Prototyping might feel like an unenviable part of the product development cycle, but it’s really the soul of the whole thing. The decisions you make in prototyping can have lasting consequences — and make it either vastly easier or harder to get a working product to market.
So, today, we’re going to look at the three primary methods of prototyping used currently, how they each excel and fall short and some variants and material choices you can consider for each.
With any luck, by the end, you’ll have knowledge you can use to either launch your own prototype or find a third party to help you with the task. Let’s get started.
Injection Molding
Injection molding is common and comes in many forms. You may already be familiar with injection molding using plastics and liquid silicone. If you’re weighing this prototyping process against the others, the complexity and quantity of product you wish to create are the two main factors. CNC machines can, for example, produce more complex parts — but not at the quantities made possible by injection molds.
If you anticipate dealing with large quantities, injection molding is a better choice than either 3D printers or CNC machines. Some single-cavity molds are capable of producing production runs as high as 10,000 units. Injection molding is also great if you need high repeatability in your process and want to save on labor costs.
Like other prototyping methods, injection molding offers several material choices — in this case literally hundreds of different plastics, rubbers, silicones and combinations of all three. If your prototype requires the layering of different materials, it’s possible with an offshoot of injection molding called “overmolding.”
Computer Numerically Controlled (CNC)Machining
You can guess from the name, but CNC machines use computers and digital design programs, like CAD, to produce parts.
CNC machining can turn out prototypes faster than a 3D printer — at least for now — and is better suited to larger production runs. It also has the distinction of being extremely accurate. The other processes we’ve discussed here offer solid repeatability, but CNC machining is arguably the best in this category.
In terms of materials, CNC machines might surprise you here as well. You’ve probably seen them carve through metals like copper, stainless steel, brass and aluminum as though they were butter, so it makes sense that they can be applied to plastics and thermoplastics, too.
One snag with CNC machining is that the machines that do the work can be prohibitively expensive for smaller businesses. It won’t be much of a problem for established companies, but if you don’t have a lot of money to pour into machinery when you’re just starting out, you will probably want to consider some of the other choices until you’re ready to grow your operation further.
3D Printing
3D printing is enjoying its time in the sun right now thanks to the rapid commercialization of the technology, which has helped make it more affordable. Independent hobbyists and even entrepreneurs are printing oftentimes elaborate products in their garages and basements and selling them at a profit. This may be what it looks like when the means of production become democratized.
Despite its many benefits, 3D printing is admittedly a young technology. It’s evolving rapidly, and that means “buying in” at this stage carries a certain element of risk that investing in the other prototyping methods here may not.In other words, you don’t know when a superior printer might be developed. There’s always room for innovation in the CNC field, for example, but it comes much more slowly.
It’s an assessment nobody can make but you. Nevertheless, 3D printing offers some can’t-miss benefits, some of which are extremely exciting.
A new technique called stereolithography, or SLA, makes it possible to produce extremely intricate parts in a very short amount of time. Products produced this way have a consistency like resin, though, so don’t expect them to become heirloom pieces.
Other 3D printing methods definitely can produce more durable parts — including selective laser sintering, which employs thermoplastics, and direct metal laser sintering, which allows for the printing of metal components.
Like injection molding and CNC machining, 3D printing accommodates a range of variously talented materials. Depending on what you intend to build and how you want it to perform, familiarizing yourself with the best pairings of materials to machines will help produce a product that wows your customers.
Finally, keep quantity in mind. 3D printing and CNC machining are excellent at low-volume production runs, while injection molding is the far more economical approach for mass production.
That all probably sounds like a lot to take in, but there’s a way to condense it even further: when you need to turn out prototypes, aim to work smarter instead of faster. And working smarter begins with choosing the right tools — just as it has since we invented the first chisel.
Article by —
Megan Ray Nichols
Freelance Science Writer
nicholsrmegan@gmail.com
www.schooledbyscience.com/about
