No product makes it to the marketplace without making several types of prototypes first.
It is a necessary process to validate both form and function of the product. In the same way that the needs of a child change as they get older, the goals and the style of prototyping evolve, too. In the early stages, several types of prototypes are made to test the core technical concepts to create the DNA of the product. Later stage prototypes test functional features and integration of the whole product, as well as aesthetic elements. Eskimos have 50 different words to describe snow, and the Edison Nation and Enventys teams have a language of their own to describe the different types of prototypes that we make during the course of a program. The following are the different types of prototypes that we make and how they help get a product to market.
Concept Model Prototypes
Concept models are early stage prototypes that test the core functionality of the product. It is where most of the discovery and new technology is developed and is one of my favorite phases of product development. Our tagline about concept models is that they are “too big, too heavy and too ugly”. However, they work, and most of the patentable features are based on learnings from these prototypes. Concept models are often Frankensteined together from parts harvested from existing products and easy to form materials. Plywood, PVC, empty soda bottles and other scrap materials are some of our favorites. The goal is to quickly combine the elements of the idea together to see if it is going to work without concern about aesthetics. We often do not make any computer models of the parts unless we need to cut a part on a laser or water jet cutter so that we do not get too time invested in CAD on a given design. We make as many concept models as necessary to answer as many questions as we can before proceeding with development.
Form models are used to test the aesthetics, size or touch points of a product. They are usually made in the early and middle stages of development if it is necessary to get a read on how the outer surfaces of a design before devoting time to working out the details of the interior features. This is especially important for products that have a need for good ergonomics like handheld devices.
Our favorite way to make form models is to print them on our powder based 3D printer, the 3D Systems Projet 660. It prints fast and the material is inexpensive. It can also print colors, which can be helpful for some prototypes. The prints are usually heavier than the final product, but it is useful to test how a product fits in your hand and get an early read on color choice. Alternatively, they can be made by carving high density foam to the desired shape which can save time at the CAD terminal.
Looks Like / Works Like Prototypes
As the product matures, the need arises to make looks like / works like (LLWL) prototypes. These are used to test the total package of the product in a form that is ready to manufacture. Like the name suggests, it has both the aesthetics of a final product and working internal components. They provide valuable data to the engineering team to catch design flaws before manufacturing. They can also be used for marketing in the form of focus groups or can be used to launch a crowdfunding campaign. Most products require at least two rounds of LLWL prototypes before transfer to manufacturing to work out all of the bugs.
A LLWL model cannot be created without a large outlay in hours by the engineering team. A fully detailed CAD model needs to be created with all of the components and circuit boards. This allows the design to be evaluated and tweaked in a virtual environment and is a great way to catch mistakes before making parts. Once the CAD files have been reviewed and approved, the parts are made the fastest and least costly method that uses a material that is as close to what will be used in manufacturing as possible. It is common to have 3D printed parts, however machined parts are used too. If there are electronics inside the product, a circuit board will be designed and fabricated by a quick turn PCB house and hand assembled in the lab.
The completed LLWL prototype is evaluated for function and assembly. It is the first chance where the performance of the product can be measured and compared to the desired performance metrics at the start of the project. The prototypes are tested in a representative environment to make sure they perform well. The prototype is also assessed for ease of assembly and part fitment. This can be tricky with 3D printed parts as they are built in layers and cannot always be built to a tight tolerance.
Once the prototype has been evaluated for the “works like” part of the equation, it is made to “look like” a final product. This usually means that it gets paint and decals. Painting can be a time consuming process, but the results are worth it. 3D printed parts have to be sanded smooth using fine grit sandpaper before being painted with primer and then the desired color. Lacquer-based automotive paint is preferred as it dries quickly and bonds well to plastics and metal. Depending on the desired surface finish a gloss or matte clear coat is applied over the colored base to protect the finish. If the final product has graphics such as a pad printed logo, we have these printed on waterslide decal paper as it is very thin and is a good simulation of the process.
The final prototyping stage is the factory sample. These are the first attempts by the factory to create the product using the same processes and materials as the mass produced product. There can be many rounds of factory samples and they are often denoted with a prefix “T” and the round of sampling. The first samples are called “T1” samples and so on. Sampling rounds continue until all of the issues are worked out and the factory and the customer are happy with the final specification.
It can be a lengthy and costly process to get the first factory samples, as it is the first step in the mass production process. The factory needs to create the tooling, order the material, create fixtures, and build a setup assembly area to produce the product. Deposits need to be made for all of the tooling and setup costs before any work can begin. Depending on the number and complexity of the components, it can take from 6-12 weeks or more to get the first samples.
The T1 samples are usually not very aesthetically pleasing, but it is the first chance to evaluate the product in its molded form with all of the right materials and components. Plastic molded parts are usually shot with a raw color plastic, and the mold surfaces are left unpolished and the machining marks show up in the parts. Molded parts are evaluated for their fit and integrity and examined for any mold irregularities like sink marks, flashing or odd flow marks. A document is created noting all of the issues with photos and call outs and sent back to the factory for evaluation. Each sample increases in quality as the issues get fixed. The final samples are molded in the correct colors and finishes and shipped in their final packaging, too.