FFF VS. FDM
The name-only difference between fused filament fabrication and fused deposition modeling comes down to a legal issue.
FDM is trademarked by 3D printer manufacturer: Stratasys, Ltd. Stratasys founder S. Scott Crump, the inventor of fused deposition modeling, trademarked the term in 1991 shortly after he developed the 3D printing process. This means only Stratasys products can use the phrase “fused deposition modeling” in their marketing and product names.
This created some problems for other companies interested in developing similar technology. To solve this problem, it became commonplace to use the term “fused filament fabrication.” This allowed people and companies to discuss and develop 3D printing technologies without the fear of being sued for using the FDM trademark.
THE PROBLEM WITH SHARING SIMILAR TERMS
Though this might seem like an easy solution, it creates some problems. For people who aren’t familiar with the history of the FFF vs. FDM dispute, it can be easy to assume that the two technologies are totally different.
This is problematic when communicating ideas about 3D printing to the public. The average person isn’t going to be aware of this history, and thus might find it confusing to read about these two seemingly disparate means of additive manufacturing.
If, for instance, the owner of a fused filament fabrication printer wanted to learn more about how it worked, they may pass over perfectly helpful guides or articles because those guides only refer to fused deposition modeling or vice versa.
Similarly, manufacturers of 3D printers could run into problems if they advertise their product as using fused deposition modeling techniques without realizing that the term is trademarked. Though “fused filament fabrication” is generally the preferred term, its usage isn’t ubiquitous. The lack of communication this creates across the 3D printing industry can hamper communication and innovation and can make marketing products to consumers complicated or confusing.
HOW FFF/FDM WORKS
FFF/FDM is the most popular 3D printing method because of its relative inexpensiveness and ease of use.
The 3D printing process starts with a 3D model made in a modeling program like Blender. The printer then builds a physical object from the 3D model by laying down layers of material called filaments with a heated nozzle or extruder. The heated layers are placed and fused on a flat printing bed.
Beyond this basic system, the workings of FFF/FDM printers can vary slightly depending on the model type.
- Cartesian 3D printers, thus named for the cartesian coordinate system, typically have a printing bed that only moves on the z-axis. The extruder moves in four directions on the x- and y-axes. These printers are the most widely available.
- Delta 3D printers also use the Cartesian coordinates and are designed for speed. The printing bed never moves; instead, the extruder moves freely across all coordinates.
- Polar 3D printers, unlike Delta and Cartesian printers, use a polar coordinate system; this means each coordinate point on the grid is based on its relation to a variable pole, rather than to a set origin.
FFF/FDM printers also have a variety of extrusion systems—that is, the system through which the printing material is applied. These can include:
- Filament extruders, which use thermoplastic filaments
- Pellet extruders, which use granules of plastic instead of filaments.
- Paste extruders, which can use any kind of paste. “common uses are with ceramics and food. Paste extrusion is sometimes left in its own category, as the paste is not a thermoplastic material.”
THE PROS AND CONS OF FFF/FDM
FFF/FDM printers are great because they’re relatively inexpensive and easy for newcomers to use. They’re the ideal entry-level tool for people to dip their toes into the 3D printing world. The fact that they’re on the lower end of the 3D printer spectrum comes with some drawbacks, though, namely as they relate to the quality of the objects they produce.
ADVANTAGES OF FFF/FDM
FFF offers many benefits to consumers and businesses alike. Since many printing materials are inexpensive, 3D printing allows people to make just about anything they can find a 3D model of in the comfort of their own homes.
FFF and FDM printers are also cheaper than some other alternatives—the RepRap project even developed a way to use FFF and FDM to create self-replication printers! That means if you have one RepRap printer, you can make one for your neighbor too.
Another benefit is the scalability of FFF/FDM printers—the only limit is the size of the gantry rales on which the extruder moves. Since the cost of parts is low, it’s relatively inexpensive to make large FFF/FDM printers that can go on to produce massive 3D printed goods.
DISADVANTAGES OF FFF/FDM
However, FFF/FDM comes with some drawbacks. Because the layers are stacked one on top of another in a set order, they end up being weaker in the direction perpendicular to the stack. This can be overcome by adding support elements, but this costs extra time and materials. Making high detail prints is a challenge as well since the material is extruded in layers.
BEST FFF/FDM PRINTERS FOR CONSUMERS
By now, there is a wide array of FFF/FDM printers available, so many that it might be overwhelming for the average consumer. Some of the best FFF/FDM printers on the market include:
- MakerGear M3: What makes this printer unique is its double extruders: that means it can print twice as fast as printers with only one. Additionally, MakerGear worked hard to make the internal components relatively easy to understand and maintain in case of failure. If you can change a car battery, you can probably fix a problem with a MakerGear M3.
- Prusia I3 MK3S: The main advantage of this printer is that you can buy it in a DIY kit. This might turn off people who aren’t especially technically inclined, but it can save you a lot of money, and help you learn more about how the model works. In the long run, this will help with maintenance.
- Creality Ender 3 Pro: At $209, this is about the best value for a consumer 3D printer on the market. Like the Prusia I3 MK3S, this is a printer you build yourself. While this may be daunting, there’s a vast online community of Creality Ender 3 Pro users available to help prospective buyers figure things out.
- Monoprice Maker Ultimate 2: One of the great benefits offered by this printer is that its printing bed is fully enclosed, offering protection for filaments that are sensitive to changes in temperature. And unlike some of the other printers on this list, this one comes factory assembled.
- VIVEDINO T-Rex 3: For a discerning customer with a little extra cash to spend, look no further than the VIVEDINO T-Rex 3. It comes packed with just about every feature you could look for in a nonindustrial printer, including Independent Dual Extruders (IDEX), a Filament Run Out Sensor, Industrial Linear Guide Rails.
- BareXY: Like the T-Rex 3, this printer comes with a somewhat heftier price tag, making it more of a prosumer product. Something that makes this printer especially interesting is its use of a unique extruder/bed movement system called CoreXY. Without getting bogged down into the technical details of this system, CoreXY allows the dual extruder carriage to be much lighter, allowing the extruders to move (and thus print) much faster than some other printers.
WHAT KIND OF MATERIALS DO FFF/FDM PRINTERS USE?
According to 3D Insider, there are a wide variety of filaments available for FFF/FDM printers, all of which have their own uses, pros, and cons.
(Source: 3D Insider)
ALTERNATIVES TO FFF AND FDM
Though FFF/FDM is the most common 3D printing process, especially at the consumer level, it is not the only one. In fact, there are many categories of 3D printing technologies, each with their own subcategories of machines.
FFF/FDM printers belong to the category of material extrusion printers. These printers all push heated filaments through a nozzle that, when hot, combine to take the shape of the desired printed object.
Other types of material extrusion printers include:
- Stereolithography (SLA): SLA lays claim to the fact that it was the first 3D printing technology ever developed. It was invented by Chuck Hull in 1986. SLA printers use mirrors called galvanometers placed on the x- and y-axes. The galvanometers carefully aim a laser at a supply of resin, solidifying it into a given shape layer by layer. This process works but can be lengthy.
- Digital Light Processing (DLP): DLP works similarly to SLA, with the primary difference being that DLP uses a digital light projector to flash a cross-section image of each layer all at once, rather than by composing each layer one piece at a time. Think about it as tracing an image as opposed to copying it free-hand. The image of each layer is made up of square pixels, which, when stacked, create small cubes called voxels, which together compose the layer.
- Masked Stereolithography (MSLA): MSLA works similarly to DLP, except that rather than using a digital light projector, it uses an LED array as its light source. Since LEDs are relatively inexpensive, MSLA is a very popular printing method.
OTHER PRINTING METHODS
Outside of material extrusion printers, other 3D printers vary in the materials and methods they use to print objects. Some use powders as their base material; others use droplets of material. Different printers might construct objects in a different order, adding different parts at different points. All in all, 3D printers are diverse in their manufacturing methods.
- Powder bed fusion: Powder bed fusion uses heated powder polymers rather than thermoplastics to print. A heat source is guided to selectively fuse parts of the material. There are powder bed fusion methods that use both nonmetals and metals.
- Selective Laser Sintering (SLS) is the only standard powder bed fusion method currently in use that doesn’t use metal powders. It works by heating a polymer powder to just below its melting point. A thin layer of the powder is then deposited onto the build platform. A laser selectively cuts through the object to create a cross-section. This process repeats until the object is complete.
- Direct Metal Laser Sintering (DMLS) works similarly to SLS, except that it uses metal-based powders rather than polymers. The metal powders are heated to the point where they can fuse on the molecular level.
- Selective Laser Melting (SLM), unlike SLS and DMLS, actually melts the powders down to produce a homogeneous metal. This process requires extra structural support during construction due to the potential for distortion caused by the liquified metals. Due to the high temperatures involved, SLM increases the risks of warping. The same applies to DMLS.
- Electron Beam Melting (EBM) uses a focused high energy beam of electrons to superheat particles of metal powder, causing them to fuse. According to all3dp.com, “compared to SLM and DMLS types of 3D printing technology, EBM generally has a superior build speed because of its higher energy density. However, things like minimum feature size, powder particle size, layer thickness, and surface finish are typically larger.”
- Material jetting (MJ) involves applying droplets of a given building material to a build plate. The advantage of this method is that it allows for different droplets—i.e., different printing materials—to be used in the same project, allowing for a diverse variety of creations. Rather than following a single path to build a cross-section of an object, MJ printers deposit droplets line-by-line.
- Drop on Demand (DOD): DOD printers use two inkjets, one depositing building material, the other depositing dissolvable support materials. A fly-cutter skims the surface of the object after each layer is complete to make sure it is perfectly flat.
- Binder Jetting uses a liquid binding agent to combine regions of powder. It’s similar to SLS, except for the fact that Binder Jetting uses a droplet-depositing printhead to construct layers without the use of a laser. Binder jetting comes in two varieties:
- Sand Binder Jetting uses low-cost, sand-based materials. This method is useful because of the high cost-to-production ratio.
- Metal Binder Jetting uses essentially the same process as sand binder jetting, except with metal components. This makes the process a bit more complicated. All 3D Printing notes that “functional metal objects can only be produced via a secondary process like infiltration or sintering…Without these additional steps, a part made with metal Binder Jetting will have poor mechanical properties.”
THE WIDE WORLD OF 3D PRINTING
As you can see, the complexities of 3D printing go far beyond FFF vs. FDM. Though filament extrusion printers are the most used on the consumer level, a wide variety of models and technologies exist, each with their own quirks and purposes.
3D printing represents a new horizon in terms of manufacturing, both for consumers and businesses. As 3D printers become less expensive and more widely available, there is no telling what the future will hold. It’s a brave new world.