3D printing opens up exciting possibilities for rapid prototyping, hobby projects, and small manufacturing. The two most popular technologies for desktop 3D printing are fused deposition modeling (FDM) and resin printing. But when it comes to choosing a 3D printer, how do you decide between FDM vs resin?
Both methods have unique advantages and limitations. Getting clear on the key differences will help you select the best technology for your needs and skill level. This in-depth comparison examines crucial factors from print quality and speed to operating costs, safety, and ideal use cases.
How FDM and Resin 3D Printing Work
FDM printers build objects by heating and extruding thermoplastic filament material layer by layer using a moving print head. Each new layer fuses to the previous one as it cools and hardens.
Resin 3D printers utilize liquid photopolymer resin tanks and UV light to cure each layer. The UV exposure causes the resin to solidify in the exact pattern defined in the 3D model file.
There are a few types of resin printer technologies:
- Stereolithography (SLA): Uses a laser to tracing out each layer and selectively cure photopolymer resin
- Digital Light Processing (DLP): Projects a single image of each layer to flash-cure resin
- Liquid Crystal Display (LCD): Uses LCD screens and UV lights to cure each layer of resin
Both methods construct objects additively by building up material rather than traditional machining which removes material. But the technologies result in some significant differences.
Print Quality Comparison
When it comes to resolution and surface finish, resin printers deliver exceptional print quality and smoothness. High-end SLA printers can achieve layer resolutions around 0.01-0.05mm.
FDM printers are generally limited to 0.05-0.3mm layer heights. Even using the smallest layer height, the nature of extruded thermoplastic material still results in visible layers with a discernible grain.
The liquid resin cures into a homogeneous solid and doesn’t show individual layers once cured. This enables remarkably detailed prints. Resolution is only limited by the XY positioning system and laser or image projection system.
To demonstrate, a model of Rodin’s The Thinker was printed on a Formlabs Form 3 SLA printer at 0.025mm layer height and an Ultimaker S5 Pro FDM printer with a 0.6mm nozzle at 0.05mm layer height.
The resin print captures incredible detail down to wrinkles in the skin and fingernails. The FDM print loses some of that precision but maintains an accurate overall form. With the proper post-processing, FDM prints can achieve decent surface smoothness, but layer transitions remain slightly visible.
Speed Comparison
When it comes to printing speed, resin systems are much faster overall with build times up to 45x faster than FDM.
LCD and DLP resin printers that cure full layers in single exposures have a significant advantage over technologies that must trace out each layer such as FDM’s heated nozzle and SLA’s laser.
A 15cm cube can print in just over 2 hours on a DLP printer while taking approximately 90 hours on a typical FDM printer. Of course, print speeds can vary based on factors like layer height, infill percentage, and material used. But resin’s speed lead makes it the go-to for rapid prototyping needs.
Material Options
FDM printers offer the most filament type options. Common materials like PLA, PETG, ABS, TPU, nylon and composites give a wide range of mechanical properties. Color choices are nearly endless.
However, most resins utilize an acrylate photopolymer base. Variations in flexibility, durability, and heat/moisture resistance are achieved by additive modification.
While color options used to be limited, many resin manufacturers now offer pigmented resins in vivid hues. Specialty resins also provide translucent and transparent optical clarity unmatched by FDM thermoplastics.
Operating Cost Comparison
When evaluating the operating costs of FDM vs resin printing, there are some key considerations:
- Printer Cost – Entry-level FDM machines can be under $200 while resin printers start around $250. High-end industrial machines can cost tens of thousands.
- Material Costs – FDM filament runs around $20 per kg while resin is around $50-100 per liter. But FDM uses more material for larger builds and supports.
- Speed – The slower speed of FDM causes higher energy consumption over time.
- Maintenance – FDM printers require periodic calibration and replacement of consumables like nozzles. Resin printers have screens and optical components needing occasional replacement.
Overall, resin systems tend to have lower operating costs for small parts production. But large-volume functional prototyping favors the economy of FDM printing.
When factoring in printer and material costs over thousands of print hours, FDM has the lowest total expenses due to subsystem lifetimes and build speed.
Safety Considerations
Liquid resin requires handling precautions that FDM filament does not. Resin fumes contain volatile organic compounds that can cause skin and respiratory irritation during printing.
Prints must be cleaned and post-cured to convert resin from its liquid state into inert solid photopolymer. Isopropyl alcohol is commonly used for removing uncured resin. Proper disposal of used alcohol/resin solution is also essential.
Most manufacturers recommend operating resin printers in well-ventilated areas inside enclosures with extracted exhaust air vented outdoors. Nitrile gloves and eye protection should be worn when handling uncured prints and resin reservoirs.
FDM printers mainly generate particulates when printing higher-temperature materials like ABS. Generally, they can be operated indoors without additional ventilation.
Ease of Use Comparison
For first-time users, FDM 3D printers offer the most beginner-friendly experience. Limited setup and infrequent calibration make it easy to start printing quickly. Changing filament or removing finished prints take just a few clicks.
Resin printing involves more pre-print preparation with tank filling, build plate leveling, and screen calibration. Parts need alcohol washing and curing afterwards. The process demands greater attention to detail and safety considerations.
While resin does present a steeper learning curve, LCD and DLP printers have become much more user-friendly in recent years. Many now include automated screen calibration and resin mixing/recycling functions.
Ideal Applications
FDM Printing
FDM printing suits applications like:
- Engineering prototypes
- Manufacturing jigs, fixtures, tools
- Educational models
- Architectural concept models
- Geometric sculptures
- Cosplay armor & props
- Repair parts
- Custom enclosures & housings
- Creative decorative builds
The ability to print large parts makes it ideal for structural items and functional prototyping. Having tangible test models early in design processes provides valuable insight for refining products going into production.
Affordable desktop FDM printers give small businesses, entrepreneurs, and design firms rapid concept realization and custom tooling capabilities.
Resin Printing
Resin printing excels at applications requiring intricate details and smooth surface finish like:
- Precision industrial prototypes
- Automotive design models
- Aerospace turbomachinery
- Medical devices
- High jewelry master patterns
- Dental restorations like clear orthodontic aligners
- Tabletop miniatures & game assets
- Scale architectural modeling
- Articulated toys & action figures
- Collectible statues & sculpture
- Production parts under 5 inches
The high accuracy, precision, edge quality, and surface smoothness perfectly suit visual design models requiring crisp details. Jewelry prototyping takes advantage of resin’s ability to print tiny features.
Resin’s dimensional stability also makes it ideal for masters used in the moldmaking and casting processes for short-run manufacturing.
The smooth surface saves extensive sanding and filling steps before making molds. This enables small businesses to cost-effectively produce custom consumer products.
Which One Is Better for You?
When deciding between FDM vs resin 3D printing, consider what applications you’ll use it for and your experience level.
FDM suits beginners due to lower costs and easier operation. The ability to print functional prototypes in higher-temperature engineering materials like ABS make it ideal for automotive, aerospace, and industrial use.
For designers and artists seeking ultra-fine details and surface quality, resin delivers exceptional resolution and smoothness. The variety of specialty resins allow properties from simulated injection molded plastics to castable waxes and resins.
Many users operate both FDM and resin printers to take advantage of each technology’s unique strengths. Using FDM for large tools or structural items paired with a resin printer for detailed precision fixtures combines affordability and accuracy.
Getting competent with modeling, support strategies, slicing basics, and post-processing workflows transfers between both methods. So once familiar with desktop 3D printing fundamentals, transitioning to a new printer type becomes much simpler.
Wrapping Up
From instant design validation to custom product manufacturing, both FDM and resin printing empower innovative problem solving and creativity.
Getting to know the core characteristics of each technology equips you to select the best type and build method to bring your projects to life. Matching use case requirements to printer capabilities and design intent is key.
FDM provides extreme size flexibility plus approachable operation while resin excels at intricate precision and surface perfection. Together they make a complete 3D printing solution.
Choosing between FDM and resin ultimately comes down to the parts you need to create, skill level, and budget. Hopefully this detailed comparison gave useful decision-making insight. Let us know if you have any other questions in the comments!
