As fused deposition modelling (and its close relative, fused filament fabrication) evolved over the years, it has become better and better, gradually ironing out its few disadvantages.
The technology is now so mature that it has more pros than cons. But what are the advantages (and disadvantages) of FDM 3D printing that you should be aware of?
The primary advantage of fused deposition modelling is that it is an affordable way to 3D print, allowing almost anyone the opportunity to build their own models. On the other hand, the main disadvantage is that the printing quality isn’t always what you would like it to be.
All the 3D printing technologies can quickly become confusing, especially with acronyms like FDM, FFF, and SLA that translate to highly technical terms.
So, when you’re thinking about 3D printing your components, it’s best to know the pros and cons of each before you make a choice.
Let’s examine the advantages and disadvantages of FDM printing in more detail.
What Is Fused Deposition Modeling?
Fused deposition modelling, or FDM, is a popular 3D printing technology trademarked and patented by Stratasys. It works by melting filament and extruding it onto a printing bed through a nozzle to form layers. The filament is usually a plastic or composite material, like polylactic acid (PLA).
FDM is often confused with FFF (fused filament fabrication), and though the two are so similar that most people will never notice the difference, they are not identical. However, as far as the advantages and disadvantages go, they are close enough to one another that we can treat them that way.
Fused Deposition Modeling Advantages
Fused deposition modelling is the most popular type of 3D printing, and there’s a good reason for that. It has many advantages, some of which none of the other 3D printing technologies offer.
FDM Technology Is Affordable
FDM 3D printing is one of the most, if not the most, affordable 3D printing technologies. You can buy a cheap desktop FDM 3D printer for as little as £200.
The fact that FDM and FFF printers are so affordable means that they are the ones you may find in most homes, schools, and small businesses, and this popularity is making them even more affordable. You can find replacement parts quickly and cheaply, and many companies can service FDM printers if they fail.
There is no expensive installation and training involved. You don’t have to pay a consultant to set the printer up. You can simply buy the kit and assemble it yourself, saving you quite a large sum of money.
FDM Works With Many Materials
Some 3D printing technologies, like SLA, have limited material options. FDM works with a wide range of filaments, which offers you more choices in terms of price and quality. Some of the filament types include:
- Polylactic acid (PLA): A cheap and easy-to-use filament type, often used as the first step in 3D printing.
- Polyethylene Terephthalate Glycol (PETG): This filament is slightly more expensive and harder to master but stronger and more durable than PLA. It’s an excellent second step after you’ve mastered printing with PLA.
- Thermoplastic variants (TPC, TPE, and TPU): These filament variants offer more flexible, rubbery prints. The models aren’t as sturdy as those printed with PLA or PETG.
- Acrylonitrile Butadiene Styrene (ABS): This filament offers excellent strength, heat resistance, and quality, but it is pretty challenging to print since it requires very high heat levels and releases toxic gases.
- Acrylonitrile Styrene Acrylate (ASA): A modified version of ABS that doesn’t warp as easily and doesn’t release as much toxic gas while printing.
- Nylon (Polyamide, or PA): Nylon is a tough filament to print with since it has specific requirements. But it’s hard to beat nylon in terms of toughness, heat resistance, frictionless operation, and general usefulness.
FDM Models Can Be Very Detailed
You can set the thickness of the layers you print, at least to some extent. This means you can add quite a lot of fine detail to your print. Only the finest of details won’t work well with FDM 3D printing.
FDM Filaments Aren’t Easily Contaminated
One of the frustrations people often face when they 3D print with resin, like with SLA printers, is resin contamination. Since those printers work with resin tubs, it’s easy for dust or other contaminants to get into the tub and contaminate the resin, making it worthless for printing.
Because FDM 3D printing feeds and melts solid filament reels, contamination isn’t as much of a problem. A little bit of dust won’t affect your print’s outcome. In fact, it will probably burn or melt away as the filament passes through the nozzle.
Incidentally, this saves you even more money since the cost of replacing a tub of resin is very high.
You Can Print Large Builds
All 3D printers limit their build sizes by the printing bed size. What makes FDM printing different is the fact that it is infinitely scalable. If you want to 3D print an entire house, it is theoretically possible if you make your 3D printer large enough. This isn’t possible with most other 3D printing technologies; at least, not yet.
If you want to print a large model but your FDM 3D printer isn’t large enough, you can easily split your model into parts and print each separately, then assemble the parts after printing.
Fused Deposition Modeling Is Easy
After the cost, the second reason why FDM is so popular is probably because of its simplicity. If you use an easy-to-use filament like PLA, you can learn how to 3D print a basic model in just a few minutes. The system is logical and easy to understand.
Because of its popularity, there is a wealth of resources available that teach you how to improve your prints using fused deposition modelling. Searching for a problem on YouTube will give endless results where people demonstrate precisely what you need to do to get the best possible FDM print.
FDM Is Relatively Fast
Fused deposition modelling is not the fastest type of 3D printing around; resin modelling still holds that crown. Neither is it fast. It could take hours to print, depending on the model’s size and the settings you choose.
However, that last part is crucial. You can change the settings of your FDM print to the extent that you can print faster than even a resin printer in some cases. When you prepare your model for printing, you can set the printing speed and the layer thickness.
Both of these settings will affect how quickly the print finishes. So, if you want a quick demo of your design with not much concern for print quality, it is possible to print relatively quickly using FDM.
The Disadvantages Of Fused Deposition Modeling
It would not be fair to talk about the massive advantages of FDM if we didn’t give a balanced account. The fact is, as remarkable as FDM is, it does have a few disadvantages, too.
Though FDM can print quite a lot of detail, that detail is still limited. You can change the nozzle size and determine the print output thickness in settings, but you can’t really go finer than 0.4mm. This places a limit on how fine your print’s details can be.
0.4mm is still very good and more than enough for most builds, but it isn’t nearly as fine as the detail you can achieve using an SLA printer.
Quality Isn’t Perfect
The primary strength of FDM 3D printing lies in building your model one layer at a time. Unfortunately, that’s also one of its main weaknesses. This layer-by-layer approach creates a rough surface with lines where the layers meet. This layering will become even more pronounced with a fast print speed.
It’s easy enough to make the surface smoother, but that takes extra time and effort, while SLA printing offers a higher-quality and smoother build right from the start.
Lack Of Structural Integrity
The same layering system we just mentioned also has another negative side-effect: loss of structural integrity. The seams between the layers will always be weaker than the rest of the build because the filament in the lower layers will already have cooled down by the time the printer places the next layer, so the layers don’t always fuse as you would like them to.
You can take almost any FDM printed model and split it or break it by pulling the layers apart. This may not be a problem in most cases, but FDM may not be ideal if you want to print something more robust.
You May Need Support Structures
Depending on what you’re printing, you may have to add support structures as you design your model. Any extended area with no support, like a bridge or the roof of a house, will sag if you don’t add support. Remember, your FDM printer essentially sticks a strip of molten plastic on top of another to make your model. It can’t stick the molten filament to the air.
These support structures take time and careful planning to design correctly since you should be able to remove them without too much effort and while leaving no blemishes on your model. Also, printing the support structures takes more time and uses more filament, wasting some of your resources in the process since you will discard the supports in the end.
FDM Printers May Intimidate New Users
Though the fused deposition modelling printing process is easy to learn, most FDM and FFF printers are sold as a kit, especially the cheaper ones. That means you must assemble the 3D printer yourself, at least to some extent.
Thankfully, most people interested in 3D printing will have enough technical knowledge to figure it out, even if they do so with the help of a user manual or YouTube video. But some people find the assembly more intimidating than learning how to 3D print.
Fused deposition modelling has a few downsides, but the technology behind it has improved so much in recent years. As a result, these disadvantages are growing smaller, leaving only the significant advantages that FDM offers. Especially if you’re just starting in 3D printing, FDM is the best place to learn the essential skills, and it may be the only 3D printing tech you will ever need.