Fused Deposition Modeling - The 3d Printing Method You Should Know

A number of methods currently exist to perform 3d printing and the number of methods will probably continue to grow over time in the near future considering technology evolves so much anymore that it is hard to keep up with (just think of how your new smart phone is only cool for about a month because a new one comes out making your revolutionary device old news), but for now, Fused Deposition Modeling (FDM) is one of the most popular today.
Fused deposition modeling is a form of additive manufacturing technology which is most widely used for modeling, prototyping, and production applications. I think FDM is probably the most popular because it definitely seems to be the simplest method to understand and develop compared to the other newer methods that can get pretty confusing for a newbie.

Many people seem to think that 3d printing is a very new technology but it has actually been around for quite a while. The 3d printing method known as FDM was invented in the 1980s by Scott Crump who happens to be the co-founder and the chairman of Stratasys LTD which also happens to currently be one of the big names in the manufacturing of 3d printers.


So how does this method work?

Well, the start of the FDM process begins with the use of 3d modeling software which involves the creation and modification of a .STL file. STL stands for stereolithography which is a type of file format used for both 2d and 3d modeling. Just think of how a word document file usually ends in .doc when you save it. The STL file is the same concept as .doc but in this case the STL means it was created with 3d modeling software. One can find a wide variety of 3d modeling software on the internet which offers solutions for both beginners and advanced users.

The most commonly used material for the FDM process is thermoplastic which is a plastic that is very flexible once heated past a certain temperature (hence the terms used in the word thermo and plastic), known as the glass transition temperature, and keeps the form it was forced into once it is cooled and becomes hardened. The nozzle through which the thermoplastic gets pumped through is heated so that the thermoplastic reaches the temperature needed to make it flexible during the extrusion process.  Thermoplastics are a great material for those looking to quickly create prototypes of a wide variety or specific type of models.

Fused deposition modeling creates 3d objects by pouring out materials in layers which could possibly be compared to the way a soft serve ice cream machine works. A soft serve machine actually uses a mechanism similar to the one used by FDM which is known as extrusion. The process of extrusion is the forcing of materials through a piece of equipment known as a die in the 3d printing industry.

Here is a cool video of this technology at work!

A die is nothing more than a nozzle of sort which is shaped a specific way to make sure that the material being extruded (pushed out) comes out in the proper shape or form for the object being made.  The concept of using a die is similar to the changing of the settings on a garden hose which usually gives you the option of a light mist, strong stream, rain shower of sort and so on. Except in this case it is not water being forced through a nozzle it is the thermoplastic (mentioned earlier) that is being forced through the extruder.

Thermoplastics are  a popular choice for this process because they come in a wide variety of qualities that vary with different sizes, strengths, weights, and colors.

 The material also has pretty low processing costs compared to materials like metal which can get quite expensive especially when making prototypes which adds to the reasons that it is a very multipurpose and popular material. The common computer keyboard is a product made with thermoplastic and you can see how flexible the material is by noticing all of the different shapes that are on a keyboard. (a very basic example but also a very common one) Another popular example of products made with thermoplastics is PVC (polyvinyl chloride) pipe that you have probably seen laying around your house during a plumbing repair or you probably seen a variety of them during an adventurous trip to home depot.

The main disadvantage of 3d printing using thermoplastics is that it is possible for the material to melt when exposed to certain levels of heat which are much lower than the heat that would be required to melt a stronger material like metal. A couple types of lower quality thermoplastics tend to melt when they are exposed to ultraviolet light for long periods of time so leaving your newly 3d printed figurine of your favorite pokemon in the sun might be bad news. Lower quality types also tend to weak and slightly collapse, depending on the shape, while other types simply break instead of slowly collapsing when under the stress of heavier weight. So although the use of thermoplastics is cheap and efficient, it definitely seems to be best for short term uses like prototyping compared to long term uses such as being a support beam for a building that would deal with heavy weight.

What are the different types of thermoplastics used for FDM?

ABS (acrylonitrile butadiene styrene) - probably the most popular among thermoplastics used in 3d printing because of its light weight, affordability, and wide range of colors. Various versions of ABS exist for different needs of the object(s) being printed. ABS is most popular among machines that are designed for beginners who want to give it a try for themselves without having to worry about spending a lot of money on materials.

PC (polycarbonate) – a well liked material because of its durability and precise dimensions when produced. It has great mechanical properties and also a very high heat resistance of 280 °F (138 °C) compared to other plastics like ABS that tend to melt in such heat.

Nylon – is very strong with high fatigue resistance meaning it won’t weaken over time after extended use. A good example of the use of this material would be a plastic shovel handle that carries various loads of weight but does not bend or break.

PPSF/PPSU (polyphenylsulfone) - material has the strongest heat and chemical resistance of all of the thermoplastic materials mentioned so far. The strong resistance against heat and chemicals makes it a great fit for aerospace, automotive and medical applications which makes perfect sense if you think about all of the processes that take place in those industries that deal with high amounts of heat and chemicals.

The machines sound pretty like they can do some pretty cool stuff… that must mean they are expensive right?

Well not all of the machines cost thousands of dollars like you would think. There are actually a handful of FDM printers on the market for beginners that are under $1,000 and the good news is more and more companies are offering beginner machines for very low prices. The main downfall of the beginner machines is that the quality of the finished products might not be the highest quality but then again these machines are for beginners after all. It also seems that a lot of the really cheap machines are funded via Kickstarter campaigns, and other similar campaigns, which means that the product you want may not be available for sale until the near future, but once again still a great way for beginners to spend a small amount of money to experiment without worry.

Here are some of the affordable machines

·         Printrbot’s Simple Maker’s Kit – this machine requires some assembly but nothing too crazy. Price : $259-$999

·         Romscraj’s Portabee Go – Has the unique ability to fold and unfold without having to worry about much assembly. Price: $375 - $500

·         Pirate 3D’s Bucaneer – Fully assembled printer that works out of the box and is also has Wi-Fi capability allowing you to use communicate with the machine via their app with iOS and Android. The Bucaneer uses a process called fused filament fabrication which is basically identical to FDM. Price: $399 - $999

·         Solidoodle – Fully assembled printer that works out of the box that offers different generations (versions) of machines. The main differences between the different versions of machines is their size along with a few other specs that probably wouldn’t be understood, or needed, by a beginner. Price: $499 - $799

·         RigidBot – Offers their machine (the RigidBot) to arrive at your door fully assembled or in kit form for those who prefer to assemble their machines. The RigidBot kit allow users to customize their machine to fit the dimensional needs of the objects being printed which requires some more advanced knowledge of these sort of machines. Price: $499 - $959

·         Robo – The Robo printer’s standout feature is that it is open sourced meaning all info about the Robo can be found online. Robo gives users the ability to build their own custom machine as well allowing a wide range of production possibilities. Price: $799

Prototyping sounds kind of boring… what else is FDM used for?

I agree prototyping is boring but the many industries that use it make it sound much cooler!

AeroSpace – designing various tools and parts of spacecraft that are very important for making sure a mission is safely done. FDM is becoming more and more popular for astronauts that might need to make a new tool or a new machine part during a mission that would otherwise probably cause them to improvise.

Commercial Products – Aside from boring prototyping, manufacturers are discovering that products can be made solely from FDM when using higher quality plastics making the old assembly lines feel left out. (tear sniff)

Dentistry – Did you ever chip, or break, a tooth and have to get a crown for it? Well now 3d printing is making the production of crowns, and other dental products, much more efficient and accurate in terms of design to ensure the crown fits perfectly for the patients needed repair. I have personally received a crown on a broken tooth which was not well designed to fit my mouth and it was not a very fun experience if you could imagine.

Medical – The medical industry, like the other industries mentioned, truly has endless opportunities for advancing the technology used in various medical aspects. One field of the medical industry I see making rapid improvements with this technology is prosthetics because limbs, and other body parts, will be made much faster and more precise to suit the patient’s needs as much as possible. Other more advanced procedures such as artificial heart replacement surgery could also be made more efficient and safe thanks to the 3d printing technology offering the much needed precision when constructing an extremely vital organ like the heart.

Consumer Products - A wide range of possibilities exists from toys for kids to tools for adults that would give stores the ability to produce custom products in a very short amount of time, or consumers could simply download an .STL file and create the product at their house. I expect a lot of cool things to be created thanks to this 3d printing method.

Education – Remember having to do gross dissections of small animals in anatomy class in high school? Well, thanks to FDM’s ability to make highly detailed models, the need for such things like dissections could possibly no longer be a concern since full scale plastic models will be available and able to be used over long periods of time. Aside from biology and anatomy, a wide variety of school subjects will benefit from having such detailed models available for the subject being taught. Instead of using a paint brush, students in the near future might be designing and printing artistic statutes for art class.

Automotive – One of the biggest obstacles with keeping the automotive industry efficient is the availability of tools and car parts, but this technology will give mechanics and/or dealerships the ability to make the needed tools or parts right in their building without having to wait for the UPS guy to arrive. Aside from automotive businesses, consumers could possibly benefit as well in the event that a new tire is needed one will probably have the ability to print their own in the near future.

Defense – The branches of the military can now take advantage of making prototypes of new ideas ranging from firearms to spacecraft to disguises (feel free to let your imagine run wild on this one)

Entertainment – When people think of industries that will benefit from 3d printing technology the entertainment industry is probably one of the last ones they will name off of the top of their head, but an industry that relies on props, masks, and so on will definitely find this technology very useful. A production company making a horror movie will have a great time designing their scary bad guy’s mask knowing that the machine will make it exactly as they want, or you could even think of an action movie that could 3d print the guns to be used during an epic shootout scene.

Even though fused deposition modeling is not as new of a concept as you might think, it is obvious that it's popularity has not spread much until recently with the news releasing one crazy story after another showing how endless the number of opportunities are for this revolutionary technology.