3D Printing Fully Functional Parts with Selective Laser Sintering

Selective laser sintering (SLS) is an industrial-grade 3D printing process. It builds durable nylon prototypes and functional parts using a laser that “draws” slices of a CAD model in a bed of material, fusing micron-sized particles one layer at a time. The result is fully functional plastic parts that might have been otherwise challenging to manufacture using machining or injection molding.
This month’s tip discusses:

  • Properties and applications of various nylon materials
  • Managing the SLS build process
  • Design elements to improve eventual moldability
  • Surface finishes and post-processing
  • Maximum part size, achievable tolerances and other considerations.

Read the full design tip here.

TIPS WITH TONY: LSR Offers Design Flexibility

There are many reasons why you should be looking at liquid silicone rubber (LSR) — I’ll highlight a few big ones in order to get you thinking about this versatile thermoset.

For a deeper dive into LSR and how it’s used in the lighting industry, please attend my free tech talk webinar hosted by Tech Briefs.

LSR Molding
LSR parts are formed in process similar to that of conventional plastic injection molding with one main difference. LSR is a thermoset material that compounds two liquids together, which is then heat cured in the mold to produce a part. The material delivery system is cooled and only the mold is heated. This is unlike thermoplastic molding, which begins with the melting of plastic pellets that are injected into a heated mold.

Optical LSR is highly flexible and can replace glass in many lighting applications.

LSR Advantages
LSR parts are strong, elastic, chemical resistant, serializable and biocompatible, and have a range of operating temperatures. The benefits of LSR lend itself well to the automotive, medical and lighting industries where gaskets, seals and lighting lenses are frequently used.

LSR parts have a very good temperature resistance, ranging between -49°F to 392°F; they are non-yellowing, UV stable and optical LSR has up to 94 percent light transmission; they offer good vibration control and offer up to 400 percent flexibility along with excellent part memory.

The chart pretty much speaks for itself when comparing LSR to PC, PMMA and glass when looking at replacing the traditional materials with LSR.

Design Flexibility
Traditional thinking of part design needs to be considered, but many can be broken:

  • Part thicknesses greater than 1 in. and less than 0.020 in. are achievable with little to no concern of any unsightly sinks or internal voids.
  • No ejector pins are used to remove parts from the mold as they are all hand-removed.
  • Gates are nearly invisible, barely thicker than flash. LSR flows like water, so the gate needs to be very shallow, but wide.
  • Negative draft angles or increased undercuts are a possibility with up to 400 percent part flexibility and part memory.
  • Ability to fill fine details or voids.
  • Ability to combine components reducing number of parts to assemble, e.g., combining a lens and seal for lighting applications.

For more information on LSR, please download our white paper or listen in to my tech talk presentation mentioned at the top of the tip. You can also visit our website at protolabs.com or contact one of our customer service engineers at customerservice@protolabs.com or 877.479.3680 with additional questions on any of our services.

EYE ON INNOVATION: Mfg. Day Highlights Industry’s High-Tech Future

In a recent GE commercial, the parents of a young, bespectacled software developer, implore him to accept his “grandpappy’s” giant sledge hammer, now that he’s working in manufacturing for GE.

The flustered son tries to explain: “Yes, GE makes powerful machines. I’ll be writing the code that allows those machines to share information with each other.” The baffled parents just don’t get it. See for yourself:

The spot effectively shows the quantum leap manufacturing has taken. In fact, as the Huffington Post reports, the global manufacturing sector is in the midst of what many manufacturing experts regard as the Fourth Industrial Revolution, known globally as Industry 4.0. Continue reading


Proto Labs has a knowledgeable support staff able to answer nearly any manufacturing question you toss their way. If you haven’t already spoken to them, you should get to know our customer service engineers (CSEs) who can help guide you on your next additive manufacturing, CNC machining and injection molding project.

This is Tony from the popular blog series, Tips with Tony. He was a CSE for years and is now Proto Labs’ go-to technical specialist.

It’s challenging to assemble the top five most frequently questions asked — it should be more like a top 100 questions asked on a daily basis. But, I whittled it down to the top questions our CSEs are most frequently asked.

5. How many parts can you produce and how fast can I get them?

Additive Manufacturing
SL, SLS and DMLS:  1 to 50+ parts in 1 to 7 days

CNC Machining
Milling and Turning:  1 to 200+ parts in 1 to 3 days

Injection Molding
Plastic: 25 to 500 sample parts in 1 to 15 days with low-volume production of 10,000+ parts available

Liquid Silicone Rubber (LSR): 25 to 500 sample parts in 1 to 15 days with low-volume production of 5,000+ parts available

Metal: 25 to 100 sample parts in 10 to 15 days with low-volume production of 5,000+ parts available

Magnesium: 25 to 100 sample parts in 15 days with low-volume production of 5,000+ parts available

Please note that lead times are dependent on part size and current workload. As such, not all parts are eligible for a one-day turn and expedite fees may be applied turnaround times faster than standard delivery.

4. What manufacturing method(s) should I use?
First, let me ask you these questions to help you decide:

  • How many parts do you need?
  • Are these functional, cosmetic or just something to hold in your hand?
  • Do you know the material you want?
  • What type of finish do you need?

If you have a part total in mind, you can begin narrowing down the manufacturing method to either injection molding (for higher volumes) or additive manufacturing or machining (for lower volumes). Identifying the material you need will then allow you to narrow down your decision even further. Beginning with any one of these questions will start you down the correct path towards the proper manufacturing method.

Continue reading

EYE ON INNOVATION: Regrowing Damaged Nerves Using 3D Printing Technology

A national team of researchers has developed a 3D-printed guide or pathway that helps regrow complex injured or damaged nerves, and successfully tested the guide in rats.

Researchers say that this groundbreaking research holds the potential to help more than 200,000 people annually who experience nerve injuries or disease. The researchers are from the University of Minnesota, Virginia Tech, University of Maryland, Princeton University and Johns Hopkins University. The team’s study was published this month in the journal Advanced Functional Materials.

Image courtesy of Michael McAlpine, University of Minnesota College of Science and Engineering.

Researchers used a combination of 3D imaging and 3D printing techniques to create a custom silicone guide or pathway implanted with biochemical cues to help nerve regeneration. Continue reading