The Goal

The assignment in Stanford's course titled Computer-Aided Product Realization was as follows:

"this assignment is to design a bottle opener starting from the thought exercise of 'in the mind of a squirrel...' Think broadly."

A key component of this course was its emphasis on lateral thinking and quality ideation.

Initial Brainstorming

After sketching many pages of work related to nutcrackers, acorns, and abstract monsters,

I settled on eyes as a primary launch point for my future investigation, leaning into the jittery motion of squirrels and how a similar motion occurs in the human eye.

Additionally eyes are often the window to emotion and I wanted to leverage this to create a deranged creature in the form of a bottle opener.

Existing Research

In order to create a functional bottle opener, I looked into currently existing 3D printed and aluminum bottle opener solutions to draw inspiration and make note of key dimensions and design elements as I began to iterate on my initial sketches.

Bottle opener dimensions helped to inform key sizing elements such as how large to make the cap interface

Existing 3D printed bottle opener which illustrated features and dimensions to mitigate risks of weaker bottle opener material

Prototype Sketch

After learning more information on CNC work-holdings and best CAM practices,

I refined my current design to allow for the use of soft jaws.

This required making a flat bottom on the design as seen below.

Prototype sketch featuring soft jaw design and rough mouth dimensioning

Early CAD Modeling

To further refine this design for manufacturing with the 3-axis Haas CNC machine available to me, I had to reduce the undercuts occurring at the eyes to reduce the part flips required to manufacture this device. After making these changes and taking into account previous research,

I printed the model to validate its sizing and usability as a bottle opener using a Formlabs resin printer using the material Rigid 10k.

Updated CAD model featuring the removal of undercuts near the eyes and mouth dimensioning informed by existing research

Formlabs 3D resin printed prototype fabricated using rigid 10k

Some key learnings from this prototype were that the product could in fact open a bottle, but that a smaller tongue tab was key for ease of usability.

Additionally the bottom curvature of the mouth needed to be flattened in order to provide more space to insert the bottle to increase usability in the product.

Taking these learnings from my first prototype, I refined my CAD model and used this updated model to begin creating CAM in order to manufacture the product on the Haas CNC machines. I was very intentional in the order of my set-ups so as to minimize error when flipping the part, in addition to simplifying the manufacturing process as much as possible. See the CAM previews for each setup below.

Set-up 1: Drilling the eyes and mouth

Set-up 2: Cutting the bottom face to fit in the soft jaws

Set-up 3: cutting the top body of La Ranita while holding the part using soft jaws

Additionally I ran FEA simulations to ensure that the updated geometry wouldn't experience excessive deformation when manufactured using aluminum.

FEA analysis using a 100N load on the tip of the tongue indicated very minimal deformation which indicated feasible use

Tool holder collision occurring on the final set up. I faced many issues like this due to the overall geometry of the bottle opener

One big issue that I faced throughout this project was the parts steep vertical height, causing tool collisions due to tool stick out limitations.

Most tool stick outs and flute lengths which cut the block of metal were not long enough and as a result there were many tool collisions in the software. As a result I made the overall structure of the design more conical, I roughed the overall shape using large tooling which had larger tool stick outs and flute lengths, in addition to sectioning off the design into finishing tool paths that properly cleared and finished the aluminum while avoiding tool collisions. Those finishing sections can be seen below.

Ramp finishing tool path, using 1/2'' ball end mill to leverage its longer length

3D contour tool path, using 1/8'' ball end mill, avoiding tool collisions with shallow depth

Scallop tool path, using 1/8'' ball end mill, avoiding tool collisions with shallow depth

Fabrication

After polishing the CAM and collaborating with our teaching team, I was ready to move into the Product Realization Lab where I would use the Haas-CNC machine to fabricate this bottle opener. The process required two part flips which were planned and thought through during the CAM and manufacturing brainstorm, and the process of manufacturing can be seen below.

1. Part after set-up 1 and 2 shown earlier

2. Part clamped in soft jaws just after photo left

3. Part after first pass adaptive roughing clear

4. Part after second adaptive clear using smaller tooling

5. Part after all finishing tool paths

After removing the part from the vise as seen above, I finished with brief sanding to 1500 grit in order to give the product a consistent and shiny finish. The final finish can be seen below.

La Ranita final product photograph

I poured so many hours into this project, but man was it worth it. Getting into the weeds with CAM and dealing with multiple part flips, soft jaws, new finishing strategies, and tool collisions taught me so much about CNC and design. Perhaps even more so

I learned, in action, the true iterative nature of the design process.

Working with long tool stick outs and a limited number of work-holding mechanisms forced me to reconsider my design geometry many times. There were many CAM sessions where I even considered abandoning the whole project due to its complexity, but with the help of the fantastic teaching team and some peers in the PRL, I am so proud to have realized this design as it is now. Leaving this project I feel so much more confident with my ability to follow the design process, work with and optimize CAM, handle part flips, soft jaws, and CNC set up and operation, and I can’t wait to take these skills into my future. I am so grateful to have had this amazing opportunity and look forward to future design projects and opportunities.