Prototyping and 3D Printing: The Complete Fundamentals Guide

When developing a physical product, it's essential to be aware of the various prototyping methods at your disposal. Prototypes serve as indispensable tools for testing and refining ideas before transitioning to full-scale production therefore, understanding the different prototyping methods can save you valuable time and resources.

So, what are these methods and how do you choose the one that's right for your project? Here is a breakdown of the 4 main methods of prototyping that we have experienced as physical product design and development experts:

1.) Rough Mock-Ups:

These are generally low-fidelity prototypes that provide a basic representation of the product’s form with minimal functional components. What makes rough mock-ups valuable is their speed, allowing for numerous iterations to be made and assessed without taking too much time - they are quick and dirty with limited attention to minor details. The purpose of a rough mock-up is to visualise, evaluate and validate the overall shape and size of the product in reality.

Example of a very quick mock-up to establish a rotation point for 2 components that interact with each other. Read the case study here.

2.) Aesthetic/Looks-Like Model:

This method focuses on replicating the appearance and aesthetics of the final product and is more refined than a mock-up. Although these models look like the final product, they don't aim to function like one. With many consumer products, look and feel can be the key commercial driving factor behind a purchase so it is important to work on this through the development of appearance models. These can often include realistic textures, colours, finishes or decorations to look like the intended materials.

Example of an aesthetic/looks-like model using dyed powder bed-based 3D printing with bristles manually added to create a realistic aesthetic. Read the case study here.

3.) Functional Prototype:

A working model of the product that demonstrates functions and features. It may use a different material or level of finish than a final product but it's designed to demonstrate how the product works. By temporarily ignoring visual appearance throughout this process, you can devote all of your attention towards making sure that the product functions flawlessly. We would say this is one of the most important stages in product development.

Left: Quick FDM print to prove the concept’s functional principle. Right: Higher fidelity prototype combining a variety of processes and materials which closely represents the final product. Read the case study here.

4.) Factory Sample:

Closely resembles the final product in terms of materials, finishes and functionality before proceeding with tooling and production. Regardless of the meticulous CAD and engineering work, a sampling stage is always necessary, either through a manufacturer or a professional prototyping company. Achieving a factory-level sample requires careful attention to both form and function. The outcome is often used for quality control, production testing and as a reference for manufacturing.

Example of a first sample from the manufacturer with the intended materials and finishes. Read the case study here.

These are some of the most common methods but there are more that serve different purposes. Depending on the stage of development and the complexity of the product, the choice of prototyping method can make all the difference.

Beyond knowing the prototyping methods, it is also important to consider the crafting/production processes and materials that can be used to create them.

Prototypes can be made in a variety of ways - paper, cardboard, silicone moulding, clay modelling, subtractive (CNC), foam modelling, etc. Among these methods, 3D printing has emerged as one of the most popular choices due to its versatility and efficiency. It is one of the best ways to mock up and test your product to assess its validity but with so many methods of 3D printing, how do you know which one is right for you?

It all depends on the specific application needs, your budget and the speed of production required. Choosing an unsuitable method may be counterproductive. To simplify, here are the three main categories of 3D printing processes:

1.) Filament Extrusion Based (e.g. Fused Deposition Modelling - FDM):

• How it functions: Melts and deposits filament layer by layer to build objects.

• Benefits: It's cost-effective, versatile with material choices and can produce durable parts.

• Limitations: Surface finish may not be smooth and complex shapes might require support structures.
  

Example: Quick FDM print of a housing to test the fit of internal components.

We have used a variety of FDM printers for both mock-ups and functional prototypes. The Bambu Lab H2D has been a reliable tool for us over the past four years. It's a well-rounded and powerful printer for a very reasonable cost. PLA is the main type of filament we use as it gets the job done for the majority of quick prototypes (grey in colour as it shows details well in photos).

2.) Photosensitive Liquid Resin Based (e.g. Stereolithography - SLA):

• How it functions: Solidifies liquid resin with a UV laser, creating highly detailed and accurate parts.

• Benefits: Ideal for intricate designs, smooth surfaces and a range of resin materials.

• Limitations: Equipment and resin costs can be higher and post-processing can be messy.
  

Example: Intricate internal component that needed to avoid support material in various areas of the part.

For more detail-sensitive parts that need a little bit more accuracy and a finer finish, we used the Anycubic Photon Mono X for many years. This printer is also cost-effective and powerful. Like many resin-based 3D printers, post-processing can be somewhat time-consuming and messy. Regardless, the results are impressive, with the capability to create exceptionally accurate parts.

3.) Powder Bed-Based (e.g. Selective Laser Sintering - SLS):

• How it functions: Fuses powdered materials, like plastics or metals, layer by layer with a laser.

• Benefits: Excellent mechanical properties, complex geometries and multiple material options.

• Limitations: Equipment costs are typically high, post-processing involves powder removal, and surface finish may need extra work.
  

Example: Testing a snap-fit feature using a combination of MJF and SLS 3D printing.

Overall, there are many ways to create prototypes in a wide range of materials and finishes. Assess your use case and select a suitable process to get the most out of each part.

So, whether you're in the early brainstorming phase or gearing up for production, keep in mind that the right prototype can help guide you to product success! If you’re confused, get in touch with us to see how we can help.