Fused Deposition Modeling (FDM) is the most popular process used in 3D printing. It can create durable, long-lasting, and strong parts that are digitally precise and accurate. If you're looking to learn more about this innovative technology, you've come to the right place! Below you’ll find a complete introductory guide on FDM 3D printing.
An Introduction to FDM 3D Printing
FDM technology is the most commonly used method of 3D printing. FDM stands for Fused Deposition Modeling and was first developed in the 1980s. It uses a thermoplastic filament that is heated until it melts. The melted filament is then extracted, layer by layer, to create a three-dimensional object. There are actually two different aspects to this process. One is the modeling material that makes the object itself, and the other is the support material that acts as scaffolding to support the object while it’s being printed.
The process of FDM 3D printing is quite advanced but the method actually followed to create your 3D objects has been simplified. Usually, you will start out with a computer-aided design file or .CAD file. This file is then converted into either a .STL file or .OBJ file in order to be processed by the FDM 3D printer.
Once an object is ready to be printed, the FDM 3D printer starts by loading filaments into a nozzle. The filaments are then heated up until the point of melting. A computer communicates with the nozzle, or extruder, and base of the printer and tells it exactly where to move in order to create the object accurately. Then, the melted thermoplastic filament will be extruded from the nozzle as it moves over the base to create the first layer of the object. As each layer cools and hardens, another layer is added on top of it and immediately binds to the one below it. As each layer builds, the base will move lower to allow room for more layers.
When the object is done printing, the thermoplastic supports can be snapped off by hand and sanded if needed.
The Common Types of FDM 3D Printers
FDM 3D printers have evolved throughout the years. They are now becoming more modern, sophisticated, and advanced. That also means you have your choice of several different types. Read more below about the most common types of FDM 3D printers, including their advantages and limitations.
The most common type of FDM 3D printer is the Cartesian. This is a boxy type of design where the base moves on the Z-axis and the extruder moves on the X and Y-axis. This three-axis system is based on the Cartesian coordinate system in mathematics, which is where the printer derives its name from. There are some variations but most work in this fashion.
Advantages: Simpler design, easier to maintain, detailed, precise.
Limitations: Speed. Cartesian 3D Printers can be quite slow. Most other types created after this design worked to improve on the speed.
Delta 3D printers have a circular base with the extruder suspended at the top. The nozzle is supported by three metal arms that form a triangular shape (or a delta symbol). Delta 3D printers are also unique in the fact the base never moves, unlike most other common types. This can offer an advantage when creating certain types of objects.
Advantages: Faster than most other types, a modern design, stationary base.
Limitations: It is said to not be as accurate or detailed as the Cartesian types.
Polar 3D printers are a newer design that works on a different type of coordinate system. Whereas the Cartesian 3D printer works on the Cartesian coordinate system (a square grid), the Polar 3D printer works on the polar coordinate system (a circular grid). With this type of printer, the base can spin around while the nozzle can move up and down and left to right.
Advantages: Can make larger objects in less space, runs on two motors rather than three which makes it more energy efficient
Limitations: It’s still an emerging new design and not as well-known as others.
Scara stands for Selective Compliance Assembly Robotic Arm. If you watch a Scara 3D printer in action, it almost looks like a robotic system from a manufacturing factory. It is very precise in its accuracy and due to its flexible position, it can make more complex objects.
Advantages: Can make more complex structures, more mobile design since it is not fixed to a base.
Disadvantages: It’s still an emerging new design. It is also said to not produce as high-quality products as the Cartesian.
The Common Types of FDM 3D Printing Materials
Here we will cover the most common types of FDM 3D printing materials. We will also discuss exactly what they are, what they’re good for, and any drawbacks they may have.
PLA stands for polylactic acid or polylactide. It is a biodegradable thermoplastic that is created from renewable resources. PLA offers good detail, is affordable, and easy to print with. While it offers high stiffness, it has a low impact strength.
ABS stands for acrylonitrile butadiene styrene. It is a thermoplastic polymer. ABSoffersimproved mechanical and thermal properties over PLA but less detail. It has a low production cost and excellent impact strength but may be susceptible to warping.
TPU stands for thermoplastic polyurethane. It is a class of polyurethane plastics that is flexible, transparent, and resistant to oil, grease, and abrasion. It is best suited for tubes, grips, seals, and gaskets. While it is very flexible, it doesn’t offer a high print accuracy.
Nylon or polyamide (PA) is thermoplastic silky material. It has great wear and high abrasion and chemical resistance. It is very high in strength but has low humidity resistance.
PEI stands for polyetherimide. It is an amorphous thermoplastic that is amber-to-transparent. It is an engineering plastic with high-performance applications. PEI also has excellent heat, chemical, and flame resistance. It has a very good strength to weight but can be costly to use.
PETG stands for polyethylene terephthalate, while the G is added to indicate it has been glycol modified for extra durability. It has improved properties over PLA, making it more impact-resistant with exceptional chemical and moisture resistance. It can be sterilized making it food safe. PETG also has good strength, is flexible, and can be easy to print with.
The Advantages and Limitations of FDM 3D Printing
The main advantages of FDM 3D printing over other forms of printing are its low cost, ease of use, and a broad range of materials. Compared to other techniques, FDM 3D printing is much more affordable and therefore more accessible to the average buyer. The process is user-friendly and easy to use. Also, as you saw in the last section, there are many different types of filaments you can use. This can allow for the use of different types of material in one project. They also come in a wide range of colors and levels of opaqueness.
The main limitations of FDM 3D printing include being limited to plastics, may not achieve super detailed objects, and more work can be involved when removing supports. It should be noted that FDM 3D printers are the best type for home and office use. While other types of 3D printers can make objects out of ceramic or glass, the types of materials needed can be very dangerous and therefore should be reserved for professional 3D printer operators.
Common Application Fields of FDM 3D Printing
For a long time, 3D printing was very expensive and therefore out of the reach of most people. Now that it is starting to become more affordable, FDM 3D printing is now used in all types of fields. Below you’ll find a list of the most common applications of FDM 3D printing in various fields of study.
Used for bio-printing, medical devices, replicas of organs, pills, and implants.
Mass customization, rapid prototypes, rapid manufacturing, and in research labs.
Clothes, shoes, jewelry, cars, construction, computers, robots, and art.
Art, jewelry, hobbies, educational use, and environmental use.
The Future Prospects of FDM 3D Printing
FDM 3D printing is the new wave of the future. The technology is evolving and growing every day and its uses are only increasing. While there are many incredible things already being done with FDM 3D printing, the future growth is exponential. The medical industry is already making printed organs and the construction industry has started to look into 3D printing to build houses!
Even though there are many industrial and research applications, FDM 3D printing can be ideal for the tinkerer, maker, or hobbyist. Your imagination is truly the limit. Do you need a part for a small fix around the house? Print one up! Are you looking to create unique art or advanced robots? FDM 3D printing can help with that, too. If you can dream it, you can print it!