Overview
ME 30: Electronics and Controls I
Tufts University, Fall 2023
This solo project was constrained by two factors: The game needs to utilize a motor and must require user input. This project was completed over the course of a week and a half and was my first electro-mechanical project. My personal goal for this project was to create an aesthetically-clean project that hid major electronic components.
Tufts University, Fall 2023
This solo project was constrained by two factors: The game needs to utilize a motor and must require user input. This project was completed over the course of a week and a half and was my first electro-mechanical project. My personal goal for this project was to create an aesthetically-clean project that hid major electronic components.
Design Process
In order to promote seamless design integration, I focused my early efforts on thoroughly planning the mechanical and electronic design before touching any building materials. I drew inspiration from one of my favorite childhood arcade games and chose to create a small version of arcade ball drop.
My design sketches are shown to the right. When I was thinking through the dimensions of my game, I started by designing the game around the size of a ping pong ball. From here, I was able to design the circular game board and gauge how large the walls of the game should be and identify the best place to house the electronics. |
Your browser does not support viewing this document. Click here to download the document.
|
Integration
Mechanical integration:
After creating sketches of the mechanical components, I used Onshape to create laser cutting files for the circular game board as well as the game box. The ball-holder was made of a PCV pipe which I cut to length with a vertical bandsaw and drilled holes into. The laser cut components were straightforward to design and put together - my main integration challenge was installing a clear wall around the game board. I decided to create the game walls out of flexible plastic, and was able to procure several pieces of smaller plastic that had to be joined together. To the right you can see the multiple ways I attempted to connect pieces of test plastic. After trying to use a heat gun to melt the plastic together, using packing tape and punching holes in the plastic with a nail then securing with bolts, I decided that the bolts created the strongest and aesthetically cleanest connection. In order to secure the plastic in the back, I created tabs so that the plastic could be bent 90 degrees and secured. I used a shoelace-like string structure to hold the plastic together to prevent extra strain on the bolt connections. |
Electronics Integration:
I started by prototyping the electronics before I fit them into the mechanical design. I used a N-channel Mosfet to control a DC motor with a Adafruit KB2040 microcontroller. The goal of using the KB2040 with the DC motor was to reduce the speed of rotation using pulse width modulation. While experimenting, I learned that the minimum duty cycle for the motor to run was around 23000 out of 65000. Next, I wired the button so that the KB2040 read input from button presses. Lastly, I wired my servo motor and began writing code. This was my first time using a servo motor with Python, and I quickly realized that Circuit Python has a servo library. Once the electronic components were working as desired, I placed the pieces with the rest of the mechanical system. The breadboard was housed underneath the game board. |
Adjustments and Final Product
As I integrated my design, multiple changes were made. I initially intended to use a stepper motor to release the ball, but later switched my design to utilize a servo motor when I realized I had access to servo motors. Given the time constraints and my goal, I decided to remove the speed control component from the game in order to meet the deadline. In order to prevent balls from being stuck in the back two corners, I secured two strips of plastic to fill the empty space.
Images of the final game are shown below.
Images of the final game are shown below.
Reflections
I believe I achieved my goal of creating an aesthetically-clean game while working in the design constraints of the assignment. I learned about designing electro-mechanical systems while continuing my personal journey to build cleaner designs. One major takeaway from this project is the value of researching previous implementations of similar designs. By utilize resources posted online, I was able to find more efficient ways to implement my designs and challenged my initial thought process.