How additive manufacturing can help build better products.
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It goes without saying: Innovation is inherently risky. But it’s required in a world where consumers are demanding new and updated products on shorter development cycles. In hypercompetitive markets like consumer electronics, for example, companies must constantly release new and innovative products. This can create a strain on development cycles and traditional production models. 3D printing technology, or additive manufacturing, is now gaining traction as more companies embrace 3D printing to alleviate risks in production and build better products and prototypes – fast.
But without real-world product testing, buyers could be left with broken expectations. What’s more, getting products to market fast can be the key to beating out the competition. This kind of fast-paced innovation is where rapid prototyping and production with 3D printing shines: It helps alleviate the risk of innovation and builds better products – fast.
This mode of manufacturing may only account for a tiny fraction of finished goods – 0.01 percent to be precise —but 3D printing’s impact on innovation is proving to be anything but small. Today’s prototypes can be produced using a variety of 3D printing technologies that are both fast and affordable. It’s allowing automakers to design new and lighter parts, faster than ever. It’s allowing aviation companies to reduce aircraft engines from several hundreds of separate parts to a dozen parts. And, it’s allowing medical and health care companies to customize everything from prosthetics and spinal implants to hearing aids.
Building a part in thousands of thin layers allows 3D printing to create highly complex geometries. These can often be impossible to mold—internal channels and holes that are unreachable by end mills, or entire assemblies printed as a single piece. Think of it this way: 3D printing is a good option for parts that are difficult to manufacture, and a great option for parts that are impossible to manufacture traditionally.
3D Printing can be used for:
- Production parts
- Functional models
- Visual aids
- Fit and assembly testing
- Tooling patterns and components
- Jigs and fixtures
- Concept models
- Patterns for casting.
Choosing a 3D Printing Technique
There are a growing number of 3D printing technologies and materials to choose from, but there isn’t necessarily a preferred additive prototyping process. The challenge is finding the best prototyping method for each project and for each phase of the project. Variables among prototyping methods include speed, cost, appearance, supported materials, and a variety of physical characteristics. In some cases, all you need is something you can hold in your hand; in others, fit with other components is required.
When reviewing each, make sure your preferred process can accommodate part requirements in cosmetics, materials and functionality.
- Stereolithography (SL) is best suited for early prototype parts where cosmetic attributes are important, such as fine features or smooth finishes. It’s a good fit for applications like visual aids, form and fit testing, concept models or patterns and microfluidics.
- Selective laser sintering (SLS) uses thermoplastic nylon powder, rather than liquid resin, as the foundation to build parts. This creates parts with high strength and temperature resistance. SLS is ideal for functional prototypes and end-use production parts. Example applications include jigs and fixtures, concept models and sample pieces, and living-hinge and snap-fit features for parts used in industries like aerospace, automotive and medical.
- Multi Jet Fusion (MJF) is similar to SLS technology and creates durable prototypes and functional end-use parts, but there are a few differences between the two processes. MJF offers a finer minimum-feature resolution, improved surface finish and more consistent mechanical properties. It also offers faster overall build speeds, allowing for larger part quantities in shorter time frames. Conversely, SLS provides a larger available build envelope, better small-feature accuracy, broader material selection, and multiple colors since parts can be dyed.
- PolyJet is a good fit for parts that require various levels of hardness (durometer) and multiple colors in a single part build. Other 3D-printing processes require multiple builds and secondary finishing to achieve the same result as PolyJet parts. It’s also a good option for quickly and inexpensively simulating over-molded or elastomeric parts before moving to two-material injection molded parts for concept or trade show models.
- Direct metal laser sintering (DMLS) can produce strong, nearly fully dense metal parts that, like SLS and MJF, can serve as functional prototypes or end-use production parts. The process is used for many of the applications on the market today such as medical instruments, heat sinks and aerospace componentry.
When it comes to 3D printing, it’s important to remember that there’s no one-size-fits-all solution. Each part and application will determine which technique and material is the right fit. Identify what your needs are upfront, and use them to guide you through the selection process.
While a few of the processes described can be carried out in-house, most of this prototyping is outsourced. Outsourcing allows the developer to choose the best methods for any need. That can entail using multiple prototyping methods over the course of a single project. In selecting a vendor, consider the needs and goals of your project:
- Can the manufacturer provide suitable prototyping methods for your specific needs?
- Can it help you select the best method at each stage of the process?
- Does it offer any kind of design assistance?
- If you need a series of prototypes, can the manufacturer provide continuity?
- How experienced is the manufacturer in the processes you will use?
- Can it produce the maximum quality available for each prototyping method?
- If necessary, can it provide secondary operations for your prototypes?
- If material is critical, what materials can the manufacturer offer in the selected method, and if a particular method cannot utilize your preferred material, can it offer other methods?
- What turnaround times does it offer?
- What is the manufacturer’s reputation for meeting deadlines?
What’s Next for 3D Printing?
3D printing is an excellent way to produce prototypes for concept review or form-fit-function testing. However, consider this list: Fuel nozzles for General Electric’s LEAP engine; cabin brackets for Airbus A350 aircraft; patient-specific hearing aids, and LED power-indicator housings for battling robots. This is evidence that additive manufacturing is becoming an increasingly popular method for producing “real” parts. 3D-printed end-use parts are especially useful when production volumes are low enough that casting and molding are not cost-effective, or where part complexity prohibits processes like machining.
Additive processes all share the common impracticality of mass production into the thousands and tens of thousands. Is a new frontier of additive scalability an area that additive could soon explore? According to Terry Wohlers, from independent consulting firm Wohlers Associates, Inc., medical and aerospace industries are beginning to embrace increased printed part production as well as companies in dental and jewelry fields. For a seismic shift to occur, it will likely take more than that. Currently, 3D printing plastic materials are typically 50 to 100 times more expensive than traditional manufacturing, according to Wohlers. So presently, low quantities are much more suitable for additive manufacturing. When equipment throughput increases and equipment and material decrease, the potential for larger production volumes will increase. Until then, processes like injection molding—that involve an initial tooling investment, but lower per-part price as quantities increase—remain the logical high-volume next step after prototyping.
At its core, 3D printing is empowering innovation and unlocking new opportunities in an increasingly competitive market. As this technology advances, the question isn’t whether you should consider the technology, but rather at which stage it will be the best fit.
Global Product Manager, 3D Printing, Protolabs
Greg Thompson is currently the global product manager for 3D Printing at Protolabs. Thompson has held product leadership roles at General Mills, Polaris, and Andersen Windows along with running his own successful product consulting business. Thompson holds a BS, MS, and MBA in engineering and finance.