Project Development

Template for Project Development Entry

Our team Chemical Device:

So, our team came up with the idea to make an automatic tea maker that is able to make the perfect cup of tea. Our tea-maker will be able to adjust accordingly to the type of tea used like chinese tea, green tea, earl grey etc. This is to ensure that the tea is made at it’s optimum temperature and steeping time.
Chemical device sketch:
  
Team Planning, allocation, and execution

Team members:
CEO - Miguel
COO - Jun Weng
CFO - Brayden

Planned Timeline:

Actual Timeline:

Task	Date (Time)
Brainstorming	1/1 - 4/2 (36 days)
Material Collection	18/1 - 4/2 (18 days)
Coding	20/1 - 13/2 (25 days)
Physical Creation & Integration	2/2 - 16/2 (14 days)

Task Allocation:

Task	Person In Charge
Brainstorming	ALL
Material Collection	Jun Weng & Brayden
Design & Laser-Cutting of Housing	Jun Weng
Coding of Components	Miguel
Design & 3D Printing of small parts	Brayden
Assembly & Integration	ALL

Design and Build Process
In this section, provide documentation of the design and build process.

Part 1. Design and Build of Housing (done by Jun Weng).

Casing design plan: 

Assemble 6 different panels made from acrylic into a box.

Case design for the tea-maker:

Assemble the 6 pieces of acrylic into a cuboid measuring (25cm x 18cm x 10cm)
Slots implemented into each piece in order to improve sturdiness 

The front and side pieces are sandwiched in between the top and base pieces to provide more stability 

3D design:

Animation of the box assembly:

Assembly of casing:

After all the pieces are attached to one another, they are secured with hot glue                        along the inner edges. 

Part 2. Design and Build of gear & rack (done by Brayden).
https://cp5070-2021-2b02-group2-brayden.blogspot.com/ 

Part 3. Design and Build of supports (done by Jun Weng).

The support is made by cutting out a part of the original cuboid. The gap in the support was made to be able to contain the linear rack so it is around 1mm bigger than the rack.

Part 4. Programming of Motor, LCD & Temperature Sensor (done by Miguel). 
https://cp5070-2021-2b02-group2-miguel.blogspot.com/ 

Part 5. Integration of all parts and electronics (done by all members)

Embedded the finalized fusion 360 design file:

Documentation for integration:

Once all materials were ready, we put the housing together first. With the slots, it was easy to secure. We then added the cubes onto the corners, and then finally secured the slots with hot glue. The hinge for the door was put together with adhesive tape.
Next, we put the components inside. We set up the breadboard externally first, with connections to the components done later. We put the breadboard in the centre of the base, and components at their respective holes laser cut previously.
The Arduino board was then placed on the side so that there is less tension between the wiring of the components and the breadboard. The Arduino board would be powered by a power bank.

Once the wiring was complete, we put the support onto the rack and attach the rack’s teeth to the gear’s teeth. After testing there was too much force on the rack that it cannot move. Hence solid scraps had to be used to keep their shape and 

allow for movement.

Finally, as the rack could not fit the weight of the sensor, we placed it on the side of the housing. Here is our finalised design:

3D Printing

Problem:
- It was difficult to visualise and come up with the dimensions of the teeth for the linear rack. 
- The rack overall took a long time to print and make as there was a lot of experimentation with the parameters to make the final print. 

Solution:
- Make a small sample prototype to experiment and see if the design will work
- Make the final design smaller and thinner

Programming

Problem:
- The temperature sensor was not working on one arduino board
- Temperature sensor had started overheating despite correct arrangement
- No data came out

Solution:

- After a bit of counselling and tryouts we found that the issue stems from the Arduino board and not the sensor itself
- Use only one Arduino board for our prototype

Integration

Problem:
- The supports had too tight a gap to be used for intended use
- Original idea was to secure the rack using just 1 support
- After testing, there was little to no linear movement with just 1 small support

Solution:
- As one support is too small, we had to use different sized supports (scrap from our testing) to clamp the rack
- Able to enforce a very smooth linear movement while reusing material
The linear rack is also not inserted in the support as planned

Design Flaws

Problem:
- Stepper motor too weak
- Original idea was to use 1 stepper motor and attach the temperature sensor and strainer onto the linear rack
- Motor was unable to lift the linear rack more than once

Solution:
- Removing the temperature sensor and strainer from the linear rack to put less
stress on the stepper motor
- Replace the current stepper motor with a 12V stepper motor for more power

Grp hero shot with the prototype:

Project Design Files as downloadable files
https://drive.google.com/drive/folders/1yoQbMRRodQMxF3rG