Making with Cardboard: Free and Forgiving

John Bordoni
  

John Bordoni

October 6, 2015

As a maker, I know that being faced with a large project can feel intimidating. The journey from idea to final physical form always contains questions and unexpected problems that need to be resolved before reaching the final goal. Careful planning and CAD modeling both help the process, but it is often difficult to know if something will really work until it can be seen in physical form.

That’s why I am a firm believer in making with cardboard.

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Prototyping for the masses

In the early stages of prototyping, I’ve grown to love tackling problems with basic materials on hand. While the final product will be made out of a sturdier materials such as wood, plastic, or metal, they’re tough to work with and time consuming to form. You don’t want to be halfway into the build, realize that a key feature of your project isn’t going to work, and have to restart—especially if the final materials are expensive or rare. This is where cardboard has proven helpful in my creation process. The benefits of working with cardboard are numerous – it’s plentiful, cheap, and easy to shape and cut. I really saw the power of such a simple material first-hand in my projects as a Kinoma Maker in Residence this summer.

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Cardboard as a learning process

One of the first projects I worked on at Kinoma was the Tank Control chair. When envisioning the project’s ideal form factor, the other Makers-in-Residence and I wanted to experience different modes of controlling the tank that were physical. At those early stages, we didn’t know that the controls would take the form factor of a chair. We started out considering slide potentiometers and rotary potentiometers, and we wanted to find out what each form factor might require.

Using two inexpensive, plastic rotary potentiometers, a cardboard box, and a glue gun stick, the beginnings of the eventual tank chair took shape. Cutting up a small box, I made two quick “handles,” each made out of two rectangles of cardboard that were then glued together. I pulled the plastic knob off each potentiometer, found that the leftover shaft press-fit nicely into the middle of a small servo hub, and used that increased surface area to glue onto our makeshift cardboard paddles. Just like that, in under ten minutes, we had a working prototype.

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One of the nicest things about a simple physical model in cardboard is that it is very easy to pull unexpected observations when testing a particular prototype. For example, we found that the handles would need to be much longer to have the desired effect, and that we would need much sturdier potentiometers. These observations helped us move forward with the project.

Making a Skeeball Gumball Machine with cardboard

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Cardboard was used even more in the Skeeball Gumball Machine project. An initial challenge was determining exactly how gumballs would be dispensed into the playing field. We knew acrylic would make up the majority of the final project, but that material was too expensive to use in testing out the gumball dispensing mechanics.

Originally, the idea was that gumballs would be stored underneath the playing field, and would rotate one at a time into play with the help of a servo and a 3D-printed wheel. This seemed doable at first, but I wanted to be sure. Using just cardboard and a glue gun, I created multiple “dispensers” to test out. I first tested a zigzag pattern that lined all the gumballs into a single file and filtered them into the rotating wheel. But I learned that the zigzag pattern would need to be precise in order to avoid jams. After that, I removed the zigzag pattern and attempted to dispense the gumballs without a single file line. I also tried rotating the wheel 90 degrees. Neither worked.

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While these failures were disheartening, they led to observations that ended up paying off. The angle of the gumball reservoir was too shallow, and gravity was not enough to ensure a gumball would be selected. This led to another prototype that used gravity to our advantage, and it ended up working fine. We used cardboard again to figure out the ramp angle and angle of the playing field. Because cardboard is so easy to bend, it was pivotal in answering each of these questions, and led to observations that informed the final product. I’ll be posting more about this project soon, so stay tuned.

3D Printing and Making with Cardboard: A love story

While 3D printing a prototype is not as fast as making a prototype out of cardboard, it is better for more precise parts. This is especially true for parts with geometries that are hard to make with cardboard, such as circles or cylinders. 3D printed mockups can typically be sketched in CAD software, then printed in just hours (depending on size and complexity). This is faster, safer, easier, and more precise than using wood or metal. 3D printed parts are also versatile, as they can be used in the prototyping process and the final product.

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3D printing played a role in rapid prototyping the Skeeball Gumball Machine at the beginning of the design process, and as part of the final product. Numerous iterations of the dispensing mechanism of the gumball machine were tested with 3D printed parts paired with cardboard. We also used 3D printed parts to test out numerous iterations of the bracket on the Tank Control chair. Small changes could be easily made, and since each part could be printed in under five hours. With 3D printing, we were able to develop the bracket much quicker than if we had used wood or metal, and much easier than perfecting the dimensions in cardboard.

Time efficient, cost effective

Each of these prototypes took less than 30 minutes to create, and best of all, were very inexpensive. Cardboard gives makers the huge advantage of insight into prototype dimensions, angles, and simple mechanical designs. Despite this, it isn’t perfect for certain prototyping projects. Smaller, precise parts are often more easily made with 3D printers. I have found that the combination of using quickly designed and manufactured 3D-printed parts along with cardboard can lead to even more insights than cardboard alone. And while strong enough for many projects, weight bearing projects should be prototyped with a more sturdy material, such as wood.

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Saving time and money is professional

I used to think that cardboard prototypes looked silly and unprofessional. I felt that using such a cheap material couldn’t possibly be helpful, and that you only really know what will happen until you use the final material. While there is a grain of truth to that last statement, experimenting with cardboard knocks out a majority of unanticipated problems. Questions about sizes, shapes, and angles don’t need to be solved with the exact material, since most any semi-sturdy material will do – and the properties of cardboard make it a worthy substitute.

It took me a few years to realize that my fear about professionalism was misguided. Anyone you present a prototype to will understand the power of cardboard, especially when the final project benefits from such a time and cost-effective approach that enables rapid iteration and leads to a better final product.

John is a Mechanical Engineering and Computer Science student at Stanford University with a background in content creation, manufacturing, and graphic design.