Prototypes: Designing Your Ideas

Prototyping for Fun and Profit

“You should prototype it.” I said.

I was sitting in my friends’ living room and they were telling me about the new island they were planning for their kitchen. Will thought a larger island would provide a nicer eating surface. Mona countered that a larger surface might jut out too far into the walking path. Both good points, but how do you know where the right compromise lies?

“Why don’t you get a big piece of cardboard and mock up the top of the island?” I suggested. “You can slide it in and out to see how different sizes feel in the space and how much room you actually need. You could also test a few different shapes to see how curved you want the edge.”

I create prototypes for everything.  Well, just about.

At Lever Gear HQ, the walls in our office are cardboard panels. They won’t always be, but the cardboard is a cheap way to break up the space and live in it for a while to see how it feels and how functional it is. If we discover we need more room for our fulfillment area for example, no problem, we just move the wall.

When I set out to make the perfect batch of homemade iced tea, I designed prototypes in several small batches playing with the ratios of green and black tea; sugar, stevia and honey; lemon and other flavors until I found a recipe that is delicious and nutritious.

As a designer, both through training and practice, I’ve learned the immense value of prototyping. When I was consulting, I would include the sentence, “I like to prototype early and often,” when describing my process in a design proposal. I wanted to reinforce the idea that we’ll spend a little bit of time and money on prototyping early in the process to avoid spending a lot of time and money later down the road.

Why Prototype?

It’s a creative design tool. Just like sketching, designing a prototype is a great way to get your ideas from your brain into the world. It’s a way to record and communicate your ideas and build off those ideas.

It provides information and feedback you didn’t even know you needed until you see it in real life. I can’t tell you how many times I’ve designed something on the computer and then created a prototype and realized, “Wow, that’s a lot bigger (or smaller) than I thought.” Or maybe a part fit’s in the design but when you prototype it you realize it’s difficult to assemble. Even with simple products, there are so many factors in play, it’s impossible (or inefficient) to think of every implication of the design until you actually build it.

Work out the bugs. Every time you iterate and prototype, you discover little issues and fix or improve them. Ideally, you can reduce the number of iterations needed to finalize the design.

Testing your design. How does it perform in the real world? How does it feel? You can’t really know until you build it. Let’s say you’ve designed a snap-on cap that you’ve calculated requires three pounds of force to remove. What does that mean to a human? Three pounds is nothing if you are doing squats but what if you a pinching a small object with your fingers? Will three pounds be enough to prevent accidental opening? Let’s test it.

Prevent costly mistakes that waste time and money. Yes, prototypes cost money and/or they take time to build. But that’s nothing compared to the time and money it could take to fix a problem after you’ve gone to production. Prototyping is the designers’ version of “measure twice, cut once.”

End up with better products. The reasons above add up to one result—a better product. Your final product will be more innovative, work better, be more robust and less expensive if you take the time to create prototypes, test, and evaluate your designs along the way.

Different Types of Prototypes

There are many different types of prototypes that serve different purposes. Sometimes those types can overlap or serve multiple functions. Below are the five main types of prototypes for physical products as I see them.

Mock-ups. These are quick and dirty. Mock-ups are analogous to thumbnail sketches where you are simply exploring ideas. They can be cardboard, string, tape, hacked up products, or anything that can quickly and effectively get the idea across.

Form models. These show you the size, shape and sometimes general color breaks of an object. They’re particularly useful for handheld object to see how they feel. They are more detailed than mock-ups and often made of foam, foam core, clay, wood, plastic or any sculptable or 3D printable material.

Appearance models. These look like the final product. The materials and finishes should look real in photographs or in person. Because they’re realistic, you can use these prototypes in marketing materials. They can also help designers choose between color options, finishes, etc.

Engineering prototypes. The purpose of designing prototypes is to test the mechanical or other engineering functionality of a product. They are made from as close to the final material and process as possible. They can be the whole product or just a small part or mechanism. These prototypes can be used for compliance and safety testing to validate the design before production.

Fit, Form, Function prototypes. These combine aspects of form models, appearance models, and creating prototypes. They are comprised of the individual parts of an assembly and can be used to determine how well the parts fit together, how they are assembled, and how the final product will look and function. These prototypes don’t have to look true-to-life like appearance models, but they often do. They don’t require all parts to be made with their actual material and process like designing prototypes, but they can. Typically, these are CNC machined parts or 3D prints.

Prototyping Case Study: Designing the CLiP™ System

Each of the prototype types above played an integral part in the design of our latest products—The BitVault™ and BitLight™.

In the early stages of the design, I created several quick mockups to get a general idea of the size and shape of the products and test the idea of having a slide out drawer. These were a mix of foam, paper, and even some other small products that I cannibalized to approximate our product. Later in the project, I used some simple mockups to test out some ideas I had for how to create dividers for the inside cavity of the BitVault™ to organize bits and other small items.

As the industrial design concepts became a bit more refined, I used more carefully crafted foam form study models to get a good feel for the shape and feel of the different concepts. How did the products look? How did they fit on a keychain or in your hand? Was the shape too boring? Too complicated? Did it look too much like similar sized existing products? These form models helped answer those questions and led us to the chamfered octagonal bar form that is the basis for the CLiP™ System.

As we refined the mechanical design of the CLiP™ System, we went through a few iterations of fit, form, and function (FFF) prototypes. These were mostly plastic, 3D printed rapid prototypes of the individual parts. Using these we were able to assemble together to test the functionality of the parts and assemblies. We made the rubber parts like the o-ring gasket, BitLight™ button, and LED gaskets by pouring silicone into a rubber mold created from 3D printed parts. It’s an extra step that takes a bit more time and money but creates true-to-life parts. Some parts—like the spring steel release clips—had to be made from the actual metal due to the thin size. Having parts from the actual metal also allowed us to test how the clips would function. Low volume, sheet metal prototypes are fairly expensive but sometimes you need to use the real material.

These prototypes were critical in figuring out key aspects of the design. For example, our first round of FFF prototypes had a shell design that had an internal draft, which would be needed if we were to diecast the shell part. After assembling and testing the parts, we discovered that the initial drawer sliding function of the Bitvault™ didn’t work very well because the fit became too sloppy as it slid out. We learned valuable information about how the o-ring sealed, how the release clips worked, where parts needed to be beefed up or slimmed down, etc. With each iteration, the design improved until it was ready for prime time.

As we were creating our Kickstarter campaign, several of these FFF prototypes were turned into appearance models to take pictures for our campaign that would show what the final products would look like. Pressed for time (and cash-flow), the models didn’t turn out as well as I would have liked. In a perfect world, we would have had a prototype shop create professional appearance models for us using real materials and finishes. Instead, we had to settle for me pulling an all-nighter to sand, prime, and paint the plastic models before hopping on an 8 am flight that morning. I think our Kickstarter campaign suffered as a result of not having great appearance models to work with. Lesson learned.

Finally, before we finalized parts for production, we created several sets of FFF engineering prototypes made from the actual materials and similar processes to what the final parts would be. Prototyping metal parts can get very expensive. But it was essential to have working models as close as possible to the final product to perform engineering tests and make sure there weren’t any hidden issues. Also, we needed to have the BitLight™ tested and certified by a third party to comply with certain safety regulations. To make the testing valid, our prototype parts and assemblies had to be essentially the same as the final parts.

Conclusion

Prototyping is an essential part of the product design and development process. Investing a small amount of time and money on prototypes up front can give you a ton of feedback. And prototypes can actually speed up the design process by keeping you from going down dead-end roads. The price of 3D printing has come down substantially over the past decade and the list of available materials is large and growing. I actually got some nylon printed parts made for a few bucks. Amazing! You can even 3D print metal although it’s still rather expensive. If you’re a small business, the only thing to watch out for is that the costs can add up—especially for metal parts or appearance models. Make sure you’ve proven the concept to the point where it’s ready to invest in metal parts when needed. Other than that, go for it! Prototype early and often.