3D printing technology has advanced tremendously since its inception over 30 years ago, offering rapid prototyping capabilities to industries and unlocking creativity for hobbyists and makers. The two most popular desktop 3D printing technologies today are:
FDM (Fused Deposition Modeling): Filament is melted and deposited layer by layer to build objects.
Resin 3D Printing: Liquid photopolymer resin is cured by light to build objects layer by layer.
But which one is better for your specific application? This guide provides a detailed comparison of FDM vs resin 3D printing across key factors to help you decide.
A Brief History of FDM and Resin 3D Printing
FDM 3D printing traces its origins back to the 1980s when Scott Crump patented the technology of building objects by depositing melted plastic filament. The first commercial FDM 3D printer called the SLA-250 was sold in 1990 by Stratasys, Crump‘s company.
The technology refined over the 1990s and became more accessible for broader use, culminating in patents expiring in 2009 that opened the doors for affordable desktop FDM printers to enter the mainstream consumer market.
Stereolithography (SLA), the precursor to modern resin 3D printing was invented back in 1986 by Chuck Hull – the founder of 3D Systems. This first technique used an ultraviolet laser to selectively cure photopolymer resin layer by layer to build an object.
Through the 1990s, SLA printers became faster and more accurate, but the high costs limited adoption outside of industrial prototyping. The expiration of key SLA patents in early 2010s allowed lower-cost resin printers based on DLP and LCD technologies to emerge, targeted at professionals, small businesses and hobbyists.
So while both technologies have been around for 30+ years, only this past decade brought them within economic reach of wider audiences beyond deep-pocketed industries.
How Do FDM and Resin Printers Work?
While both build objects layer by layer from digital 3D model files, FDM and resin printers have vastly different underlying mechanisms.
FDM Printers
FDM printers work by heating and melting plastic filament that is fed through a heated print nozzle. This nozzle deposits the melted filament tracing out the model one layer at a time on a build plate. Once a layer is complete, the build plate lowers and the next layer is deposited.
More advanced FDM printers may have dual nozzles for printing using dissolvable supports or in multiple colors. The most common filament materials are PLA and ABS plastic.
FDM printing works by melting and precisely depositing thermoplastic filament
Resin Printers
In resin-based 3D printers, models are built from liquid photopolymer resin that hardens when exposed to light. The resin vat is located under a transparent bottom layer through which solidifying light shines in specific patterns matching each layer of the 3D model.
For LCD printers, this bottom layer is a LCD panel displaying a sequence of images that define each model layer. In DLP printers, light from a digital projector below is shined through a light filter onto the build plate via a process called digital light processing.
Once a layer is cured, the build plate lifts allowing fresh resin to flow beneath in preparation for projecting the next layer image or pattern.
Common resin materials include standard, durable, flexible and dental types of photopolymer resin. Some printers also support castable or moldable resins.
Resin printers selectively cure liquid resin layer-by-layer using light patterns from a LCD panel or projector
Print Quality – FDM vs Resin
When it comes to print quality, resin 3D printers deliver far superior accuracy, tolerances, detail resolution and smoothness over FDM prints.
Typical resin printers have XY resolution of 0.05mm vs 0.1-0.4mm for FDM. They produce extremely sharp edges with no visible layer lines along the sides of prints. This lets resin printers create highly detailed miniatures, jewelry pieces or precision industrial prototypes not possible on FDM.
However, getting this level of polish and detail needs proper calibration, model orientation decisions plus post-print cleanup and curing. Out of the printer, resin models have a sticky surface with uncured resin needing removal by washing and further final curing under UV light.
FDM printers have lower print resolution than resin models, only hiding visible layer lines on models with very gradual curves. Getting dimensionally accurate FDM prints needs properly calibrated steps, tight filament and nozzle temperatures plus optimal print speeds.
When dialed in, though, FDM prints are ready to use off the print bed. At most some light sanding, painting or acetone finishing may be required if aiming for smooth sides or glossy finishes.
Resin based printing (left) offers vastly sharper detail & accuracy while FDM (right) excels at larger models
Speed and Build Volume
In terms of pure print speed, resin printers significantly outpace FDM technology – with build speeds ranging from 1.5-7 cm per hour. This compares very favorably to the 1-2 cm per hour range for most filament printers.
However, FDM printers have much larger average build volumes – ranging from ~15-30 cm cubes for desktop machines while resin printers max out at ~20 cm length or width. This allows FDM to economically produce much larger prints.
Considering size limitations, resin-based printing lends itself perfectly to detailed miniatures, jewelry, dentures and engineering prototypes with build areas typically under 250 x 160 x 200 mm.
For more substantial objects like tools, machine components, larger scale cosplay armor and helmets – FDM‘s higher build volumes reaching up to 400 x 400 x 500 mm offer clear advantages.
FDM printers (right) have much bigger build volumes than desktop resin printers (left)
Materials and Applications
One of FDM printing‘s biggest strengths lies in the broad material choice available to users. Dozens of filament varieties spanning plastics like PLA, ABS, PETG to composites like carbon fiber, metal-filled and wood allow printing functional, durable parts.
Specialty filaments also enable exotic aesthetics from glow-in-the-dark to color changing. Supportive communities have further pushed multi-material printing using dissolvable filaments.
For resin 3D printers, material options are currently quite limited relative to FDM but the varieties are expanding rapidly. Base resins are usually either rigid or flexible with specialty resins enabling casting, dental and biocompatible prints.
Industrial applicability also diverges between the technologies – FDM prints mechanical tools, machine components, functional prototypes for field testing where durability and environmental resilience matter.
Resin handles artwork, miniatures, fine featured molds and modeling plus medical and dental devices where control over microscopic dimensions and surface finish take priority.
For home 3D printing hobbyists, both present excellent value and capabilities – FDM suits those who wish to make household items, cosplay props, toys and customizable products. Resin printing appeals to tabletop gamers and enthusiasts looking for ultra-detailed prints.
FDM (left) excels at durable functional parts like machine components while resin (right) is perfect for detailed miniatures
Operating Costs and Environmental Impact
When accounting for material consumption over time, FDM filaments cost 2-3 times lower than liquid resin per print volume. But the lower print speeds significantly raise energy usage – balancing out this advantage.
Recent lifecycle assessments show both technologies have similar carbon footprints – with FDM printers consuming over 3 times the electricity of resin printers. But resin material emissions offset this during production.
Proper containment, handling and disposal of liquid resin is also crucial considering its toxicity and risk of environmental contamination. Users should prevent resin contact with skin and provide adequate room ventilation plus wear gloves and eye protection.
While melted plastic also releases emissions, FDM filaments don‘t pose nearly the same health or spill hazards for operators and communities which contributes to their popularity among hobbyists.
Ease of Use and Learning Curve
For complete beginners to 3D printing, FDM offers a much gentler onboarding curve over the involved post-processing and safety factors using resin printers.
FDM printers have open material loading, intuitive controls and visible build areas keeping users engaged. Build platforms don‘t require leveling between prints and finished objects lift off the plates with far less force compared to tacky resin prints.
Without the need for solvent washing, special curing stations and containment around resin‘s toxicity – the simpler end-to-end FDM print workflow enables faster mastery for hobbyists.
But for experienced makers seeking ultra-detailed results, resin certainly delivers superior surface finishes that justify its steeper orientation and dial in process.
Cost Comparisons – Printer Hardware, Materials, Maintenance
When evaluating the system costs, resin and FDM desktop setups with comparable community support and reliability in the $300-600 range provide starting points appealing to home and school users.
High quality 1 kg filament spools cost around $20-30 depending on materials allowing dozens of medium sized prints. Resin liter bottles start at $50-100 for sufficient specialty resin for 10-30 detailed prints before refills.
Long-term costs balance out depending on use cases – FDM suits printing larger household items, mechanical prototypes and presonalized merchandise. For miniatures and jewelry, resin offers an economical alternative to purchasing expensive painted pieces.
Over 5 years, the costs of mid-range machines likely reach parity taking into account replacement filters, UV bulbs, FEP film for resin printers and occasional nozzle or hotend upgrades for FDM.
Recent Innovations Expanding Capabilities
Both FDM filament and resin formulations have been expanding to allow mimicking properties from tough, flexible and heat resistant to castable and biocompatible.
FDM printers are also gaining multi-tool capabilities allowing printing using dissolvable supports and dual extrusion for multi-material objects. Meanwhile, LCD panel and light source developments may expand resin printer build sizes upwards over the next few years.
Integrated post-processing stations for washing and curing finished resin pieces are emerging as well – helping increase ease of use. And with increased speed, accuracy and parametric controls – desktop systems inch closer to industrial grade production quality.
Summary: Key Factors Favoring FDM vs Resin Printers
FDM Printers
- Lower material costs for larger prints
- Larger build volumes up to 8-10 times resin printers
- Broad material versatility from PLA, PETG, ABS, composites
- Easier to start out for complete beginners
- Suitable for larger functional prints like tooling and prototypes
Resin Printers
- Far superior detail, resolution down to 25 microns (0.025 mm)
- Smooth surfaces with no layer lines
- Great for miniatures, jewelry, art pieces
- Ideal for dental, medical applications
- Up to 5 times faster print speeds than FDM
Conclusion
For most hobbyists and casual makers starting out, FDM printers offer the easiest path with a wealth of community expertise around maintainable machines having quite reliable out of box performance for the money.
The capacity to economically produce functional and customizable objects offers general appeal – though reaching professional surface quality requires dialing in many parameters.
As needs evolve, upgrading machines or switching to resin can provide detailed results. Resin printers target users seeking beautiful high-precision prints unmatched by FDM capabilities.
The ideal combination? Perhaps starting with an easy-to-use FDM machine supplemented by a high-resolution resin printer for jewelry-class prints makes sense for many – playing into each technologies‘ unique strengths.
Hopefully this deep dive dispels any misconceptions around these truly differentiated yet complementary approaches that both have valuable roles enabling digital manufacturing. Understanding where they excel and fall short allows matching startups, businesses and individuals with the 3D printing technology suited for their specific applications.
