Rapid Prototyping: Introduction Guide

Haven’t you thought to yourself about the history behind every mass-produced object around you? Something that began in someone’s mind, someone’s imagination, is now in the palm of yours and countless consumers hands. To make mass production possible, manufacturers had to put lots of thought into an arduous design process to meet their intended requirements. Moreover, launching a production line is costly and risky!

So, how do you make that transition from paper to actual production smoothly and safely? Well, you must build confidence first with a prototype. Indeed, one of the main reasons for unsuccessful design projects is, undoubtedly, that not enough prototypes were made.

Then, what is a prototype in the first place? Why exactly should you engage in a prototyping process? We’ll try to answer these predicaments in this article. Furthermore, we’ll explore the phenomenon known as rapid prototyping and how it helps designers worldwide boost development times significantly.

What is a Prototype, and Why We Do It

A prototype is a sample to test a product’s features and requirements during its development. Designers can put their ideas into trials throughout prototyping processes to gauge feasibility and highlight problems.

You can take scientific experimentation as an analogy; a theory is worthless without being proven in a real-life scenario. Actually, having the wrong design criteria thrown directly into production can lead to catastrophic consequences. Product recalls, lots of time and money lost, potential hazards, and legal demands can be avoided with plenty of confidence in an idea.

Prototyping is an iterative process; you must make as many as possible as you refine the design, get feedback from potential users and enhance precision. So, we can say it isn’t a linear nor an isolated process, rather a constant feedback loop throughout all the stages of production. Depending on which stage of development you are in, tools, methods and problems are different. Some prototypes can be made with off-the-shelf hardware, while fully functional builds with customised components are necessary at higher stages.

Getting your design right might be frustrating; this is why designers should put lots of energy into prototyping, to the point of even laying more effort into it than the design itself. The best prototype is not the most successful but the one that better answers questions and moves the design forward.

Now, prototyping lowers risks, but as you iterate and refine, costs accumulate. How do you optimise the balance between risk and costs? In reality, it mainly depends on good and experienced judgement. Still, as new innovations in techniques, processes, and materials occur, new possibilities to streamline your decision-making process appear. Such is the case of rapid prototyping.

Rapid Prototyping, 3D Printing and Virtual Prototyping

As engineering and design workflows shift into digital tools, the paradigm of taking tasks within a project significantly changes. CAD modelling has completely transformed how we manage design data, while CNC automation enables us to bring it to reality quickly and seamlessly. And this is where rapid prototyping comes into place, a streamlined process where you can create an accurate representation directly from your design data.

The Importance of 3D Printing

So, what counts as rapid prototyping? Well, any subtractive CNC technique or additive process qualifies. However, 3D printing is the rapid prototyping process by excellence due to its simplicity, versatility in design and friendly costs. Perhaps the best part is its self-sufficiency; it does not require tooling. So, as versions get further refinement and closer to the final product, materials of choice become more customised. Thus, costs per iteration increase significantly.

However, more than the material used, the main issue lies in building the tools to process it. For example, to prototype an injection moulded part, you must create a mould just for short-run models, which can be risky, prohibitively expensive and extremely time-consuming. In the end, having the prototyping costs substantially greater than the final product itself might be daunting for developers.

As 3D printers capabilities and material choices improve, this technology can reproduce increasingly higher fidelity replicas to the final product, reliable enough for testing and without going through all that hassle that tool-making embodies. Of course, 3D printed parts still have their limitations and might not always be the better answer for some applications, so, instead, CNC machining might be the better choice.

Most importantly, 3D printing can be used not only to prototype the product itself but the tools and processes surrounding it. You can create soft-moulds for urethane, investment, and sand casting from 3D printed patterns, jigs and fixtures and even short-run injection moulds before committing to the real deal.

Virtual Prototyping

Now, we go a step further. What about testing your design without even needing a physical prototype? As computer modelling capabilities become increasingly accurate each year, it can be a practical choice to simulate the aspects of a product through software. Today more and more companies find it feasible to use virtual prototyping as a partial and even as a complete alternative to physical prototypes.

Once the 3D model is at hand, there’s plenty of things you can do with it. The following are some prominent examples:

• Simulations like FEM and CFD can provide valuable information on how the product might perform under specific conditions
• Photorealistic renderings are ideal for seeing how the product would look. Project managers use it as marketing tools to transmit the concept to potential users and investors
• Injection moulding simulations are ideal for testing manufacturability
• Motion studies
• Virtual reality is increasingly employed for user experience trials

Nevertheless, virtual prototypes have their limitations—for instance, ergonomics. A virtual object can’t be touched. Most certification standards require physical testing, and for a good reason. How can you be entirely confident that a mathematical model represents reality and all its complexities? Again, virtual prototyping tools are at our disposal to significantly lighten and improve our work, but as it happens with every tool, making the best out of it depends on having a sound judgment. And, now that we mention judgement, let’s point out some important stuff.

Finding the Balance Between Rapid and Traditional Prototyping

It is undeniable the benefits that, thankfully, rapid prototyping provides nowadays. However, sometimes the hype for something can cloud our judgement. Rapid prototyping techniques may not always be the best answer in some cases. There’re some drawbacks of rapid prototyping you must earnestly consider before taking action.

3D printing enables exceptional design freedom, and that’s great. But this can lead people to often engage in unrealistic geometries. What’s the benefit of printing a prototype that isn’t manufacturable through more conventional mass-production processes? Designers must be careful about this.

The other thing is that some prototyping solutions can be done with simpler stuff. For instance, why would you invest in 3D printing when you can just use off the shelf materials like foam, wood, cardboard to test basic concepts faster, cheaper and more efficiently?

Lastly, before buying a rapid prototyping machine, you must wisely choose what solution adjusts better to your particular application. But, where to start now that countless solutions are continuously appearing in the market as we speak? Is it worth making such a substantial investment? How do we make the best out of it? Well, the team at Solid Print is here to help you make optimal prototyping decisions for your design project. For more information, please call SolidPrint at 01926 333 777 or email info@solidprint3d.co.uk.

In a subsequent article, we’ll go deeper into the prototyping process and explore what happens at each stage of development. How does an initial proof-of-concept differ from a pre-production prototype? How does rapid prototyping solutions respond to specific prototyping aims? We’ll deal with these questions and more!