Guide to 3D Printers
FDM vs SLA vs SLS Printers
Scott Gabdullin
Updated on October 17, 2024
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3D printing, also known as additive manufacturing, reduces costs, improves efficiency, and exceeds the limitations of product design fabrication procedures. From conceptual models to functional interfaces, fixtures, jigs, and end-use components in production, 3D printing techniques provide adaptable solutions for various applications.
3D printers of high quality have recently become more user-friendly, inexpensive, and reliable than ever before. Therefore, 3D printing is now available to more enterprises. However, considering there are numerous 3D printing techniques available, choosing the right one for you can be challenging.
What technology is appropriate for your specific application? Which materials are accessible? What are the prerequisites in terms of training and tools? How about the expenses and rate of return?
This post will compare three of the most prominent 3D printing technologies available today: FDM, and SLS vs SLA. Continue reading to learn more!
What Is FDM?
FDM is often used in consumer-level 3D printing, thanks to hobbyist 3D printers’ popularization. It utilizes thermoplastic materials, often in the sense of filament spools. The head of the printer’s heated nozzle liquefies the material, which is placed layer after layer onto the build surface via the printing nozzle.
FDM is compatible with various thermoplastics, including PLA, ABS, and their different mixes. The approach is ideally suited for simple conceptual-based models. Also, you can use it for the rapid and inexpensive fabrication of prototypes of simple components, including those often machined.
FDM has the least precision and detailing compared to SLS and SLA, rendering it unsuitable for printing detailed designs or sophisticated pieces. Both mechanical and chemical polishing procedures can yield better results. FDM printers for industrial applications can overcome these concerns by using dissolvable carriers, but they are quite expensive.
Designing For FDM
You can only design for FDM printers with 3D computer graphics or computer-aided design (CAD) software. Unfortunately, this technology has some difficulties with overhangs, hollow pieces, and undercuts. Therefore, you must create and manufacture support elements like webs, boxes, and ceilings before printing the models.
The models are analyzed by software, creating appropriate support structures based on their shape. A single extruder FDM 3D printer generates supports using the same material as the model itself, thus reducing the need for additional material. In this scenario, you should separate them mechanically.
Today, devices with two or more extruders are becoming increasingly prevalent. It enables the use of support material that’s soluble in water. However, the procedure is lengthy and occasionally requires other substances, such as citric acid.
Note that not all printing materials adhere to the dissolvable support material. Another crucial aspect is the model positioning on the generating platform. You should position the model in a manner that doesn’t necessitate a substantial number of supports.
Pros
- Non-hazardous, though certain filaments, such as ABS, emit poisonous fumes; typically, the technology is eco-friendly.
- Low-to-moderate equipment expenditures
- Wide selection of inexpensive, vibrant printing materials
- High efficiency
- Low to moderate post-production expenses (surface finishing and support removal)
- The components have virtually no permeability
- Ideal for medium-sized items
- Materials with superior structural support, heat, water, and chemical resistance
- Relatively large construction volume (600 x 600 x 500 mm) relative to other desktop innovations
Cons
- The anisotropy in material qualities caused by the additive layer process makes printed elements the poorest in the vertical build plane
- Limited design alternatives; in a vertical direction, it’s impossible to generate sharp edges, thin walls, or acute angles
- Supports required
- Poor precision, with an error range of just 10 to 25 microns
- Hard to regulate development chamber temperature, which is critical for optimal outcomes
- Injection-molded material has a tensile strength of around two-thirds that of the unmolded material
- “Stair-stepping” issue in the vertical build direction
What Is SLA?
Stereolithography was developed in the late 20th century and remains a prominent printing technology among experts today. SLA resin-based 3D printers employ photopolymerization, a laser-based technique, to solidify soluble resin into plastic.
SLA components have the greatest precision, resolution, detail clarity, and surface finish. Nonetheless, SLA’s primary advantage is its adaptability. Some manufacturers have developed revolutionary photopolymer resin compositions for SLA 3D printers with a broad spectrum of thermal, optical, and mechanical qualities that mirror industrial, engineering, and conventional thermoplastics.
SLA is an excellent alternative for incredibly detailed prototypes demanding smooth surfaces and tight tolerances, including patterns, molds, and functional components. This printing technology boasts various applications in different industries, including product design and engineering, model development, education, and dentistry.
Designing For SLA
While creating models for SLA printing, you must adhere to roughly identical guidelines for designing as those of an FDM printer. You should design the item to eliminate unnecessary support.
In SLA printing, unnecessary supports could come in ceilings, webs, gussets, or points. Layer thickness could be as low as 5 to 10 microns, resulting in translucent elements.
Pros
- Economical for limited production (1–20) items
- Moderately quick
- The layer thickness is between 5 and 15 microns, resulting in a superior surface polish
- You can paint the finished elements
Cons
- Costly materials
- Resin is harmful, but when combined with IPA, it becomes more hazardous
- You must secure and transport resin to a specialized firm for disposal
- Post-processing is not only necessary but also a messy, multithreaded operation
- The vertical build orientation produces the weakest prints
- Material waste isn’t recyclable and difficult to control
- Supports required
- Occasionally, the laser requires calibration
- Photopolymers are hazardous, like the fumes released throughout the manufacturing process
- The layer-thickness can vary between various resins
What Is SLS?
For industrial purposes, SLS is a prominent printing technology for the additive manufacturing process. Manufacturers and engineers depend on this technology to create high-quality, functional components.
SLS printers utilize a solid laser to bind tiny polymer powder particles together. Throughout printing, the unmelted powder acts as a support framework for the item, reducing the requirement for specialized support structures.
Therefore, SLS is suitable for fabricating intricate geometries, including those with negative elements, internal features, and undercuts. The mechanical qualities of SLS-printed products are superior, with strength equivalent to those of injection-fabricated elements.
SLS-manufactured components have a rough surface polish and almost no noticeable layer lines. The most widely used material for SLS printing is Nylon. This prominent engineering thermoplastic has outstanding mechanical qualities. Besides, Nylon is flexible and lightweight, resistant to Ultraviolet radiation, chemicals, water, dirt, shock, and heat.
The blend of cost reduction per element increased efficiency, and recognized materials render this printing technology popular amongst engineers. They use this technology in functional interfaces and sometimes as an alternative injection molding in bridge or special edition fabrication because it’s more affordable.
Designing For SLS
Designers select SLS over FDM and SLA due to its freedom of shape. It’s possible to create moveable components with intricate geometry. As there is no need for supporting structures, it’s also simpler to create intricate designs with thin walls and sharp edges.
This printing technology is extremely accurate, with a layer thickness between 0.06 mm and 0.15 mm. However, like with SLA and FDM, heterogeneity in material characteristics weakens the item in the vertical build plane.
Pros
- Durable prints
- No structural support is required
- Smooth surfaces make it difficult to distinguish the layer
- Movable components with intricate interior geometry
- Desktop SLS 3D printers are more affordable than industrial units
- Powder reusable following printing
- Material prices are low to modest while maximizing the workspace
- There’s no need for specialized labor
Cons
- Industrial machinery is costly
- Necessary to clean the machine when changing materials to prevent contamination
- Increased lead time
- Extended print time (for bigger objects)
- Pressurized air and a vacuum cleaner needed for powder management throughout post-processing
FDM vs SLS Vs SLA: Comparing Some Key Features & Considerations
Different 3D printing technologies have varying weaknesses, strengths, and needs and are appropriate for various industries and applications. The table below summarizes some significant considerations and features of SLS vs SLA and FDM.
FDM Vs SLS Vs SLA Printers: Comparing Rate Of Return (ROR) And Printing Expenses
Typically, you should select the 3D printing technology that sounds right for your organization. Over the decades, costs have decreased substantially, and currently, all three printing technologies are accessible in small, cost-effective systems.
The cost of 3D printing extends beyond initial equipment purchasing costs. Based on the printing technology and the required production level, labor and material expenditures considerably affect the price.
Here’s a comprehensive overview of SLS vs SLA and FDM 3D printing technologies.
Final Thoughts
Without a doubt, 3D printers are transforming the manufacturing landscape, thanks to their recent surge in popularity and advancements in technology. Nonetheless, your ideal printing technology will mostly rely on your intended outcome.
If you would like to generate a more cost-effective prototype that could withstand numerous tests, FDM printing is a perfect choice. On the other hand, if you want to create smaller, more detailed items that don’t demand finishing touches, SLA might be a better choice.
Although SLS is yet to become an individual printing alternative, it’s the preferred option for rapidly producing a small number of prototypes in various materials. Other vital considerations to take include safety, timeline, and budget.
3D printer applications are as diverse as the persons who utilize them. Hopefully, this guide assists you in understanding SLS vs SLA and narrowing down your hunt for the 3D printing technique that’s appropriate for your project.
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Scott Gabdullin
Scott Gabdullin is a Canadian entrepreneur, investor, and marketing expert who has successfully combined his passion for technology and innovation with a love for adventure and exploration.
Scott brings 12 years of digital marketing experience and a hardcore work ethic to his new passion for 3D printing. If he is not working on this business, he is likely travelling and Overlanding across North America with his wife and 2-year-old son in their Jeep Rubicon.
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