3D printing technology has revolutionized manufacturing processes in recent years. From rapid prototyping to low-volume production, additive manufacturing delivers game-changing benefits like design flexibility, shorter lead times, and reduced costs. One 3D printing method that holds great promise for manufacturers is selective laser sintering (SLS). SLS uses a laser to fuse powdered material into a solid object layer-by-layer based on a 3D model. The technology enables complex geometries, quick turnarounds, and excellent mechanical properties. But should manufacturers invest in buying their own SLS 3D printer?

In this article, we’ll dive into the key capabilities of SLS 3D printing and how it can transform production. We’ll look at the downsides to consider and when investing in an SLS printer makes sense. You’ll learn the factors to weigh when evaluating if bringing SLS in-house will deliver sufficient ROI for your manufacturing needs and competitiveness. We’ll also provide key recommendations on if and when buying your own SLS 3D printer is prudent to take your manufacturing agility to the next level.

What are the Key Benefits of SLS 3D Printing for Manufacturing?

Selective laser sintering (SLS) offers some major advantages that make it an appealing 3D printing technology for manufacturing applications. Here are some of the top benefits of SLS 3D printing:

High Accuracy and Consistency

• SLS can produce parts with high accuracy and precision. Tolerances down to ±0.005 inches are possible depending on the material and printer.
• It also offers excellent repeatability and consistency between printed parts. Each part comes out nearly identical.

This makes SLS ideal for applications like:

• Aerospace and aviation components
• Medical devices that require precision
• Automotive prototypes
• Jigs, fixtures, and other manufacturing tools

Good Mechanical Properties

• Parts printed on SLS machines have good mechanical strength and rigidity.
• SLS materials like nylon have high tensile strength and elongation break points.
• Parts can be isotropic – evenly strong in all directions.

Ideal for functional prototypes and end-use parts like:

• Functional machine components
• Durable snap fits and living hinges
• Manufacturing tools like jigs and fixtures

Wide Range of Materials

• Engineering plastics like nylon, TPU, PEEK
• Metals including steel, aluminum, titanium alloys
• Sand and ceramics for metal casting molds
• New composites and other materials constantly in development

This material flexibility lets you produce:

• Functional plastic parts
• Durable metal components
• Sand casting molds
• Ceramic cores and shells
• And more…

Minimal Waste

• The SLS process has very little wasted material.
• Any unused powder can be reused for future prints. Recycle rates over 90% are common.
• This makes SLS more sustainable and cost-effective than other 3D printing methods.

Complex Geometries with Intricate Details

• SLS can produce highly complex and organic shapes not possible with traditional methods.
• It supports intricate details like small internal channels and lattices.
• Moving parts like joints, hinges, and other assemblies can be printed as one part.

Enables innovations not possible before:

• Lightweighting topology optimized parts
• Lattice structures
• Conformal cooling channels
• Snap fits and other assemblies

Speed and Cost Advantages for Short Runs

• SLS has fast build speeds – parts print quickly at typical rates of 5-15 cm/hour.
• It provides cost advantages compared to machining, injection molding, and other methods for small batch production runs (up to 10,000 units).
• Reduces the need for expensive tooling and setup.

What are the Downsides of SLS 3D Printing to Consider?

While SLS 3D printing delivers some major advantages, it also comes with some downsides to factor in:

Surface Finish Requires Post-Processing

• The layered build process can create a rough surface finish on parts.
• Post-processing like sanding, bead blasting, tumbling, or coating is often required to smooth surfaces.
• Extra time and cost for post-processing must be accounted for.

Size Limitations

• SLS machines are constrained by maximum build volume size.
• Typical volumes range from 10 inches cubed up to 2 feet cubed for industrial printers.
• Larger parts may need to be split into sections and assembled.

Powder Materials Can Be Expensive

• The specialty powders used for SLS are more costly than filament for other printing methods.
• Materials like PEEK and TPU can cost over $150 per kilogram.
• Nanoparticle-enhanced powders and composites cost even more.

Facility Modifications May Be Needed

To handle powder materials safely:

• Powder containment systems and vacuums are required.
• Ventilation and air filtration helps control dust exposure.
• ESD prevention measures should be taken.
• May require an isolated, climate-controlled space.

Lower Accuracy Than Some Methods

• SLS accuracy is generally around ±0.005 inches depending on the material and machine used.
• Tolerances down to ±0.001 inches are possible in optimal conditions.
• But SLS is not as accurate as SLA or DLP for tiny, delicate features.

Requires Skilled Operators

• SLS printers need proper operation and maintenance by trained technicians.
• The preprocessing of files and powders takes specialized knowledge.
• Lack of expertise can result in print failures and other issues.

So those are some of the key downsides and limitations to be aware of with SLS technology. But for many applications, the benefits outweigh the drawbacks.

What Are the Key Considerations When Buying an SLS 3D Printer?

If you decide that bringing SLS 3D printing in-house makes sense for your manufacturing needs, there are several key factors to consider when selecting a printer:

Required Build Volume

• The build volume dictates what size parts and how many you can print at once.
• Consider the largest parts you will need to produce. Go bigger if you can afford it.
• Build volumes range from small 10” cubes up to 2 feet cubes.

Desired Materials

• SLS printers use proprietary powders tailored to their process.
• Common materials include:

– Plastics – Nylon, TPU, PEEK, PP, other engineered plastics

– Metals – Steel, aluminum, titanium alloys

– Sand or ceramics – For casting molds and cores

• Consider your material needs – plastics, metals, sand molds, etc.

Required Resolution and Accuracy

• Accuracy ranges from ±0.005” to ±0.0015” for dimensional precision.
• Thinner layers down to 0.001” can improve surface finish.
• Assess the resolution and precision suitable for your parts.

Cost Considerations

• Industrial SLS printers range from $100,000 to over $1,000,000.
• Factor in material costs of $50-$150+ per kilogram.
• Operating labor, maintenance, software, and post-processing also add costs.

Software Capabilities

• User-friendly software with robust tools for preparing and optimizing files is key.
• Remote monitoring features can provide peace of mind.
• Compatibility with common CAD programs is ideal.

Installation and Operation Requirements

• SLS printers need space for installation, powder handling, and post-processing.
• Proper ventilation, cooling, and powder containment is critical.
• Technician operation and maintenance is required.

Certifications

• Certifications like ISO or UL for aerospace, medical, and other regulated industries may be required.

So those are the key factors and considerations when investing in an SLS printer for your manufacturing needs. Analyze each criteria closely for the best selection.

When Does Buying an SLS 3D Printer Make Sense for Manufacturers?

When does investing in an in-house SLS 3D printing capability make good business sense? Here are some of the top scenarios where buying your own SLS printer can pay off:

For Short Run or Custom Production

• The low volumes where SLS is cost-effective vs injection molding or machining is approximately 1-10,000 units.
• SLS excels at short runs for custom, low-volume parts. No need for costly molds and tooling.

When the Benefits Outweigh Outsourced Costs

• Weigh SLS part production costs from service bureaus vs your in-house costs.
• Calculate your break-even point where in-house SLS printing becomes more economical.

To Enable Mass Customization

• SLS allows easy customization and personalization of each part you produce.
• Ideal for mass custom products, personalized medical devices, and more.

For Rapid Prototyping and Development

• Speed up product development cycles by rapidly iterating prototypes.
• Avoid delays and costs of working with external vendors.

If Accuracy, Speed, and Properties Are Critical

• When dimensional accuracy, fine details, material properties, and quick turnaround are imperative.

For Complex Geometries

• If you need to produce complex organic shapes, lattices, or internal channels not possible with other methods.

If You Can Leverage Material Reuse

• Since SLS powders are reusable, having in-house capabilities can yield significant material savings.

So in summary, if you can truly leverage the strengths of SLS for your products, buying your own printer may be advantageous. The key is analyzing if the benefits outweigh the substantial investment.

Key Takeaways – Do You Need to Buy an SLS 3D Printer?

Should you invest in an SLS 3D printer for your manufacturing needs? Here are some key takeaways:

Carefully Analyze the Benefits For Your Specific Parts

• SLS can produce complex geometries with good mechanical properties out of various materials quickly and accurately.

• But the printers are expensive and require special facilities, skilled operators, and post-processing.

• Thoroughly assess if the SLS capabilities align with your specific part requirements and quantities.

Understand Your Break-Even Cost Point

• Weigh the projected long term costs of outsourced SLS printing vs buying your own printer.

• Realize most printers have a long ROI payback period of over 2 years.

• Calculate the break-even point where owning your own SLS system becomes economical.

Factor in the Learning Curve and Expertise Required

• Having in-house SLS involves a learning curve to master the process and software.

• Working with powders requires specialized knowledge and safety measures.

• Lack of experience and training can lead to print failures and other issues.

Compare to Outsourcing SLS Part Production

• Using a specialized SLS 3D printing service bureau may be more practical in some cases.

• They handle materials, offer expanded build volumes, and possess expert knowledge.

• For lower volumes, outsourcing may be more cost-effective.

Buying May Make Sense if Critical to Competitiveness

• If SLS capabilities are truly critical for next-gen products, rapid prototyping, or customization.

• When you can leverage SLS benefits like designs, speed, and materials that set you apart.

So weigh all factors carefully before making the SLS 3D printer investment. For the right applications and volumes, owning your own system can be a strategic advantage.