloud based software, so I could use it on any computer, at any time, and have all my designs with me. I used it for three main parts:
The Bridge
This was a bridge to mount my motors in the center of the robot. Since the sonar sensors in the front were only going to give me a distance to the object, I decided to use polar coordinates as my navigation system. Putting the motors in the center would allow me to move the robot evenly, instead of a traditional boat's motors moving the front hull slower than the back.
Motor Mount
In order to avoid complicated and often malfunctioning support structures while printing, I designed the motor mounts separately from the bridge. They screw in directly to the bridge, and keep the motors in place from the front. Additionally, this part can be used for more than just this project, as it is just a screw-in mount that holds the motor in place.
Sonar Sensor Mount
Early on in the design process, I realized I wanted three separate front-facing sonar sensors. I needed a way to mount them facing forwards. I was already using 3d printing for the bridge/motor mounts, so I saw that 3d printing would be a good solution to this problem as well. I used a micrometer to measure the radius of each circle, and the distance between them. Then I placed them next to each other in Tinkercad. Finally, I designed spikes onto the bottom to help it grab into the foam and stay put.
Phase 2 Hull
As we began to add more sensors, and possibly move into computer vision navigation, we realized we needed more room on board. So, we decided to move to a larger, more sturdy hull. For this, we retrofitted a toy boat hull with a flat surface for mounting electronics. More information on this is coming soon.