My next assignment in HCDE 451 marked my first interaction with 3D Printing. Throughout my time at UW, I have always seen other peers design and develop their own creations with 3D printing, so I hoped to come out of this project with a brand-new skill.

For this project, we had the creative freedom to print any object we wanted, in which I aimed to design a water bottle car cup holder using the following operations:

• Extrusion
• Revolution
• Boolean (adding or subtracting one object from another)

Design

As always, I started the creation of this design in my sketchbook, where I drew versions of what I imagined this cup holder should look like. Once I narrowed down several sketches into a final design, I created another sketch with specifications for the design, including the length, height, and depth of the cups. Drawing this final design from different perspectives also gave me an idea of how I would model this in Rhino.

Sketches and specifications of my final water bottle car cup holder prototype

When it came to modeling in Rhino, I went through different methods of creating the cup holder until I came with a few that helped shape my final design.

• Extrusion - To create the base of the cup, I extruded the bottom curve into a surface.
• Boolean Intersection - The upper cup and cup base were overlapping, but I wanted to make sure only the cup base acted as the “filled” part of the design. Intersecting worked better than Boolean Union, which could not identify the intersection in the first place.
• Revolution - I kept getting errors in trying to create a circle hole in my upper cup, so I revolved a curve and used Boolean Subtraction to “unfill” the upper area.

Screenshot of the Rhino file I created to print my cup.

Prototyping

Because this was a very large prototype, I created smaller-scale versions of the cup holder to test its durability and make sure that the model was printed correctly. The two small-scale cup holders can be seen below, in which my first print is in blue filament and my second in yellow.

Prototype 1 (blue) on left and prototype 2 (yellow) on right

Top view of both prototypes

Rough edges from printing errors and removing supports

I took these two cup holders to HCDE 451 for critique and feedback to improve upon for my final iteration. I asked for specific feedback on the marksmanship, durability, and usability of my cup holder. One thing to note is that because I did not have time to print the large-scale cup holder yet, I did not test whether my personal water bottle had fit into the cup holder, but rather tested how effective the smaller-scale prototypes could hold similarly shaped objects. Below is the feedback I received from these prototypes:

• Marksmanship - Prototype 1 (blue) looks a bit rough, as if the supports weren’t taken off carefully. Prototype 2 (yellow) felt smoother and visually looked like a cleaner print.
• Durability - Both prototypes felt very sturdy due to the filled bottom section. Both individuals giving feedback found that the smaller bottom also made it great for stacking, which meant putting the cup holders away would be easy and efficient.
• Usability - While this project is intended to be printed on a larger scale for my water bottle, it is still successful in holding other similarly-shaped objects, such as lip balms or lipsticks. Even so, the height of the cup does not securely hold everything due to its medium depth. The only instance in which this cup holder would successfully work well would be in carrying an object that is very close in diameter to fill the entire cup.