Project Development

Project Development Blog Entry

In this page, I will:

1.     Briefly describe my team chemical device

2.     Show how the team planned, allocated the tasks, and executed the project.

3.     Document the entire design and build process of the chemical device and include videos, pictures, and screen captures of the processes.

4.     Include “Hero shot” of every milestone of the processes, example the part A that was 3D printed, part B that was laser-cut, electronics components moved/worked according to the program. Hero-shot is taken with the person-in-charge holding/working/making the parts.

5.     Include the name of the person who was in-charge of every part of the project.

6.     Document my individual contribution to this project.

7.     Provide the link to the page of the blog of my teammates.

8.     Describe problems encountered and how the team solved them.

9.     Include all the project design files as downloadable files.

10. Embed the final prototype design file, i.e., the final fusion360 design file showing the entire prototype.

11. Type my Learning reflection on the overall project development.

 

1.   Our team Chemical Device

A brief introduction on our team chemical device:

Our team chemical device is a door handle steriliser. Its function is to sterilise the door handle using UV light right after someone has just grabbed the door handle to open the door. In this case, since UV light is dangerous to use in our prototype, we will replace it with LED light strip. The body of our device will start at the bottom (resting position) and once the sensor detects the hand once someone touches the door handle. After 1 second the LEDs will light up and the stepper motor will rotate the body 180 degrees to the top and then back to the resting position.

So what problem will our chemical device solve:

Even after the pandemic, covid19 is still rampant and we do not want it to spread in social and crowded places such as offices, hence this is where our product comes in hand as most social interactions usually start off with a handshake and skin contact is the main contributor to the spread of diseases and viruses. Our device will sterilise the door handle with UV light each time after being used, which prevents any transmission of diseases and viruses.

Images of the sketches :

2.   Team Planning, allocation, and execution

CEO (Chief executive officer): Hai Teng

CFO (chief financial officer): Isabella 

COO (Chief Operating Officer): Ryan

CSO (Chief safety officer): Fion

COR (Chief of Resources): Wayne

Click here to view the finalized BOM (BILL OF MATERIALS) table.

Click here to view the finalized Gantt chart (planned and actual) and the task allocation for each team member.

Gantt Chart for CPDD Project: Design of a Chemical Device Door Handle Sterilizer	Version number: 1			Created by: Hai Teng
Team members:
1. Wayne (W)	Last modified on: 18/2/23			Checked by: Fion
2. Isabella (I)
3. Hai Teng (HT)
4. Ryan (R)
5. Fion (F)
Task	Done by	13/1/23	20/1/23	27/1/23	3/2/23	10/2/23	17/2/23
CAD drawing for outer case of the door handle steriliser	HT, R
Coding for the servo to move	I
CAD drawing for Door Handle, gears and rack	I
3D Print Door Handle, gears and rack	F
CAD drawing the Clamp, Clamp screw, Thread Connector and Thread Nut	HT, I
3D print the Clamp, Clamp screw, Thread Connector and Thread Nut	HT, R
Design Equipment box to hide all the wires and arduino	F
Laser cut the equipment box	F
Design the "caution" sign for laser cutting	F
Laser cutting for the "caution" sign	F
3D print the outer case of the door handle steriliser	R
Gathering all the materials needed to create the door handle steriliser	W
Gather all the different parts of the door handle steriliser together	W
Assemble the different parts of the door handle steriliser together	ALL
Check functionality of the door handle steriliser	ALL
Make necessary changes	ALL
PLANNED
ACTUAL

3.   Design and Build Process

In this section, I will provide documentation of the design and build process.

Part 1. Design and Build of Main Body (done by Hai Teng and Ryan). Link it to Spiderman’s blog

https://ryanseow06.wixsite.com/cp5065-intro-to-chem/project-developement

https://cp5070-2022-2b03-group4-haiteng.blogspot.com/p/project-development.html

Part 2. Design and Build of Wooden box, Caution Sign (done by Fion)

• Documentation for Task 1.

Wooden box:

The purpose of the wooden box is hide the Arduino, Breadboard and Wires that are visible. For the box, we used 5mm plywood and also created a joinery (box joint jig) to connect all the different sides of the box together. The allowance for the joinery is 0.2mm.

Sketches of the Wooden box

Design process of the Wooden Box on Fusion 360:

We will design 6 sides of the wooden box in total

For the Front side:

Step 1: Click “create sketch” → Select a plane

Step 2:  Click “2 Point Rectangle” on the top panel → Next, Indicate the dimensions (80mm x 170mm). *Can refer to the sketch*

Step 3: Select “construction linetype” on the right panel. → Locate the pointer on the top right-hand corner and mark the distance as “20.2mm” *Refer to the sketch for dimensions* → Click enter to confirm.

Step 4: Repeat step 3 but change the distance to “11.8mm” followed by “12.2mm”, “11.8mm” and “12.2mm”

Step 5: Repeat Step 3 and 4 for the left side of the Rectangle.

Step 6: From the top left-hand corner, mark “7mm” distance down from the top. *Make sure the line is still a construction line*

Step 7: From the endpoint of the “7mm” mark, draw a “160mm” construction line across the rectangle box.

Step 8: From the “160mm” endpoint, draw a “5.5mm” construction line down → click “enter”

Step 9: From the top right-hand corner, draw a 5mm construction line towards the left.

Step 10: Repeat step 8 for the top left-hand corner

Step 11: From the end point of the 5mm construction line that was drawn, draw one 20.2mm solid line (un-click the construction line) down the rectangular box.

Step 12: From the endpoint of the 20.2mm solid line, draw a 5mm solid line towards the right.

Step 13: From the end point of the “11.8mm” mark, draw a 5mm horizontal solid line towards the left

Step 14: From the endpoint of the 5mm horizontal line that was drawn in step 11, draw a vertical 12.2mm solid line down.

Step 15: From the endpoint of the 12.2mm vertical line that was drawn, draw another 5mm horizontal line towards the right.

Step 16: Repeat step 13, 14, and 15.

Step 17: For the left-hand side, draw a solid 155mm horizontal line from the endpoint of the 7mm construction line that was drawn in step 7. 

Step 18: From the endpoint of the 155mm solid line that was drawn, draw a vertical 5.5mm solid line down. → continuing from the 5.5mm vertical line, draw another 155mm solid line back to the left side of the rectangular box.

Step 19: From the endpoint of the 5mm construction line that was drawn, draw one 20.2mm solid line (un-click the construction line) down the rectangular box.

Step 20: From the endpoint of the 20.2mm solid line, draw a 5mm solid line towards the left

Step 21: From the endpoint of the “11.8mm” mark, draw a 5mm horizontal solid line towards the right

Step 22: From the endpoint of the 5mm horizontal line that was drawn in step 19, draw a vertical 12.2mm solid line down.

Step 23: From the endpoint of the 12.2mm vertical line that was drawn, draw another 5mm horizontal line towards the left.

Step 24: Repeat steps 21, 22, and 23→ Click “Finish Sketch”

And yes we are done with the sketch of the front side. Next, we will need to extrude the part that we want. 

Step 25: Click on “extrude” on the top panel → Select the middle part

Step 26: Indicate “5mm” as the distance that wants to be extruded. (This is the thickness of the plywood). → Click “ok”

Now, we are done with the front side of the wooden box✌. Here is what it should look like:

For the rest of the sides, I will demonstrate the steps in videos since the method of creating the other sides of the wooden box is more or less likely the same.

Click HERE to view the videos

Here is the embedded view for the wooden box.

Caution Sign:

In order to sanitize the handle, we will be using "UV light" to sanitize it, so the purpose of this caution sign is to attach it to the body of the door handle sterilizer to remind users to be aware of this light so they are not affected.

The caution sign was designed using Corel Draw, which allows me to include different shapes easily for the design.

Sketch of the caution sign:

Design process of the caution sign on Corel Draw: 

Step 1: Click on the "Square icon" on the left panel

Step 2: Click and drag on any point on the A4 paper → Set the dimension of the rectangle to 140mm x 20.4mm on the top panel

Step 3: Click on the "polygon" shape icon on the left panel

Step 4: Click and drag to any size → Change the number of sides to “3” on the top panel, beside the polygon shape icon.

Step 5: Click on the “A” icon on the left-hand side panel to insert text → Type “!” → Double click on the text to move them around

Step 6: Repeat Step 5 but change the text to "CAUTION"

Step 7: Repeat Steps 3 to 6 for another 2 more times

The final look of the caution sign

You can view the video below on how to sketch the caution sign on Corel Draw:

To assemble the box, we drill 2 hole on the back side so that we can hang it on the fake “door” that we laser cut just like a photo frame.

• Hero Shot for Wooden box

To prepare to laser cut, set the "CAUTION" word and icon to engrave and laser cut the rectangular box.

This is what the Caution Sign looks like after laser cutting.

Part 3. Design and Build of Clamp, Clamp Screw, Thread Connector and Thread Nut (done by Hai Teng). Link it to blog:

https://cp5070-2022-2b03-group4-haiteng.blogspot.com/p/project-development.html

Part 4. Design and Build of Gears and rack, Arm (done by Isabella). Link it to blog:

https://cp5070-2022-2b03-group4-isabella.blogspot.com/2023/02/project-development.html

Part 5. Design and Build of Door Handle (done by Fion).

Door Handle Sketches:

Design process of the door handle:

Step 1: Click “create sketch” → Select a plane

Step 2: Select “centre Diameter circle” on the top panel

Step 3: From the center point, draw a diameter of 40mm → followed by another circle of 18mm diameter from the center point

Step 4: Click “finish sketch”

Step 5: Click “extrude” on the top panel and select the outer layer of the circle to extrude. → Extrude 10mm distance.

Step 6: Hide the bodies and show the sketches out. → Select the middle circle to extrude 80mm

Step 7: Click “create sketch” → select the tallest point of the 80mm long block that was extruded → Click “Create” → “slot” → “Center to Center Slot” 

Step 8: Position the cursor on the middle point of the circle, click and drag the cursor to a

distance of 135mm.

Step 9: Click "enter" and drag your cursor down and key in "18mm" distance. → Click "enter" →

"finish sketch"

Step 10: Select the sketch that was drawn → click "extrude" → Select the distance to be "-18mm"

Step 11: Click “create sketch” → Select the inner side of the body that was extruded

Step 12: Select “centre Diameter circle” on the top panel → position to your cursor to the center of the end point

Step 13: Click and drag the cursor to a 18mm diameter

Step 14: Click "finish sketch" → Select the sketch that you have draw → Click "extrude" on the top panel → key in "42mm" as distance to be extruded

Step 15: Select "fillet" on the top panel

Step 16: Select the whole body → Make sure the corner type is "rolling ball" → Specify "fillet radius" to be 1mm → Press "enter"

And we are done! Here is the final look of the door handle:

You can click here to watch the video on the process on how i made the door handle

Below is the embedded file of the door handle:

Part 6. Programming of motor and lcd (done by Isabella). Link it to blog:

https://cp5070-2022-2b03-group4-isabella.blogspot.com/2023/02/project-development.html

Part 7. Integration of all parts and electronics (done by Everyone). NO LINK

• Embed the finalised fusion 360 design files
• Documentation for integration
• Hero shot for integration

Assembling the box and gear together:

What we did was just to combine the different sides together by super glue the 5 sides together to form a box (exclude the lid).

Next, paste the rack under the lid and drill holes on the front so the gear could be attached to the box.

To assemble the box, we drill 2 hole on the back side so that we can hang it on the fake “door” that we laser cut just like a photo frame.

We used screws and nuts to secure the gears the box.

Here's the video of how the gear turns the lid in:

Hero shot of all the parts that I did was attached on the fake door:

Assembling of wires into the main body:

Firstly, we ran all the wires that are needed into the mainbody :

Next, we combine 2 parts of the main body and slide the caution sign onto the body to secure them together.

After that, we attach the tread connector in the hole made in the orange main body and attach the arm and nut to hold the arm in place

We then connect the arm to the servo:

Lastly, we attach the stepper motor into the clamp box and clamp it on the door handle:

Here's the embedded file of our final door handle steriliser:

Click the link below to Watch how our prototype work:

https://www.youtube.com/watch?v=typysZxmSpI

Hero shot with our final prototype 👻:

4.   Problems and solutions

For 3D printing, the filament used for the body of our device broke halfway through the print, which caused the print to be incomplete. We found out from the lecturer that the filament we used was faulty, hence for the subsequent 3D prints we used a different printer and made sure the filament used was not faulty.

We initially wanted to print the body of our device in one whole, when the print came out we realised that we were not able to install all the components and hide the wires well and the print that came out was incomplete with some loose ends to the design. To resolve this issue, we printed the body into two halves so that way we will be able to hide the wires easily and all the components would be easy to install.

During the laser cutting process we messed up the dimensions of our box, as it was too small to fit the breadboard and all the other components. The box was initially designed in a square box and we realised its too small to fit both breadboard and arduino. Hence we've changed the design to a bigger rectangular box so that we can fit both arduino and breadboard in. The caution sign was too thin so the fit was not very good as it was super loose. We changed the allowance so that the caution sign is able to fit perfectly. The caution sign was printed total 4 times in order to get the correct fit so that we could slide it into the body of the prototype without dropping out.

For the Arduino portion one of the main drawbacks was that the LED light strip was 12V, however the Arduino only carries a maximum of 5V. In order to make up for this we attached the LED to a 12V battery. Next would be the coding of the LED light, instead of creating a new code for it we instead attached it to the same circuit the red LED would be in. This is due to how we initially designed it, where when the red LED turns on, the LED strip will start sterilising. This allowed us to kill two birds with one stone.

5.   Project Design Files as downloadable files

In this section, I will provide all the design files (Fusion360 files, .dxf files, .stl files, arduino programs files) as downloadable files.

• Fusion files: https://drive.google.com/drive/folders/1NjCaGLmaRZJfAz_PVdtd8ADTyl1q9KDd?usp=share_link
• STL files: https://drive.google.com/drive/folders/1UWdlbepsevW3UF3lQ0nEmaX4owvW9aON?usp=share_link
• .dxf files: https://drive.google.com/drive/folders/1fUyFnqGe0kWqDM21b81F83DT9_0DLWmx?usp=share_link
• Aruino programming files: https://drive.google.com/drive/u/1/folders/1y0Xlx4osMxzrOtmaxfR5VzhVu_7ABeHR

6.   Below is my Learning Reflection on the overall Project Development.

For this project, we are to create a door-handle steriliser that requires all the skills that we have learned in ICPD and CPDD. Initially, I didn't have much faith in ourselves like how are we supposed to design it. We flip through lots of resources online and eventually came up with the design that we have now.

During the designing stage, it got me a little bit difficult to imagine how a small little stepper motor is able to turn the 3d printed body up and done. But slowly when we get into discussions and making the prototype, I could finally understand how the stepper motor work. It took me quite a while.

In the process of prototyping, I learned to push past my limits and never give up, despite multiple failures during the project; I kept a positive mindset and found a way to overcome all obstacles.

Since I am in charge of making the wooden box and caution sign, I've done lots of trial and error on both the wooden box and caution sign. It wasn't hard to design the product out on fusion. It was the dimensions that we keep on getting wrongly so end up I have to redesign it again and again to get the correct size. One problem that I have with the wooden box is changing the dimensions. The caution sign is easy to change the dimensions because I only need to resize the length and breadth of the caution sign to make it fit into the slot on the main body. However, the biggest problem is the wooden box. As mentioned in the previous section in the "problems and solutions" I designed the box into a square shape instead of a rectangular shape. This made me redesign everything on fusion and also my hand sketch drawings. I've tried scaling the square box into a bigger square box but still, it couldn't fit both the breadboard and Arduino and my allowance given to the joinery on the box will be scaled up too. So no choice I have to redesign the square box into a rectangular box and it is very time-consuming.

I've also remembered that our plan did not include making the door handle and fake door. But after discussing with one of my teammates, we realised that we should 3d print a door handle and laser cut a fake "door" to better demonstrate our chemical product. It wasn't a bad idea eventually.

One thing our group should have done is to draw out a proper sketch of the main body device with all the dimensions on it and also make a proper cardboard prototype with the exact dimensions of our real device as this would have allowed us to not face as many problems as we did. There are a few times that our print was in the wrong dimensions and extra components were designed unnecessarily. This is obviously due to the lack of proper planning and sketching. However, it got better towards the end although it was pretty rush for us to finish the prototype in time. We took these as our learning opportunities and it is also part of a trial and error in giving the correct allowance to give to our dimensions.

Overall, I really enjoyed building the Door Handle Steriliser as I was able to bond with my teammates although the process was super tough and tiring due to the heavy workload that we have from other modules, we still got to juggle all our work with this at the same time. All in all, it was still a pretty satisfying feeling after seeing our prototype work. I'll never regret doing this although it was super tiring.