Welcome back to one of the best blog sites in SP DCHE. Before I get started on anything, this blog will be my last one. However, don't fret or worry as I plan on upgrading this site to include my past projects and events I've participated in in the past rather than just focusing on one module. In today's blog, I'll be covering the entire design and development of a CO Detection System my teammates and I have been working on for the past few months.
Describe My Team's Chemical Device
What are we making?
Why are we making it?
Research
Team Planning, Allocation, and Execution
Planning Stage
Role Allocation
Project Execution
Morphological Chart
Concept Sketches
Concept Evaluation Matrix
Triz
Revised Concept
BOM
Gannt chart
design and build processes
Cardboard Prototyping
Arduino Coding
Cardboard prototype working video
Fusion 360
3D-Printing
Laser Cutting
Assembling Final Prototype
Final prototype working video
Describe problems encountered and how the team solved them.
Wires getting tangled
Fusion format for laser cutting
3D printing errors which led to components not fitting
Acrylic glueing
Project design files as downloadable files.
Learning reflection
1. Describing My Team's Chemical Device
a. What are we making?
A Carbon Monoxide Detection system
b. Why are we making it?
c. Research
2. Team Planning, Allocation, and Execution
a. Planning stage
Before we started to think about what types of materials and mechanisms our CO Detection System needed, we focused on the performance requirements of the system and the user needs to address. We concluded this in the figure below:
Figure 1: Performance and user empathy requirements
We then created an overall function structure diagram of a CO Detection System to understand how many inputs and outs our system will eventually have and this is shown in the figure below:
Figure 2: Overall function structure diagram of CO detection system
Not long after, we created a more detailed and complex diagram of the CO Detection System as shown in the figure below:
Figure 3: Detailed function structure diagram of CO detection system
b. Role Allocation
c. Project Execution
3. Design and Build Process
Cardboard Prototyping [My Individual Contribution]
Initially, we weren't even meant to create a cardboard prototype in the first place. However, on 1st February, when I was meant to go to the lab to start 3D printing some of our components, all the 3D printers were already occupied by 8.15 am.
So instead of playing around and wasting time in the workshop, I grabbed a piece of cardboard and started visualising how our prototype will look like when we use the acrylic sheet. This was also very helpful because now I was able to physically visualise the exact dimensions our acrylic sheets need to be during laser cutting.
I used Figure 14 which we drew during class to first understand the basic dimensions of our prototype. I then referred back to the dimensions of the acrylic sheet we had which was 800mm by 420mm. I also referred back to Figure 15 which Jian Lun helped draw for us to roughly know how many pieces I should be cutting and where they will end up when hot glueing the cardboard pieces together.
Figure 15: Prototype piece allocation
Here are a few pictures my friends took of me while I was cutting and assembling the cardboard. I don't really have that many since this wasn't a planned activity we had:
Figure 16: Scrap parts Figure 17: Cardboard prototype after glueing
I then measured the size of the components that need to protrude out of our bottom ceiling which were the LED, motor and MQ2 gas sensor using a digital vernier calliper.
Figure 18: Dimensions of holes required in the bottom ceiling
This is what the cardboard prototype looks like after cutting out all the holes:
Figure 19: Cardboard prototype after a few weeks
Arduino Coding [Diana]
Cardboard Working Prototype [Group]
Once Diana completed the code in the lab, we immediately assembled the prototype and the video below shows it in working conditions.
Fusion 360 [My Individual Contribution]
This is going to be a long one, so I'll just state the individual steps I took to create a fusion file for our Rack & Pinion, Door and vent.
Rack & Pinion + Door:
1. Click on Modify and select "Change Parameters"
2. Insert the following parameters for future purposes
3. Click on the Utilities Tab
4. Click on ADD-INNS, then select Scripts and Add-ins
5. Select "SpurGear"
6. Insert the gear parameters as mentioned in step 2
7. Click "OK"
8. Add construction lines down the sketch
9. Draw a borderline for the teeth on the rack
10. Offset the rack teeth to create a shape like this
11. Insert another sketch of a rectangular segment to a length of your liking
12. Duplicate the teeth across the entire length of the rectangular segment.
13. Extrude the Rack to be the same width as the Gear.
14: Create a sketch on the gear to make a rod stick out of the gear
15. Extrude by 10mm
16. Fillet the sides of the door to create a smooth surface
Vent
1. Create a circular sketch of 62mm in diamter and offset it by 2mm
2. Extrude the sketch by 150mm
3. Create a hole of 10mm which is 30mm above the base of the cylinder
4. Sketch another circle with a diameter of 7mm in the middle of all the other sketches
5. Extrude it by 3mm to create a base with a small hole in the middle
3D Printing [My Individual Contribution]
Laser Cutting [Jianye]
Integration of All Parts [Jian Lun]
Final Working Prototype Video [Group]
Hero Shots
4. Problems & Solutions
Problem 1: Wires getting tangled up during the final assembling stage
We required a large number of wires to connect the breadboard to various components, such as the LED and motor, and during the final assembly, these wires often got tangled. To overcome this challenge, we had to rearrange the positioning of the breadboard and Arduino kit to create more space, allowing us to separate each component more effectively.
Problem 2: Fusion format for laser cutting
3D printing errors which led to components not fitting
Acrylic glue took a longer time to dry than expected
5. Project Design Files as Downloadable Files
6. Learning Reflection
In the beginning, I think that this final project has encompassed all the skills that we learned from ICPD and CPDD. We applied the core skills that we acquired, including digital modelling with Fusion 360, 3D printing, laser cutting with a laser cutting machine, and using gears for mechanisms, making this a very long and tedious yet rewarding challenge.
This project also taught me the value of teamwork, as it allowed us to complete the task efficiently. We divided the workload evenly, leveraging each other's strengths. For instance, Jian Lun and Diana are proficient in programming and Arduino, so they handled the coding aspect. Jianye and I concentrated on 3D printing and laser cutting, as well as integrating acrylic sheets with acrylic glue. This enabled us to execute our plan seamlessly because we all worked in our comfort zone.
As the adage goes, "every man is a piece of the continent, a part of the main." We brainstormed together to generate more ideas, and due to limited access to the acrylic sheet, we had to reduce our prototype's size and make essential adjustments to our dimensions. Hence, we reduced the number of fans and Arduino kits in our prototype but we were still able to meet the objective of the system.
This journey taught me several valuable troubleshooting skills that I can apply in the future. During 3D printing, I discovered that one of the EnderCreality printers was printing out black-coloured filament which looked burnt. I tried my best to clean the nozzle head, but in the process, I discovered that the rubber coating on the nozzle head had actually melted and I informed Ms Serene immediately. I also learnt how to conduct maintenance on Ultimaker S3 when it isn't extruding any filament from the print nozzle.
Overall, I feel fortunate to have collaborated with my amazing teammates on this project for several weeks. I somewhat enjoyed the process and hope to implement the skills I've gained into my capstone project in year 3.
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