Stereolithography (SLA) and FDM are two of the most common options, but picking the right one isn’t always clear. Each has different strengths, costs, and best-fit uses. In this post, we’ll help you quickly sort out the differences, so you can make a smarter decision and move forward with confidence.
SLA gives you higher detail, smoother finishes, and is best for small, precise parts. FDM is cheaper, faster, and better for simple or larger designs. Your ideal choice depends on your part’s use, required detail, and budget. If accuracy and finish matter most, go with SLA. If strength, size, or cost matters more, FDM usually wins.
FDM and SLA might look similar from the outside, but they work very differently. The next sections explain how each one works, where they shine, and what you should consider before choosing.
Technology Overview
SLA and FDM use different ways to build 3D parts. One uses liquid resin. The other uses melted plastic. Understanding how they work will help you pick the right one.
How SLA Works？
SLA stands for Stereolithography. It uses a laser to harden liquid resin. The resin sits in a tank. A UV laser shines into the resin and cures it layer by layer.
Each layer sticks to the one before it. The part lifts from the tank as it forms. This process creates very smooth surfaces and sharp details. SLA works well for small, precise parts that need a clean finish.
How FDM Works？
FDM stands for Fused Deposition Modeling. It uses a heated nozzle to melt plastic filament. The nozzle moves along a set path and lays down the plastic layer by layer.
The material cools and hardens right away. Then the printer builds the next layer on top. FDM is a simpler method. It’s faster and costs less to run. This makes it good for quick prototypes or large, basic shapes.
Core Differences Between SLA and FDM
SLA uses liquid resin. FDM uses solid filament. SLA needs a laser and curing process. FDM melts and extrudes plastic through a nozzle.
SLA creates smoother, more detailed parts. FDM produces stronger parts but with rougher surfaces. SLA needs post-curing. FDM needs less finishing. SLA costs more. FDM is usually more budget-friendly.
Użyte materiały
The type of material each method uses affects strength, flexibility, finish, and cost. It also impacts supply and delivery, especially for custom or large-volume projects.
SLA-Compatible Resins
SLA printers use liquid photopolymer resins. These resins harden under UV light. There are different types for different needs. Some are rigid, others flexible—some mimic ABS or rubber.
The finish is usually smooth. Resins can offer high detail, but they tend to be brittle. They are also sensitive to heat and UV over time. Shelf life and storage need extra care.
FDM-Compatible Thermoplastics
FDM uses solid thermoplastic filament. These are common plastics like PLA, ABS, PETG, and Nylon. Many are the same types used in injection molding.
They’re strong, affordable, and widely available. Some are flexible, others are heat- or chemical-resistant. You can even get specialty blends, like carbon fiber or wood-filled filaments.
Material Availability and Supply Chain Considerations
FDM filaments are easier to source. You can find them in many places, from industrial suppliers to local stores. There are more brands and grades to choose from.
SLA resins are more limited. They often come from specific manufacturers. Shipping resin can take longer, and it needs careful handling. This affects both lead times and long-term sourcing plans.
Printing Accuracy and Resolution
Accuracy and surface finish are key when you’re printing parts that need to fit, look good, or perform in tight spaces. This is where SLA and FDM show clear differences.
Layer Thickness and Detail
SLA printers can produce layers as thin as 25 microns. This allows for very fine detail and smooth curves. You can print small text, sharp edges, and intricate features.
FDM usually prints layers between 100–300 microns. You get visible layer lines. Fine details might blur or round off. It’s harder to achieve sharp corners or thin walls.
Surface Finish Comparison
SLA parts come out smooth. The cured resin has a polished look. Even straight from the printer, the part looks clean. Post-curing makes it even better.
FDM parts show clear layer lines. The surface often feels rough. You may need sanding or coating to improve the finish, especially for show parts or customer-facing models.
Dimensional Accuracy in Complex Parts
SLA is better for parts with complex features, tight fits, or fine holes. The resin holds shape well during curing. You can expect good repeatability.
FDM can warp, especially with larger parts or enclosed shapes. Corners may lift. Fine holes might not print clean. Shrinkage and material flow can reduce precision.
Build Volume and Size Capabilities
The size of your part affects which method works better. If you’re printing something big, the build volume becomes a major factor.
Typical Print Sizes for SLA
SLA printers usually have smaller build volumes. Desktop models handle parts around 145 × 145 × 175 mm. Large-format SLA machines exist, but they are costly and less common.
SLA works best for small, high-detail parts. If you need larger pieces, you should split the model into sections.
Typical Print Sizes for FDM
FDM printers often have much larger build volumes. Standard desktop machines can print up to 300 × 300 × 400 mm. Industrial models can go far beyond that.
This makes FDM a better fit for large prototypy, obudowy, and structural parts. You can print full-size models in one go, saving time and effort.
Scaling for Prototyping vs. Production
FDM scales well for big prototypes and early-stage testing. You can print fast and cheap to check the form and fit.
SLA is better for small production runs that need fine detail. It’s often used for master patterns, molds, or short-run custom parts where looks and accuracy matter most.
Szybkość i wydajność
Print speed isn’t just about how fast a machine moves. You also need to look at prep time, cleanup, and how easily you can scale.
Print Speed Differences
FDM is usually faster for basic shapes and large parts. It lays down thick layers and moves quickly. You can adjust speed and layer height to save time.
SLA prints more slowly. The laser traces each layer precisely. The finer the detail, the longer it takes. Small parts with tight tolerances take the most time.
Print Preparation and Post-Processing Time
FDM setup is simple. Load filament, level the bed, and hit print. Post-processing is quick too—remove supports and maybe sand the surface.
SLA needs more prep. You must handle resin carefully. After printing, parts need to be rinsed, cured under UV, and cleaned. It takes more time and tools.
Batch Production Considerations
FDM is good for printing multiple parts at once, especially if they’re simple. You can fill the whole build plate and run jobs back to back.
SLA is slower in batches. You must leave space between parts for resin flow. Post-processing also gets longer with more parts. Still, SLA batches work well when you need consistent detail and smooth finishes.
SLA vs FDM：Surface Finish and Aesthetics
When your part needs to look clean and professional, whether for display, customer demo, or end-use, surface quality becomes a key factor.
Visual Smoothness of SLA
SLA delivers a smooth, glossy surface right off the printer. Even curved or complex shapes look refined. There’s little to no visible layering.
This makes SLA a good fit for models, molds, and visual prototypes. It’s often used when the part needs to be painted or shown to clients.
Layer Lines in FDM
FDM shows visible layer lines. The surface feels rougher and shows each pass of the nozzle.
You can reduce the effect with fine layer settings, but it still won’t match SLA. Post-processing, like sanding or vapor smoothing, is often needed to improve appearance.
When Appearance Matters Most？
Use SLA when looks are a priority. It’s best for presentation pieces, small, detailed parts, and anything that needs a polerowane wykończenie without extra work.
FDM works fine for internal parts, early tests, or functional items where surface roughness doesn’t matter. If you’re short on time or budget, it’s the quicker option.
Wytrzymałość i trwałość
When your part needs to handle stress, pressure, or long-term use, mechanical strength becomes more important than looks or fine detail.
Tensile Strength of FDM Parts
FDM parts are generally stronger. Materials like ABS, PETG, or Nylon offer good tensile strength. They can handle stress, bending, and impact better than most resins.
The strength depends on print settings, layer bonding, and material type. For functional parts, nawiasy, or housings, FDM is often the better choice.
Brittle vs. Tough Nature of SLA Parts
SLA parts are more brittle. Even though resins can crack under pressure, they may snap if dropped or stressed.
While SLA parts are accurate and smooth, they aren’t built to flex or take impact. Some specialty resins offer better toughness, but they still lag behind FDM thermoplastics.
Long-Term Stability and Use Cases
FDM parts last longer in real-world use. They resist heat, UV, and wear better than SLA parts. They hold shape over time and work well in mechanical setups.
SLA parts may yellow, warp, or become brittle with age. They’re better for short-term use, cosmetic models, or parts that won’t face stress or outdoor use.
Porównanie kosztów
Cost affects every decision, especially when you’re working with tight budgets or testing new ideas. Here’s how SLA and FDM stack up in terms of total expense.
Equipment Investment
FDM printers are more affordable. You can get a good desktop unit at a low cost. Even industrial models cost less than large SLA machines.
SLA printers cost more, especially if you need a large build volume or a higher power laser. The upfront price is higher, and accessories for washing and curing add to it.
Material Pricing
FDM filaments are cheaper. Common types like PLA or ABS are widely available and cost less per spool. Even specialty blends stay affordable for most shops.
SLA resin is more expensive per liter. Some types cost several times more than filament. You also waste more resin during use, especially for larger prints or multiple runs.
Operating and Maintenance Costs
FDM is easy to run and maintain. Nozzles may clog, and beds need leveling, but parts are cheap and easy to replace. Power use stays low.
SLA requires more care. Resin tanks and build plates need frequent cleaning. You’ll need gloves, alcohol, curing stations, and disposal containers. Over time, these extras raise running costs.
SLA vs FDM Quick Comparison: Key Differences at a Glance
A side-by-side comparison of SLA vs FDM covering cost, quality, speed, and materials—perfect for fast decision-making in 3D printing.
| Funkcja | SLA | FDM |
|---|---|---|
| Printing Method | Laser cures liquid resin | Melted filament extruded through nozzle |
| Typ materiału | Photopolymer resin | Thermoplastic filament (PLA, ABS, etc.) |
| Detail Level | Bardzo wysoko | Umiarkowany |
| Wykończenie powierzchni | Smooth, clean | Visible layer lines |
| Wytrzymałość | Brittle but precise | Stronger and more durable |
| Build Volume | Mniejszy | Typically larger |
| Print Speed | Slower for detailed parts | Faster for large/simple parts |
| Setup & Cleanup | More complex (resin handling, curing) | Simpler setup and cleanup |
| Przetwarzanie końcowe | Rinsing, UV curing | Minimal (support removal, sanding) |
| Material Cost | Wyższy | Niżej |
| Koszt wyposarzenia | Wyższy | Niżej |
| Najlepsze przypadki użycia | Models, fine prototypes, visual parts | Functional parts, fast prototyping, large models |
| Konserwacja | More tools and steps | Easier and cheaper |
| Scalability (Batch) | Slower due to post-processing | Faster and more efficient |
| Heat & UV Resistance | Słaby | Better (depends on material) |
| Dokładność wymiarowa | Bardzo wysoko | Good, but may warp with size |
Decision-Making Guide
Choosing between SLA and FDM depends on what you need from your part. Look at the use case, your budget, and the material features that matter most to your project.
Based on Application Needs
Choose SLA for parts that need fine detail, smooth surfaces, or visual appeal. It’s great for dental models, small prototypes, or fit-check parts.
Pick FDM for parts that need strength, durability, or size. It’s better for brackets, fixtures, housings, or anything tested under stress.
Based on Budget and Resources
If you want low-cost prints, minimal cleanup, and easy setup, go with FDM. It fits small shops, fast prototyping, or early-stage testing.
If you have more budget, can handle post-processing, and need a refined look, SLA makes sense. It fits well in design studios or for client-ready models.
Based on Desired Material Properties
Use FDM when you need parts that flex, bend, or hold up to heat and wear. Thermoplastics offer better toughness and chemical resistance.
Use SLA when your part must be precise, clean, and stable in small features. Resins give better accuracy but won’t last under stress.
Wnioski
SLA and FDM serve different needs in drukowanie 3d. SLA gives you higher detail and smoother finishes. It’s best for small, precise, and good-looking parts. FDM is faster, more cost-effective, and better for strong, functional components. Your choice depends on the part’s use, size, finish, and how much you’re ready to spend.
Need help choosing the right printing method for your next project? Skontaktuj się z nami to get expert advice and fast solutions tailored to your design needs.
Hej, jestem Kevin Lee
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Kevin Lee
Mam ponad dziesięcioletnie doświadczenie zawodowe w produkcji blach, specjalizując się w cięciu laserowym, gięciu, spawaniu i technikach obróbki powierzchni. Jako dyrektor techniczny w Shengen, jestem zaangażowany w rozwiązywanie złożonych wyzwań produkcyjnych i napędzanie innowacji i jakości w każdym projekcie.
