Week 12 Mechanical Design, Machine Design

This week's assignment is about Embedded Networking and Communications. I am using an Arduino UNO to create an RFID Door Lock System.It’s a fun and secure way to unlock the door.

Learning Objectives

👥 Group Assignment

• Design a machine that includes mechanism + actuation + automation + application
• Build the mechanical parts and operate it manually
• Actuate and automate your machine
• Document the group project

👤 Individual Assignment

• Document your individual contribution

Learning highlights

Lucky Wheel Selector / Topic Spinner

💡1 Mechanical Brainstorming

I had a two-hour creative session with my instructor Nancy and ChatGPT, during which we exchanged ideas and explored possibilities. As a result, we arrived at our final mechanical design plan.

🎡2 Lucky Wheel Selector / Topic Spinner

✨ Function Overview

This is a mechanical structure with a rotating wheel, driven by a stepper motor. Wherever the wheel stops, it selects a student, a question, a group task, etc. It can be used for:

• Random question selection
• Group assignments
• Classroom games or prizes
• Choosing duty students

📦 Function Overview

No.	Item	Quantity	Specification / Description
2	Stepper Motor	2	Used to rotate the wheel & Horizontally Moving Finger Mechanism
2	Stepper Motor Driver (A4988)	1	Controls the motor via Arduino
3	Arduino UNO Board	1	Main controller of the system
4	Connectors (3D Printed)	1	Attach the finger model to the sliding rail
5	Gear Wheel (2D Laser Cut)	2	Spinning wheel for random selection
6	Timing Belt (optional)	1	Use of Sliding Rails
7	Power Supply(12V|1A) / USB Cable	1	Provides power to motor and Arduino
8	Push Button	1	Starts the wheel spinning
9	Screws / Nuts / Connectors	Varies	To secure and assemble components
10	Color Labels / Sticker Paper	Varies	For writing names or tasks

3 Control Unit

Control Unit, responsible for receiving, processing, and sending instructions. Key components: Arduino Uno board, expansion board, 4 corresponding chips, 3 female-to-female jumper wires, and a 12V power supply.

Reference Article

For detailed documentation and pin reference
Arduino CNC Shield Reference

Tutorial Video

Watch the tutorial:
Arduino CNC Shield Tutorial

4 Computer Aided Design (CAD)

2D Gears & Laser Cutting

In this section, 2D gear designs were created using GIMP. The designs were exported as SVG files and prepared for laser cutting using 3mm thick basswood.

3D Connectors & 3D Printing

Custom 3D connectors were designed to assemble the gear system components. These parts were modeled in 3D CAD software and printed using a 3D printer(Creality ). The connectors ensure structural stability and precise alignment of the moving parts.

5 Machine Assembly

01 Assemble the gears

02 Install the X-axis motor

03 Connect the finger model using connectors

6 Machine Testing and Operation

This week's testing is complete. Next, I will work on the V2 version of the device.

To be continued.

2D design for this week 3D design for this week