Rapid Prototyping

While every product starts out with an idea, several different processes are involved in turning the idea into a user-friendly product. Without a well-planned development process, the best product idea will remain – just an idea.

Prototyping is a crucial step in turning your idea into a product. It gives you physical proof of your product’s feasibility and makes it easier to spot design flaws. Concept models can be hand-made or rapid prototyped.

This article will discuss rapid prototyping, the techniques involved in building prototypes, their use cases, the advantages of rapid prototyping, and necessary steps involved in building a prototype.

What is Rapid Prototyping?

Rapid prototyping describes the process of quickly building components without the use of expensive tooling and long lead-times. The processes can include additive prototyping (3D printing), subtractive prototyping (machining) and even low volume soft tool molding such as cast urethane molding.

Rapid prototyping is often defined as the speedy manufacturing of products with improved technical processes. As a result, rapid prototyping techniques have helped inventors, startups, and well established companies quickly innovate and develop new products at a much faster rate than was previously possible.

Is Rapid Prototyping the Same as 3D Printing?

Although the phrase has been used interchangeably with Rapid Prototyping and 3D Printing, they actually aren’t necessarily the same thing. It’s kind of like how a square is a rectangle but a rectangle isn’t necessarily a square. 3D printing or additive manufacturing is the process involved in making a physical object from a three-dimensional digital model, while rapid prototyping utilizes different, innovative technologies — CAD (Computer-aided design) files and processes such as 3D printing to achieve a cheaper, faster production process. Rapid prototyping can be used to describe multiple different prototyping processes including 3D printing (additive manufacturing), CNC machining (subtractive manufacturing), and soft tool mold manufacturing. It can also be used to describe the process of creating quick-hand built models out of various materials such as foam, and modifying and adapting existing components.

Types of Prototypes in Product Design

Prototypes of various forms are used, depending on the production stage. Each of these prototypes serves a unique purpose for the design team, who look to test for specific characteristics on their journey to the final product. Typically, the closer a prototype gets to being ready for production the more it will cost. The three major types of prototypes used in product design are:

1. Feasibility Prototypes

Rapid prototyping companies use these prototypes early in the product development process to decide whether a product is feasible or not. They are used to validate a proof of concept and provide the qualification needed in later stages of the development.

2. Low Fidelity Prototypes

Fidelity in prototyping explains the degree of accuracy required from a prototype or 3D print. Therefore, low-fidelity prototypes don’t look exactly like the actual product but are used by the design team to showcase concept models of the product.

Low Fidelity Game Controller Prototype

A low fidelity prototype is often made from hand-formed or CNC cut foam, retrofit off-the-shelf (existing) components, or from rough CNC machining or 3D printing processes. Low-fidelity 3D printed components are typically low resolution with a greater distance between print levels compared to high resolution 3D prints. While they are easier to create, low-fidelity prototyping is used early in the development cycle where complete functionality of the product is not required.

3. High Fidelity Prototypes

High fidelity prototypes are parts that are made in low quantities, and quickly (in the case of rapid prototypes) to accurately demonstrate the fit, form AND function of a product. High-fidelity prototypes are as close to production parts as you can get and in some cases they’re used for production, end-use applications. These types of prototype parts are the most costly, but they’re also the most accurate.

A high fidelity prototype smartphone undergoing user testing

A high-fidelity prototype allows designers to create a realistic model of the product. They often have complex design features and are used by rapid prototyping companies for usability testing. They can also be used to get user feedback.

Use Cases for a Prototype

Prototypes can be a valuable tool across all stages of the product development process. Some of the most common use cases for rapid prototypes are:

1. Validating New Product Ideas or Concept Models

Prototypes are often used to validate concept models early in developing a product to determine the best concept model for customers. Upon discovering the best concept model, the designer can meet the users’ needs and expectations even before production begins.

2. Testing New Features

Rapid prototyping can be used by a design team looking to test out new features or perform functionality testing. Rather than jump to mass production, the development team can create a low-fidelity prototype for initial form factor validation, or a high-fidelity prototype for designers and users to test and validate.

In addition, developers can use this process to identify issues and pain points in the product and develop a proof of concept for rapid manufacturing.

3. Market Validation

A design team can use prototyping processes to achieve market validation from users even before a product is launched. A low volume can be produced and distributed to a select group of users who interact, test, and validate the product.

After market validation, the product is ready for production manufacturing. However, if there is negative feedback about the product, the final product can be modified and improved using user feedback. Market validation will give the design team a final product to continue production manufacturing.

4. Getting Investor Feedback

A prototype test is not only used to get users’ feedback but can also be used to get feedback and support from potential investors. For example, a rapid prototype can be presented to angel investors and venture capital firms to encourage their involvement in the development cycle.

5. Assessing Product-Market Fit

Sharing your prototype with potential users is a great way to gather valuable feedback, carry out functionality testing, and evaluate your product-market fit. In addition, design teams can use prototype testing to see how well your product meets your target audience’s needs, and identify growth opportunities.

Steps to Building a Prototype

Building a prototype is essential for companies looking to launch a new product or update an existing product design. The following steps should be applied in building product prototypes.


1. Idea

Starting with the idea or concept of a product helps to create a better product outflow and saves time. Before building a prototype, the design team should identify the basic functionalities to solve pre-identified users’ problems.

2. Create a Concept Sketch

Early in the production cycle, creating a concept sketch will be invaluable in building a prototype. First, sketch out your idea to help you imagine more clearly what your product will look like and what components it might have. Concept models are mostly rough hand-drawn sketches that can be iterated quickly.

Proof of concept for a jaguar

3. Develop a Digital Prototype

Using hand-drawn sketches as a guide, a design team can create digital prototypes (3D CAD models) of the product. SolidWorks, Onshape, and Inventor are top-rated software programs used to create 3D CAD (Computer-Aided Design) models.

Proof of concept for a jaguar using AR/VR

Converting sketches to CAD files will be invaluable in creating a detailed manufacturing design and to quickly adjust parameters of the design to improve form, fit, and function. These CAD files can also be converted into a 3D rendering or a 3D print to give you a multi-dimensional, realistic look at the product. Because of the technicality involved, creating a professional 3D print should be done by a rapid manufacturing company.

4. Create a Fully Functional Prototype

A fully functional prototype, or high-fidelity prototype, should be created without compromising functionality. All functional requirements should be met and the prototype should be as close as possible to a production manufactured product. Prototyping processes help a design team to analyze the cost, feasibility, and marketability of the product. Then, the interactive prototype can undergo a testing phase with limited users to get feedback and discover areas that can be improved before product launch.

A functional prototype of a jaguar

5. Incorporate Feedback and Finalize Your Product Design

This is the final step before the finished product is mass-produced. After integrating all necessary feedback, have a functional prototype that represents what the product will resemble and exactly how it will work. A product development company that offers 3D printing can help you cut costs both in the production and testing phases.

Types of Rapid Prototyping Techniques

While there are different prototyping techniques, they can be organized in two main groups. One is additive manufacturing (3D printing) and the other is subtractive manufacturing (CNC machining and routing).

1. Additive Manufacturing

Additive manufacturing is commonly known as 3D printing. Additive manufacturing involves the production of 3D models from CAD files and builds a part layer by layer. The major types of additive rapid manufacturing used are:

I. Stereolithography SLA

Stereolithography SLA is an additive manufacturing process used for creating solid parts from CAD files. The SLA process uses a laser to cure a liquid resin layer by layer and the 3D print resolution is equal to the layer thickness.

3D Printer – Stereolithography SLA

Stereolithography SLA is known for having the highest resolution and accuracy compared to other types of 3D printing processes. SLA parts also have the smoothest finishes.

II. Selective Laser Sintering SLS

Selective Laser Sintering SLS is an additive manufacturing process that involves laser sintering small particles of plastic, ceramic, or glass into a solid model using a high-power laser. SLS is ideal for creating complex geometries and durable parts. SLS prototypes tend to be less brittle than SLA prototypes, so functional features like snap fits are possible.

Selective laser sintering part with complex features

Selective laser sintering SLS is the most popular additive manufacturing technique for professional prototypes. While this prototyping process may not yield parts as smooth as Stereolithography SLA, SLS produces strong, functional models.

III. Direct Metal Laser Sintering DMLS

DMLS is a type of additive manufacturing or 3D printing used in building rapid metal prototypes and production parts. This metal prototyping involves sintering (fusing) multiple layers of powdered metal together with a laser.

3d printers – Direct Metal Laser Sintering DMLS

The process is repeated for each layer of metal until the product model is completed. After that, the surface is brushed and heat-treated to relieve any stresses. As a result, products from metal prototyping achieve almost 100% denseness.

IV. Fused Deposition Modeling FDM

Fused Deposition Modeling FDM is an additive manufacturing process used to build models by melting and extruding plastic filament through a nozzle. A bead of plastic is deposited, filling a 2D cross-section of a part, and building the part up layer by layer. Fused deposition modeling is the cheapest and most commonly used form of 3D printing. It can be used for professional printing applications but it’s mostly used by hobbyists.

When compared with other plastic 3D printing processes, fused deposition modeling has the lowest resolution and accuracy. Something that should be considered with FDM parts is they’re weakest between layers so they’re susceptible to breaking when loading is applied in plane with the print layers. When product development companies want to produce parts that are stronger and have more omni-directional strength they use SLS, and when they need better resolution and surface finish they choose SLA.

V. Binder Jetting

Binder jetting is a prototyping process used for making parts specified by 3D CAD files. The binder jetting process uses two materials; a powder-based material and a binder (typically liquid).

Schematic representation of binder jetting

An industrial printhead selectively deposits a binding agent (binder) onto a thin layer of powder particles. After that, the material to be bound is lowered on its build platform, and parts are formed layer by layer like other 3D printing processes. After each layer has been formed at the part has been left to cure, the part has to be heated and sintered in a furnace and infused with bronze. Binder jetting is the fastest form of 3D printing for metal prototyping.

2. CNC Tools

Computer Numerical Control or CNC tools are used in most prototyping and mass production processes. CNC machines can handle the entire manufacturing process for adding materials and subtracting from them. Whether you’re making a 3D printed part, or machining a part from a blank of material, a CNC machine is being used. CNC machines can be used to process plastics, soft metals, hard metals, wood, acrylic, stone, glass, and composites. More complex CNC machines are required for tooling, handling, positioning, and processing in specific manufacturing processes.

CNC Machines for cutting ceramic tiles

Advantages of Rapid Prototyping

While it is common knowledge that rapid manufacturing has helped companies get better products to market faster than their competition, what are the advantages of the process?

1. Save Cost and Time

With 3D printers, a company can avoid the cost and time involved in building hand made models for functionality testing. 3D printing also allows people to avoid making prototypes with expensive tooling because there are no tooling costs with 3D printing and machining. With relatively low cost and time, 3D printers can help quickly go through design iterations and perform testing until an ideal design is found.

2. Communicate Ideas Effectively

While digital models offer great flexibility, physical models help design teams to more concretely share their concepts with colleagues, clients, and collaborators. In addition, when users interact with a 3D model rather than a digital interface, they can give clear, actionable feedback based on real world testing.

And for every manufacturer, getting feedback and design tips through usability testing is crucial in understanding user needs and then refining and improving their designs.

3. Work Out Concepts Faster

Prototyping processes elevate initial ideas to low-risk concept models that look like real products in no time. It allows designers to go beyond virtual visualization, making it easier to understand the look and feel of the design and compare concepts side by side.

4.Design Iteratively and Instantly Incorporate Changes

Thanks to prototyping processes, companies can make multiple iterations of a product, in as little time as one working day. Adjustments can easily be made to the digital prototype and reprinted with 3D printers upon receiving feedback and design tips.

5. Test Thoroughly and Minimize Design Flaws

In product development, flaws in a product can be expensive – the overheating of the Galaxy Note 7 cost Samsumg $17 billion in sales. Prototypes help a company carry out usability testing on multiple iterations of a product before the finished product is put on the market. So it’s critical not to rush or cut corners with the product design iteration and prototyping process.

In Summary

Prototyping processes have helped companies get better products to market faster than their competition. Manufacturers can now create prototypes within a day and carry out multiple iterations of design, form factor study, assembly and functionality testing. Understanding the advantages of rapid prototyping and knowing which process to use for different design projects will directly affect a product development company’s time to market and development cost.

After the physical product, application, or software prototype has been created, the functionality of the product is tested. If the product does not meet the set functional requirements, then the product design process should be iterated. However, if the product does meet all functional requirements, then you can proceed to commercialization.