Project Development
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
- In
this section, I will briefly describe my team chemical device.
Our chemical product is a door handle
sterilizer. The chemical device will sterilize the door handle after someone
has used it. First, when the person touches the door handle to open it, the
sensor at the back of the main body will detect the hand. After releasing the
handle, there will be a 1 second delay before the ‘UV light’ lights up and the
stepper motor rotates turning the main body 180 degrees around the door handle to sterilize it and turning back to its
resting position at the bottom.- What
it is. What problems will the chemical device solve?
During
the pandemic, we have realised how COVID-19 has affected our lives. To minimise
the spread of the virus, we have to clean and sterilize frequently touched
surfaces such as door handles. As it can survive on surfaces that are frequently
touched for up to 28 days at around 20oC, which makes the survivability
of the virus in offices much higher than any other place. Therefore, we have
come up with this chemical device to be use in offices which can sterilize and
clean the door handle each time after use to prevent the spread of the virus. - Below
is the hand sketch of the chemical device.
2. Team Planning, allocation, and execution
Team roles:
CEO (Chief excutive officer): Hai Teng
CFO (Chief financial officer): Isabella
COO (Chief operating officer): Ryan
CSO (Chief sales offcer): Fion
COR (Chief of resources): Wayne
Finalised BOM table:
Finalised Gantt chart and the task allocations:
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 using 3D printer (done by Hai Teng and Ryan)
Step 1: Sketch a 60mm diameter circle and a line cutting through the middle
Step 2: Extrude a semi circle of 70mm
Step 3: Sketch a rectangle to put the sensor (Since this is half the body, sketch half of the sensor length and breadth (16.5mm X 8mm))
Step 4: Extrude 5mm inwards
Step 5: Sketch a 40mm circle
Step 6: Extrude 70mm
Step 7: Sketch a 40mm X 5mm rectangle
Step 7: Extrude 70mm downwards to form the base where the LED strip will be
Step 9: Extrude 10mm downwards
Step 11: Extrude 10 mm to create the pegs
Step 12: Create a 20mm X 3mm rectangle to put the caution sign
Step 13: Extrude 140 mm to create a space for the sign
Step 14: Sketch a 6mm circle to put the LED
Step 16: Sketch a rectangle to cover the semi circle on the top and extrude it 10mm inwards (This was a mistake as we wanted the wire to come out of the other side)
Embed file of Main body 1:
For Main body 2, repeat the same step and switch the sensor and LED position and extrude inwards to make holes for the pegs with 0.2mm allowance. On the other side of the body, make 3 holes with diameter of 15mm for the middle to hole the connector and 12mm for the side for wires to come out.
Embed file for Main Body 2:
To print, export the drawing as an STL file and upload onto cura. Select the correct printer and desired infill. After that, slice and save to the SD card and insert onto the printer and start printing.
Cura:
Printed Version:
Hero shot:
If I have the chance to redesign the body, I would make sure that the dimensions of the sensor is correct as when we are attaching the sensor, it was protruding out from the sides which indicate that it was not the correct dimension. I would also give a 0.2mm allowance instead of 1mm for the LED hole as the hole for the LED was too big. Another change is to make the hole for the wiring closer to the center as when the print came out the hole was 70% blocked by the inner wall.
Part 2. Design
and Build of Wooden box, Caution Sign, Arm using laser cutting (done by Fion
and Isabella)
Part 3. Design
and Build of Clamp, Clamp Screw, Thread Connector and Thread Nut Using 3D
printer (done by Hai Teng).
Clamp:
Step 1: Sketch a 'C' like shape with the dimensions and fillet the corners
Step 2: Extrude the sketch by 20mm
Step 3: Sketch a 8mm diameter circle on the top for the clamp screw
Step 4: Extrude a hole
Step 5: Thread the inner part of the hole by going create > thread > select the face for thread
Step 6: Sketch a 40mm x 47.5mm in the middle of the clamp
Step 7: Extrude out by 29mm
Step 9: Extrude 19mm inwards
Step 10: Sketch a rectangle for the wires connecting to the stepper motor
Step 11: Extrude the sketch
Cura:
Printed Version:
Clamp Screw:
Step 1: Sketch a 20mm diameter circle
Step 2: Extrude the sketch by 20mm
Step 3: Sketch a 10mm diameter circle on top of the cylinder
Step 4: Extrude by 3mm (This will be the base for the threads)
Step 5: Sketch a 7.8mm diameter circle on top of the smaller cylinder
Step 6: Extrude by 25mm
Step 7: Thread the cylinder by clicking the dropdown on create > thread > and selecting the surface to thread. Make sure to select model or else the thread will not be printed.
Step 8: Offset the bottom and top of the threads by -0.1mm (This is to give some allowance so that the thread can be screw in easily)
Step 9: Select the edge and fillet by 0.05mm (This is to give rounding to the edge of the threads to allow is to last longer)
Step 11: Extrude by 5mm
Step 12: Add a sphere on top by clicking on the dropdown of create > sphere > and selecting the surface on the top of the cylinder. Make a 10mm sphere and under the operation select join.
Cura:
Printed Version:
Video of the print in action:
Thread Connector and Thread Nut:
Step 1: Sketch a 14.97mm diameter circle
Step 2: Extrude by 30mm
Step 3: Thread half of cylinder by going to the dropdown of create > Thread > selecting the surface of the cylinder. Untick full length and drag the arrow down till it is half way there. Tick modeled and OK
Step 4: Select the top and bottom of the thread and offset by -0.1mm by clicking the modify dropdown > offset face
Step 5: Select the edge of the thread and fillet is by 0.05 by clicking the modify dropdown > fillet
Step 6: Click on the file (The red arrow) and select new component for the nut
Step 7: Sketch a circumscribed polygon with a diameter of 13mm and a circle with 14.97mm diameter in the middle
Step 8: Extrude downwards by 10mm
Step 9: Click the inner hole and thread it using the thread function
Cura:
Embed file:
Thread connector:
Thread Nut:
Video of the print in action:
Hero shot:
Part 4: Design and Build of Gears, Rack and Arm (done by Isabella)
Part 5: Design and Build of Door Handle (done by Fion)
Part 6: Programming of Motor and Icd (done by Isabella)
Part 7: Integration of all parts and electronics (done by Everyone)
Finalized Design:
Integration:
First, we run the wires for the LED and sensor into the holes in the main body.
Attach the thread connector in the hole made in the orange main body and attach the arm and nut to hole the arm in place.
Attach the other end of the arm into the stepper motor
Assemble the box together and gear together
.jpeg)
.jpeg)
.jpeg)
Hang the assembled box onto the door
Connect all the wires onto the Arduino and breadboard
Final product:
Product in action:
Hero shot:
.jpeg)
4. Problems and Solutions
Problem 1: Initially we decided to print our main body in one shot, however, we realised that it would be impossible to put in the electronic components inside the body and the body would take too long to print.
Solution 1: We decided to split the main body into 2 which allows the electronic components to be put in easily and the print would take 3 hours with a good print quality instead of 3 hours with a bad print quality.
Problem 2: When we laser cut the box caution sign, we did not account of the dimensions of the electronic component that we will be putting in and for the caution sign we expect it to slide into the main body easily but it was too loose.
Solution 2: For the box, we made it 2 times bigger and instead of using 2 3mm ply wood pieces, we used just 1 5mm plywood to make the box which would be able to hold all of the component. For the caution sign, we measure the gap in the main body and cut the sign which took about 4 tries before we manage to get it fitted perfectly.
Problem 3: The threaded component that I printed out initially cannot be screwed on because I did not give it any allowance.
Solution 3: By watching youtube video on how to give it an allowance, I was able to get the threaded components to work when they are done printing.
Problem 4: For the LED strip that we used, it is 12V but the Arduino only has 5V. Recoding of the LED strip.
Solution 4: In order to make up for this we attached the LED to a 12V battery. 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
6. Below is my learning reflection on the overall project development
When we were first told that we have to make a chemical device which would be able to work, I thought is would be rather simple to make. But I was very wrong after going through this project. In this project, we have to utilise all the skills covered in CP5065 and CP5070 such as CADD, 3D printing, Laser cutting, Arduino Programming and integrating a mechanism design such as gears and cams. It was difficult to integrate all of this skills we have learn into a chemical device as this is the first time that we are making it.
Since we choose to make a door handle sterilizer, we started with using systematic design framework to identify the main problems and specific requirements for the door handle sterilizer. After brainstorming for several ideas with the requirements, we came up with 5 solutions. We prototype each design and discuss among ourselves to see which solution would work best and eventually settled on one.
During the pre-prototyping phase, we met up as a group as it was difficult to give ideas and suggestions online. We listed down all the task that needed to be done and split the workload among ourselves.
During the prototyping phase, I realised how communication among groupmates is very important due to many different components done by different people. For example, since I am in charge of making the hole for the caution sign which is being laser cut, I would have to tell my groupmate about the dimensions and have to pass her the main body in order for the caution sign to fit perfectly onto it.
Before getting the correct dimensions for everything, we went through many failed attempts such as the threads not working like how it was suppose to be. Instead of giving up, I did some online research on how to make it work and eventually it did work which I was really proud of. It is important not to keep dwelling on those failed attempts as it would have made me gave up doing the project. Eventually, we were able to get every component to work perfectly with each other.
Overall, this project was a very enriching and enjoyable one as I have been able to put what I have learn in class to the test and then some. Before this project, my fusion skills was not bad but during this project, I feel like I have improve my skills and learn how use different tools in fusion such as making threads and making the exploded view for my team.
Comments
Post a Comment