Light curing (including SLA and DLP) and FDM (Fused Deposition Modeling) are two of the most popular 3D printing technologies, but they excel in entirely different scenarios. Calling one “better” universally is inaccurate—their value depends on your project’s precision needs, budget, material requirements, and application. This article compares their core traits, performance, and use cases to help you pick the right technology.
1. Core Principles & Key Differences (Side-by-Side Table)
The first step to choosing is understanding how each technology works. Below is a breakdown of their fundamental differences:
| Aspect | Light Curing (SLA/DLP) | FDM (Fused Deposition Modeling) |
| Technology Type | Photopolymer-based 3D printing | Thermoplastic-based 3D printing |
| Core Principle | Uses ultraviolet (UV) light to cure liquid photosensitive resin layer by layer into solid shapes. | Melts thermoplastic filaments (e.g., PLA, ABS) via a heated nozzle, then extrudes and stacks the material layer by layer. |
| Key Components | Resin tank, UV light source (laser for SLA, projector for DLP), build platform | Filament spool, heated nozzle (180–260°C), heated bed, build platform |
| Support Structure | Requires removable support structures (for overhangs/hollows) – post-processing needed to remove. | May need supports (for steep overhangs) but often uses less support material than light curing. |
2. Critical Performance Metrics (Detailed Comparison)
To evaluate which fits your project, compare their performance across key metrics:
| Metric | Light Curing (SLA/DLP) | FDM (Fused Deposition Modeling) |
| Precision & Detail | Excellent – Layer thickness as low as 0.025mm (SLA); produces smooth surfaces with fine details (e.g., tiny engravings, thin walls). Ideal for intricate models like jewelry or dental crowns. | Moderate – Layer thickness usually 0.1mm–0.3mm; visible layer lines on the surface. Complex details (e.g., small holes, thin features) may delaminate or collapse. |
| Material Options | Limited to photosensitive resins (e.g., general-purpose, transparent, high-temperature resistant, flexible). Resins are specialized and costly. | Wide range of thermoplastics (e.g., PLA, ABS, PETG, TPU). Materials are affordable, easy to store, and widely available. |
| Printing Speed | Fast for small models – Single layers cure in seconds (DLP is faster than SLA). Large models may need layer stitching, which adds time. | Slow – Even small parts take 3–8 hours; large models (e.g., a 30cm tall prototype) can take 24+ hours. Speed drops further for high-precision prints. |
| Post-Processing | Complex – Requires: 1. Rinsing with alcohol to remove uncured resin; 2. Secondary UV curing to harden parts; 3. Sanding/polishing to remove support marks. | Simple – Minimal processing needed. May require: 1. Trimming support material; 2. Light sanding to smooth layer lines (optional). |
| Cost | High – Printers cost \(1,000–\)10,000+ (DLP is pricier than SLA); resin costs \(50–\)200 per liter. Maintenance (resin tank cleaning, filter replacement) adds expense. | Low – Entry-level printers cost \(200–\)800 (e.g., Creality Ender series); filaments cost \(20–\)50 per kg. Maintenance is simple (nozzle cleaning, bed leveling). |
| Mechanical Strength | Moderate to high – Engineering resins (e.g., tough resin) match the strength of injection-molded parts. Standard resins are brittle. | Moderate – PLA is rigid but brittle; ABS/PETG offer better impact resistance. Parts have good layer adhesion but lower strength than metal. |
3. Ideal Application Scenarios
Use this guide to match each technology to your project goals:
3.1 When to Choose Light Curing (SLA/DLP)
- High-Precision, Intricate Parts: Projects needing fine details or smooth surfaces, such as:
- Jewelry prototypes (tiny engravings, complex patterns).
- Dental models (accurate tooth shapes for crowns/bridges).
- Transparent/translucent parts (e.g., light covers, lens prototypes).
- Aesthetic Prototypes: Products where appearance matters (e.g., consumer electronics casings, toy designs).
- Small-Scale Production: Low-volume runs of detailed parts (no need for mass manufacturing molds).
3.2 When to Choose FDM
- Functional Prototypes: Parts needing basic strength, such as:
- Mechanical components (gears, brackets, hinges).
- Educational models (e.g., 3D anatomy models for schools).
- Maker projects (e.g., custom phone stands, 3D-printed tools).
- Large-Size Models: Projects too big for light curing printers (e.g., architectural models, furniture prototypes).
- Budget-Conscious Projects: Hobbyists, students, or startups with limited funds (low printer and material costs).
4. Safety & Operation Considerations
Safety is often overlooked but critical for long-term use:
| Aspect | Light Curing (SLA/DLP) | FDM (Fused Deposition Modeling) |
| Safety Risks | – Uncured resin is toxic and irritant (avoid skin/eye contact). – Resin fumes require ventilation (use a fume hood or open windows). – UV light can damage eyes (wear protective goggles). | – Heated nozzle (200–260°C) risks burns (keep hands away). – ABS printing releases harmful fumes (needs ventilation). – PLA is non-toxic (safe for home use). |
| Ease of Operation | Moderate – Resin handling requires care; platform leveling is less critical than FDM. | Easy for beginners – Simple setup (load filament, level bed); most printers have user-friendly software. Common issues (e.g., layer adhesion) are easy to troubleshoot. |
5. Yigu Technology’s Perspective
At Yigu Technology, we believe the choice between light curing and FDM hinges on balancing precision, cost, and functionality. For clients needing high-detail prototypes (e.g., dental labs, jewelry designers), light curing (especially DLP) delivers unmatched accuracy. For functional parts or budget-friendly projects (e.g., startup prototypes, educational models), FDM is the practical choice. We often recommend combining both: Use FDM for large structural components, then light curing for small, detailed parts that attach to them. Our advice? Start by defining your non-negotiables—if “surface smoothness” or “detail” is top priority, light curing wins; if “cost” or “size” matters most, FDM is better.
6. FAQ (Frequently Asked Questions)
- Q: Can light curing 3D printers use FDM materials (e.g., PLA)?
A: No. Light curing printers only work with photosensitive resin (they rely on UV light to cure liquid resin, not heat to melt filaments). FDM materials are incompatible.
- Q: Is FDM suitable for making parts that need to withstand high temperatures?
A: It depends on the material. Standard PLA melts at ~60°C (not heat-resistant), but ABS (melts at ~100°C) or PEI (melts at ~210°C) can handle moderate heat. For high-temperature needs (e.g., engine parts), light curing with high-temperature resin is better.
- Q: Which technology is better for beginners?
A: FDM is ideal for beginners. It has lower upfront costs, simpler operation (minimal safety risks with PLA), and easier troubleshooting. Light curing requires careful resin handling and more complex post-processing—better for users with some 3D printing experience.