THE MAKERS: Sean Riley's The Ergo Kiwi Knife

Sean Riley is a student at the Boston Architectural College in Boston, Massachusetts. Here he talks about his design innovation, the Ergo Kiwi knife. Our interview tracks his process from ideation to completion. The Ergo Kiwi Knife is now available! Go and get yours today!

Describe your product.

The Ergo Kiwi is an innovation on the traditional pen knife. It’s designed to reduce stress, strain, and to promote prolonged productivity.

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What inspired you to create your product?

I originally created the tool for myself so that I could work for longer periods of time making models for design studio without cramping up. 

Tell us about your design process. 

I made my first model out of sculpting foam but couldn’t use it to create a working prototype, so I had to duplicate the handle out of wood.

Once I had a form that I was satisfied with I created a template so I could cut as many blanks as I needed. Then, I would sculpt them with a Dremel and sand them with a belt sander.

After making a few iterations I had students at the Boston Architectural College beta test them. I’d analyze the way they held the handles and made adjustments based on my observations. Every person has a different size hand and holds the handle differently, so I made sure to account for that in the prototype.





After about a year of research and development I finally had a handle that I was satisfied with.

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At this point, it was time to make some 3D printed models. I had to teach myself the 3D scanning software (NextEngine 3D scanner) as well Rhinoceros (3D modeling software) so I could modify the 3D mesh that the scan created. After that process, which took about two months, I was able to 3D print prototypes to send out to architecture firms to be tested some more.


After testing the handle in a few model shops at Boston architecture firms, the only complaint I received was that the blade would get stuck in thicker materials. So I added a latch which utilizes the prefabricated hole in the blade to lock the blade in place.




[The blank being milled. I used Baltic Burch plywood with 1/64 inch (0.4 millimeter) layers to show the contours of the handle. The stepover on this finishing pass, which is like the resolution, is set to .005 inches (0.1 millimeters) so in the end you have a clean precise handle. Each handles takes about an hour and half to mill and another 30-50 minutes of finish work.]

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How did you decide which tools to use?

The choice of tools changed from traditional to modern fabrication techniques as the project progressed. In the very beginning I used a lot of hand tools to create physical models out of foam and wood because I didn’t know any 3D modeling software. After I had a physical object, I needed a 3D model, so I had to teach myself to use a 3D scanner and Rhino to modify the 3D model. Once I had that, I was able to print prototypes. 

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Share a resource that helped you in this project.

Where do you typically display your work online?

Instagram, Facebook, Twitter, Personal Website,

Tell us about your school’s architecture program.

The Boston Architectural College is an accredited architecture school located in the Back Bay area. The program is designed so that students work during the day at a design related firm and attend classes at night.

What do you intend to do upon graduation?

I’ve already started a business based around the product that I’ve created which I will be running. After graduation I plan on using my design education, fabrication skills and entrepreneurial experience to start a fabrication firm which takes ideas from concept to physical product to manufacturing. As well as pursue other business opportunities from additional products that I’ve patented.


If you want more information about the ErgoKiwi knife, please visit their website:

Check out the Kickstarter campaign!

Also, read on at ArchDaily, “How I Developed Ergo Kiwi, an Ergonomic Craft Knife that Your Fingers Will Thank You For.”

Here are some beautiful images of the finished product. Prepare to drool!

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