FDM vs SLA – A Brief Guide

Some companies charge more for similar items than others would. Did you ever wonder why? Learning about FDM vs. SLA printing might help.

Explanation of FDM vs. SLA Printing

The differences between FDM and SLA technology affect worldwide corporations, local businesses, and individual consumers. This brief guide will explain why either FDM or SLA printers would benefit 3D object creators in specific instances.

FDM 3D Printing

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You might imagine glue coming out of a hot gun when hearing how FDM equipment works. It’s like that but with one difference: The ABS or PLA filaments resemble sewing threads rather than a “glue stick” before heated. A single line of filament is usually sent through the FDM printer the way a sewing machine sends fabric string through it.

Consumer industries typically use FDM printers to produce polymer 3D objects from the ABS or PLA “strings.” Heat applied as the 3D printing materials dispense from the application gun causes these strings to melt. While still hot, multiple plastic layers bond together to form a single object.

In case you’re wondering, FDM stands for “fused deposition modeling,” and ABS stands for “acrylonitrile butadiene styrene.” The PLA abbreviation refers to “polylactic acid.”

SLA 3D Printing

SLA Printing
image credit: karkhana.io

Stereolithography printing uses a laser to turn liquid resin into the stiffened plastic material. This SLA 3D printing process uses either visible or ultraviolet light to activate the photopolymerization process that makes moldable modeling materials.

Engineering and manufacturing companies often use the SLA printing technique for making prototypes, molds and patterns or machine parts. Although FDM objects have similar durability, the liquid SLA material seems to meld individual layers more into one than the FDM printer does.

3D Materials Used Besides Plastics

FDM and SLA both usually take some type of polymer plastic material. However, some printing machines also produce objects from other materials such as metal, ceramic, concrete, or a combination of these.

FDM vs. SLA Printer Advantages

Speed

FDM printers produce 3D objects faster than SLA ones do. FDM machines work well when inventors, students, and manufacturers need prototypes during the early product development stages.

Printed 3D object appearance doesn’t always matter until public release to science contests, retail stores, product demonstrations, etc. However, FDA printing produces prototypes by project deadlines without wasting too much money on materials.

Applications

FDM filaments can create a variety of textured surfaces, and it does quite well quickly, unlike some SLA materials. Therefore, you might see FDM printers used when creating flooring that looks and feels like wood. It also applies to making customized theater face masks and textured “skin.”

FDM printers also make several types of action figures that don’t require a smooth finish. FDM also makes decent items for both consumer and educational use. In addition, manufacturers prefer it for efficient test object creation.

Some items you could possibly make using an FDM printer include as follows:

  • Machine part prototypes — FDM draft printing helps students and researchers test how devices work before spending multitudes of dollars on high-quality 3D materials.
  • CPR class bodies — 3D printing is already changing the way life-saving classes are held by creating CPR bodies for demonstration.
  • Medical anatomy replicas — This includes realistic-looking skeletons, skulls, or internal organs. They might not appear as precise as with an SLA printer, but students and patients get the idea.
  • Crash test dummies — This especially helps the automotive industry, but it could refer to any machine undergoing safety tests.
  • Household goods — Cooking utensils, storage containers, pens, clips, desk organizers, and more are some items made with FDM printers.

Materials

Although not as easily usable as SLA for flexible or elastic printing, alternative materials make FDM 3D object creation easier. Not all FDM printers can use these materials either. Keep that in mind.

Additional thermoplastic options besides ABS or PLA for FDM printing include the following:

  • Nylon — It provides a range of flexibilities and softness or hardness grades.
  • TPU — This thermoplastic polyurethane material enables FDM printers to make transparent, translucent, or elastic objects. It also improves the making of oil- or water-resistant merchandise.
  • PETG — A primary application is for creating disposable or reusable water bottles.
  • PEEK — Manufacturers use this polyetheretherketone material to make an assortment of consumer and industrial objects. It’s not always recommended in cases when lower-cost materials could perform the same function.
  • PEI — Polyetherimide has some of the same properties as PEEK, but it doesn’t resist head or impact, as well as PEEK does.

Quality

Manufacturers prefer FDM over SLA when they want to mass-produce items for consumer use. This enables companies to produce plastic toys, kitchen utensils, game parts, organization containers, shelving, and more.

The quality might not meet requirements for medical, manufacturing, or food service industries. However, consumers don’t seem to mind paying less for common household items where function versus “fashion” remains the priority. FDM does an excellent job of helping retail customers save money on necessary home equipment.

Concerning FDM vs. SLA, FDM printing machines will produce objects sturdy enough for demonstration in less time. This benefits inventors, students, and researchers seeking funding for future testing and development. 3D object creators can meet grant and loan application deadlines much quicker if using FDM vs. SLA printers.

Precision

FDM printers might not offer the fine detail that some SLA 3D object printing machines might. However, that doesn’t mean that FDM printers cannot create accurate gear matches for machine movement. It also doesn’t mean that the FDM vs. SLA printer can’t produce strong enough axels, wheels, or hardware.

The FDM printer will offer as much precision as required by most consumers. It also does an excellent job of making various components work with precision the way a customer expects. This includes electronic or computer parts such as keyboard keys or watch gears.

Increased accuracy for tiny electronic parts might occur using an SLA printer. However, production plants still make a substantial profit selling FDM-printed consumer merchandise.

Ease of Use

The one FDM printer attribute that makes it easier to use than the SLA type is speed. You can generate decent prototypes in less time than with the SLA printer. If you have an upcoming board meeting or grant proposal deadlines, you’d want to probably use the FDM, not the SLA.

If using an FDM printer for the first time, just take a few moments to learn how it works. It shouldn’t take long to start printing quality 3D objects in various development stages intended for consumer use. You probably can become accustomed to the printer’s functions in a few hours or less.

Return on Investment

You can start out with a low-end FDM printer and still find a market for your products. Perhaps you would only have to pay $300-$400 for a “starter printer.” This will help you become acquainted with FDM 3D printing before you jump to spending $2000-$8,000 on one.

No matter what FDM printer you buy, you will receive an ROI on your device based on your profit goals. If using the less expensive printers, keep your marketing plan simple. Perhaps, you could produce everyday items such as rubber scrapers or pens. Maybe you could also make promotional items such as plastic cups, bag clips, or other items with logos on them.

Don’t try to make industrial-grade machine parts with an FDM printer. This could cause you to lose all the money you invested in “a minute.” You would need an SLA for that, probably. However, you can still make a profit using FDM devices if you create mid-grade, useful consumer items.

SLA vs FDM Printer Advantages

During final product testing stages, the SLA could prepare your objects for public release better than an FDM printer. This applies not only to printing 3D objects intended for consumer sale, but it also pertains to 3D machine parts created for industry use.

SLA machines generate 3D objects at quality levels required by medical, educational, and industrial and engineering sectors. They also provide benefits for creating higher-grade consumer products than FDM printers. Some space technology also deploys SLA printing techniques.

Draft Resin Speed

Although FDM seems to have the speed advantage overall, SLA draft resin does produce objects 10 times faster than an FDM printer. This depends on the SLA device capabilities, however. It’s something to consider before you embark on your 3D printing journey.

Applications

  • Restorative dentistry objects (experimental) — By 2021, dentists have already had five years of experimentation with using a 3D printer for making teeth veneers, crowns, inlays, and onlays. This usage does require more research to make sure it meets professional standards, but it does have quite a bit of potential.
  • Medical anatomy models — FDM polymer makes human skulls and skeletons, internal organs, and CPR models or body parts for demonstration. The medical use also includes creations of prosthetic hands, legs, feet, and other appendages. In addition, SLA printers could create various surgical implants.
  • Educational projects — Some of the same models used in the medical field also work well for teaching biology. Endless opportunities also arise using SLA-printed objects to teach physics, astronomy or art classes, and more. Trade classes such as auto mechanics or machine operating also might utilize 3D objects products with an SLA printer.
  • Machine parts — Manufacturing companies need machines to run with precise timing. For instance, the gears need to operate in tune with detectors. All mechanical parts also need to contact one another to create the movement needed for assembly line production. SLA printers could provide this benefit more so than FDM when material properties matter.
  • Household objects — The SLA printer offers chances to make cookware and storage containers or tools of brand-name quality. It also could high-end artistic décor for any dwelling space. Items made with an SLA printer might cost more. However, the finished merchandise might show more carvings and design intricacies than FDM-printed items.
  • Toys — Toys produced by SLA printers might last longer than items constructed with FDM printers. Maintenance becomes easier with SLA-produced items because they absorb less water and other liquids.

3D Object Maintenance

For fabricating air-tight consumer and industrial objects that also resist water, manufacturers may prefer SLA over FDM. The stiff but smooth, non-porous material only usually requires a quick wipe with a damp towel and mild detergent to remove dirt. Items made with an SLA printer also might resist sticky food residue, grease and grime, and toxic materials more than FDM-made objects.

Quality

SLA-produced 3D objects seem to have a more professional quality than FDM objects. They come out of the machine with a smoother surface finish, and manufacturers rely on the SLA printer’s accuracy. After all, no room for error exists when creating lug nuts, gears, fasteners, axles, and more.

SLA 3D objects appear smoother at the surface than FDM 3D objects. It’s because the SLA printer creates a chemical versus a mechanical plastic bond. Therefore, individual layer lines would less likely show up once the 3D object plastic hardens. The surface texture and single-color appearance give any merchandise made with an SLA printer a “high-class” appeal.

When quality matters the most, the healthcare and dental industries would more likely choose SLA objects over FDM objects. It just seems to produce higher grade items overall, depending on printer capabilities.

Precision

For making precision machine parts, the SLA often is preferred over FDM. SLA produces finer details, such as what would show up on plastic animal toys. Furthermore, correct placement of holes, threads, joints and more often happen easier using SLA printers.

Versatility

SLA materials start as a liquid, so mixing them with glass, ceramic, or other additives seems easier. Doing the same with various FDM filaments that start out as solid might not happen as easily as with an SLA printer.

Observing how a 3D object might react to extreme heat or cold also could happen easier if using SLA resins instead of FDM filaments. Additionally, the resin seems to create flexible or elastic objects easier than the solid later melted into liquid might. For instance, SLA printing often creates goggles, handle grips, or silicone seat cushions with ease.

The FDM materials might not offer as many applicable uses as the SLA. However, exceptions apply if using TPU or another more flexible FDM material.

Room-Temperature Printing

A quality unique to SLA printing is producing 3D objects at room temperature. Unlike with FDM printing, this enables you to prevent the expansion and contraction of objects ordinarily caused by heat. That’s because the SLA printer uses light instead of applying hot temperatures required in some FDM printing applications.

Ease of Use

Projects created with an SLA printer might not require as much climate control as FDM printing projects do. Therefore, creators can use them easier in general office spaces.

For some applications, the FDM printers might require advanced ventilation or air conditioning. The SLA setup might not need this, but that also depends on intended usage and types of objects created.

An additional benefit that makes SLA machines easier to use is their plug-and-play technology. Sometimes, you can use them almost as soon as you press the “power on” button. It might require a bit of minor training, however, if you never used an SLA device in the past.

SLA Return on Investment

You’ll probably pay at least $3,000-$10,000 for a high-quality SLA printer. However, you also have the opportunity to conduct large-scale infrastructures and tiny precision machine parts. This could make you thousands, millions, or even billions of dollars with the right invention.