FDM vs. SLA - Comparison of FDM and SLA 3D Printing | Fusion3

3D PRINTING TECHNOLOGIES COMPARED:
FDM vs. SLA

The two most popular 3D printing methods available right now are Fused Deposition Modeling, or FDM, and Stereolithography Apparatus, or SLA. The two technologies are dramatically different and each having unique benefits and drawbacks in terms of speed, durability, part quality, material cost, and use cases. Learn more about these two types of 3D printing technologies, and find the 3D printer that is right for you and your demanding application

Fusion3 F410
High Quality FDM 3D Printing

Fast, Reliable 3D Printers Made in the USA

SLA vs. FDM: THE PRINTING PROCESSES

FDM has become the most common 3D printing technology today. Invented over 30 years ago, this process works by heating a thermoplastic polymer and extruding it through a heated nozzle onto a flat surface. The nozzle traces a path to form a layer and once completed the bed is lowered or the nozzle is raised (depending on the type of printer) and the process is repeated to build your part to completion). FDM is an affordable and cost-effective way to build plastic parts without injection molding and depending on the 3D printer, deployed for end-use applications.
SLA uses a vat of resin that is light sensitive (photopolymer curable). A build plate is lowered into this vat and exposed to a UV laser which draws a pattern layer by layer against the plate, curing the resin forming the object. As each layer cures, the build plate is raised, allowing the next layer to be formed. The part is completed when all the payers is completed. The part is still susceptible to light and must be cured and allowed to fully harden.

SLA VS. FDM: MATERIAL COST

FDM 3D printers can print a wide range of different thermoplastic polymers as well as different composites. Generic materials such as ABS, PLA, PETG from quality suppliers can cost as low as $25 per kilogram. Branded, Engineering-grade materials such as Nylons, Co-Polyesters, Polycarbonate and various composites such as Carbon Fiber, Fiberglass and Kevlar may cost anywhere from $45 to $120 per kilogram. Lastly, exotic materials with unique, patented formulations and capabilities may cost anywhere from $60 per kilogram to over $500 per kilogram.
SLA 3D printers have a very limited selection of materials to print with. The photosensitive resins used are costly and tend to be proprietary to each manufacturer. One liter of resin costs approximately $100 to $200 depending on type and quality. There are 3rd party manufacturers who are selling less expensive resins, however, when we get to the safety aspects of resins later in this article, great care should be exercised when purchasing from these sources due to potential adverse health effects.

SLA VS. FDM: MATERIAL COLOR CHOICES

The wide variety of materials for FDM 3D printers is matched generally by the color selection. Engineering grade materials tend to have fewer color choices, only as those customers are less particular, however, companies that extrude filament have the ability to produce a wide variety of colors to meet market needs and can even produce custom colors for a customer.
The materials in the SLA universe however, do t have as wide a variety of colors and generally found in black, gray and transparent / translucent colors. SLA materials are blended from the original base material. For those with an experimental bent, you can attempt to mix in your own pigments to attempt to create your own colors. As previously mention, this should be done with care as this is both a difficult process and caution should be taken due to the health concerns of resins.

SLA VS. FDM: SURFACE FINISH

Since FDM is a process that applies the thermoplastic in layers, the outer surface of the part will show layer lines at varying amounts depending on the size of the layers and the type of feature. The layer thickness for many FDM 3D printers can range from 100 to 400 microns. The Fusion F410’s layer thickness with the .4MM print head can range from anywhere from 100 microns to 300 microns using our standard settings within the REACTOR software and can go as low as 20-50 microns if you were to create your own custom settings.
SLA 3D printers use a laser for drawing each line of the part and as a result each layer can be render with much finer detail and provide a smoother surface finish. Generally, an SLA part will be rendered at 20-60 microns.

SLA VS. FDM: PART ACCURACY

A general rule of thumb is that a professional / commercial FDM 3D printer will have excellent dimensional accuracy the larger the feature (click here for more information on how to choose the right 3D printer…). For smaller features, the dimensional accuracy will depend on a variety of factors including: the accuracy of that 3D printer’s motion control system, the material used, the settings used, and the design of the feature being printed.
SLA printers are intended to reach very fine resolutions for smaller parts and the dimensional accuracy is some of the best of the available 3D printing technologies on the market today.

SLA VS. FDM: PART STRENGTH & DURABILITY

FDM 3D printers draw from the established universe of commercially available thermoplastics that have been in use for decades. While a few materials such as PVC, Delryn, and others have not made their way to 3D printing, most are available as easily printed filaments. Also a wide variety of unique and interesting composites such as carbon fiber, fiberglass, Kevlar are now available and manufacturers continue to innovate with unique combinations and features such as ESD safe materials that attract new entrants to 3D printing each month, expanding the addressable market.

SLA 3D printers have made recent in roads in the development of stronger resins that when cured can mimic the qualities of known thermoplastics used in injection molding applications. However, they are fare from perfect and have yet to be proven in daily use in comparison to their established known polymers and composites from the molding and FDM universe. Generally, the SLA world is still hampered by the lack of durability and fragility from cured resin parts that break down over time from exposure to light and tend to be brittle.

 

SLA VS. FDM: EASE OF USE & SAFETY

FDM 3D printers are generally easy to use. The set up of the 3D printer is quite easy. You load a spool of filament into the extruder, prepare the print bed, load the file and away you go. The process is relatively simple and clean. The parts are dry and clean and usually you will only need to break off support structures from the areas that require (link to breakaway page). The remaining filament just needs to be stored in a sealed container afterwards.
Once an SLA print is completed, there is additional work to be done before you can handle the part. The part itself is messy and sticky. The remaining resin must be kept away from light or returned to its storage container. The resins themselves may be highly toxic and handled with extreme care, requiring the use of safety equipment (eye protection, gloves, etc.).

The part must now go through additional steps called “post-processing”. The part must be washed to removed any remaining resin from its surface. Using a tool, you must remove the support structures (while not damaging the print). The part must then go into another machine that exposes the part to UV light to further cure the resin and fully harden it.

SLA VS. FDM: OVERALL COST

Depending on who you purchase your FDM 3D printer from, FDM can be the least expensive 3D printing technology. A commercial 3D printer that is fast, with a large build volume and reliable (as found with the Fusion3 F410), will be inexpensive to own and maintain. If you are able to purchase filament on the open market, your cost for materials will be low and your cost per part will be negligible.
SLA can be an expensive 3D printing process. The lasers and mirrors involved can be costly and the cost per part can be prohibitive due to the expensive of purchasing proprietary resins from each printer manufacturer.

SLA VS. FDM: CHOOSING FOR THE RIGHT TASK

How would I choose between SLA 3D printers and an FDM 3D printer for my specific task?

 

You might select an SLA 3D printer: You would likely select an FDM 3D printer:
Complex, detailed prototypes Rapid prototyping
Cost is no object Selection of colors is needed
Smooth surface, fine detail, and accuracy is necessary Required to stay within a reasonable budget
Strength & durability is not crucial Strength & durability is important

 

The F410 features the widest range of printable materials,
2-year warranty, and a print volume that no SLA or FDM printer can match

To learn more and request a sample part