HCDE 451: Model-Making

Anna Schmitz
Oct 15, 2019 · 5 min read

Within University of Washington’s Human Centered Design and Engineering program, students have the opportunity to take HCDE 313, where they learn various methods of prototyping in UX. The class is held within UW’s CoMotion Makerspace, a university-available space dedicated to helping young inventors and entrepreneurs express and create their ideas. HCDE 313 in particular focuses on physical prototyping, through various mediums for a wide variety of purposes.

In the first assignment of the class, students were asked to review three case-study-like prompts, then pick one to ideate around using model-making. These three cases were: a handheld electric screwdriver, a shower control interface, or a pet-grooming appliance. All three held one common requirement: they must utilize the principles of “universal design”, as exhibited by OXO in their accessible and ergonomic kitchen products.

I chose to ideate around an electric screwdriver. This topic contained several real-world constraints:

  • Variable speed control
  • Head selection mechanism
  • Direction selection mechanism
  • Digital readout for items screwed/unscrewed
  • Usable right- or left-handed
  • At least 6 inches long
  • Contains a rechargeable battery
  • Weighs between 1–1.5 lbs

After conducting competitive analysis, I noted that several models contain a plethora of control mechanisms in an illogically-laid fashion, suggesting that users of these tools are experts or power users, and rely on the flexibility of the tool they choose. However, few matched OXO’s theme of ergonomic and universal design. I drew inspiration from the Dremel Go V4 Max Screwdriver, the closest model I analyzed to holding the features listed above.

Dremel Go V4 Max Screwdriver

Thus, I noted what was successful in the case of the Dremel: it was convenient, durable, intuitive, lightweight, and compact. However, I noted there were opportunities for improvement, in particular around the rigid ergonomics and odd layout of switches and sliders. Thus, I started with a sketch of a model with the same basic cylindrical shape as the Dremel, and began sketching rapidly.

Sketches of possible ergonomic electric screwdriver models

My focus with these sketches was to remain loyal to the principles of OXO, focusing first with the ergonomic grip. I understood that in order for the screwdriver to be usable and functional, it must first be hold-able in a comfortable and efficient way for many types of users. Many of these sketches include organic-like sculptural features or unique padding to convey that idea through form. Afterwards, I experimented with adding accessible interfaces, following how I might expect a user to interact with each grip type. In order to understand this better in a real-world context, I transitioned from sketching to modeling.

First physical iteration of an ergonomic screwdriver model

The base of this model came from a hand-turn screwdriver, which I wrapped in plastic wrap and covered in modeling clay. The center grip is made from cotton string. This model, I realized is almost perfectly weighted at its most narrow point on the grip, and in the neighborhood of 1–1.5 lbs. The base hand-turn screwdriver provides some context — what the screwdriver bit’s rigidity means in terms of expectations for future models of this prototype. It demonstrates immediately what this should be used for, while allowing me to iterate over its form quickly with basic materials.

For the constraints on controls, I had simple ideas for how to incorporate them: the screwdriver’s power is fueled by internal batteries that can be accessed through a hinge at the bottom of its body. The screwdriver turns on with a large power button located where the user’s thumb would rest. Beneath it is an “eject” button, meant to switch out the screwdriver head easily and quickly. The center grip serves three functions: direction, speed, and control. Twisting the grip to the left makes the screwdriver spin counter-clockwise. The further the user spins it left, the screwdriver accelerates in that direction. Likewise if the user turned it to the right. The digital display is located at the bottom of the screwdriver.

Screwdriver prototype at an in-class critique

Later on, I reviewed this prototype with my peers and professors in the HCDE 313 classroom. We visited one another’s work in a science-fair-style critique session, where each student was able to ask questions directly to the creator or leave comments on sticky notes.

Results of critique session in HCDE 313

I walked away with plenty of thoughtful considerations. Firstly, many enjoyed the minimal interface I gave the user, with an intuitive layout of buttons customized to OXO’s ergonomic focus. However, many realized that the center “rotating control” grip isn’t practical. A user cannot twist the grip single-handedly — therefore, it’s necessary for at least part of the grip to be stable while a smaller part of the grip would rotate.

Many commented on the fact that the weight was comfortable and realistic. It wasn’t, however, an accessible size for everyone. People with larger hands had difficulty holding it appropriately. In the future, I’d create a more robust model at at least a 2X scale from this iteration.

A last frequent remark was at how similar this design is to the aesthetic and appeal of OXO’s brand. It seemed like something their designers would theorize, in order to maintain their stance on universal design and a comfortable ergonomic experience.

In conclusion, I’m happy with the results of this exercise. I walked away with plenty of sketching experience and a fresh opportunity to bring one particular design to life. Once I held this design in my hand, I felt I could understand it far better, in relation to its use case and target user. I found myself thinking in far more “blue-sky” terms than hard engineering terms, something that I am learning to control in my HCDE projects. Although we are an engineering discipline, we treasure the opportunities to think quickly and abstractly about what’s possible. I’ll carry forward the importance of physical modeling in product design and how it demonstrates design in action.

Anna Schmitz

Written by

Human-Centered Design + Engineering at University of Washington. A relentless creator, musician, and reinvisioner of a better world.

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