In the world of 3D printing, the FDM process is the most popular and widely used. FDM is a type of additive manufacturing that creates three-dimensional objects by melting and extruding thermoplastic material layer by layer until the object is complete. In this article, I will take a closer look at the FDM process, its characteristics, differences between desktop and industrial FDM printers, applications and usages, advantages and limitations, common materials used, and best practices.
What Is the FDM Process?
The FDM process involves creating an object layer by layer from a 3D model. The process begins by slicing the 3D model into a series of thin layers, typically ranging from 0.1mm to 0.3mm in thickness. The FDM 3D printer then deposits a continuous filament of a molten thermoplastic material onto a build platform, following the path specified by the 3D model. The material solidifies immediately upon contact with the platform, creating a solid layer. The printer then moves up by the thickness of one layer, and the process repeats, with each layer being added on top of the previous one until the object is complete.
How Fusion Deposition Modeling Works?
The FDM process works by using a thermoplastic filament that is heated and then extruded through a nozzle. The filament is fed into the printer, where it is heated to its melting point and then forced through the nozzle. The nozzle moves in the X and Y axes, while the build platform moves in the Z axis. The nozzle deposits the molten material onto the build platform, where it solidifies to form the object’s first layer. The FDM process repeats, with each layer being added on top of the previous one until the object is complete.
The Characteristics of FDM 3D Printers
Build Volume
One of the most critical characteristics of an FDM 3D printer is its build volume. The build volume refers to the maximum size of the object that can be printed in the printer. Typically, desktop FDM printers have a smaller build volume than industrial FDM printers. Desktop FDM printers typically have a build volume of around 200mm x 200mm x 200mm, while industrial FDM printers can have a build volume of up to 1000mm x 1000mm x 1000mm.
Warping
Warping is one of the common issues that occur with the FDM process. It is caused by the uneven cooling of the material, which causes the corners of the object to lift up, resulting in a warped or distorted object. To prevent warping, it is essential to ensure that the build platform is level and that the material is being printed at the correct temperature.
Temperature & Build Speed
The temperature and build speed are also critical characteristics of FDM 3D printers. Different materials have different melting points, so it is essential to ensure that the printer is set to the correct temperature for the material being used. The build speed refers to the speed at which the printer can deposit the material. A faster build speed can lead to a quicker print time, but it can also result in a lower-quality print.
Layer Adhesion
Layer adhesion refers to how well the layers of the object are bonded together. Poor layer adhesion can result in a weak or brittle object. To ensure good layer adhesion, it is essential to print at the correct temperature and ensure that the layers are being deposited at the correct speed.
Support Structure
Support structures are used to support overhanging parts of the object that would otherwise droop or collapse during printing. The support structures are printed alongside the object and then removed after printing. Support structures can be generated automatically by the software or added manually by the user.
Infill & Shell Thickness
Infill refers to the amount of material that is printed inside the object. A higher infill percentage results in a stronger object, but it also takes longer to print. Shell thickness refers to the thickness of the outer walls of the object. A thicker shell can result in a stronger object, but it can also increase print time.
Layer Height
Layer height refers to the thickness of each layer that is printed. A thinner layer height can result in a higher quality print, but it also takes longer to print. A thicker layer height can result in a faster print time, but it may sacrifice quality.
What are the Differences Between Desktop FDM & Industrial FDM Printers?
Desktop FDM printers and industrial FDM printers are designed for different applications and users, and therefore they differ in several key aspects.
Build Volume: Industrial FDM printers have a much larger build volume than desktop FDM printers, allowing for the printing of larger objects.
Print Speed: Industrial FDM printers have higher print speeds than desktop FDM printers, allowing for faster production of parts.
Resolution: Industrial FDM printers typically have higher resolution capabilities than desktop FDM printers, allowing for more precise and detailed prints.
Material Compatibility: Industrial FDM printers are often designed to handle a wider range of materials, including high-performance engineering plastics, while desktop FDM printers are limited to mostly consumer-grade materials.
Cost: Industrial FDM printers are significantly more expensive than desktop FDM printers, reflecting their higher capabilities and capacity.
Complexity: Industrial FDM printers often have additional features such as multiple extruders, automated bed leveling, and other features that enable them to handle complex printing tasks, while desktop FDM printers are simpler and often require more manual intervention.
Quality: Industrial FDM printers can produce parts with a higher quality finish and consistency, while desktop FDM printers often struggle to produce high-quality parts on a consistent basis.
While desktop FDM printers are suitable for small-scale production and hobbyist use, industrial FDM printers are designed for larger production runs, higher print quality, and a wider range of materials.
Applications & Usages of Fused Deposition Modeling
FDM process is a versatile 3D printing technology that has a wide range of applications across various industries. Here are some of the most common applications and usages of FDM:
Prototyping: FDM is widely used for prototyping new products and parts. This is because FDM printers are capable of producing parts with high accuracy, speed, and low cost.
Tooling: The FDM process can be used to produce custom jigs, fixtures, and tooling for manufacturing processes. FDM-produced tooling is often much faster and more cost effective than traditional manufacturing methods.
Manufacturing: FDM is increasingly being used in small-scale manufacturing applications, such as producing custom parts, components, and tools.
Architecture: FDM process is used in the architectural industry for creating models and prototypes of buildings, structures, and other designs.
Medical: FDM is used to create surgical guides, prosthetic parts, and other medical devices. FDM can use biocompatible materials for use in medical applications.
The FDM process is versatile and can be used in various industries and applications. From prototyping to manufacturing, education to entertainment, FDM provides a fast, accurate, and cost-effective solution for creating custom parts and designs.
What are the Advantages & Limitations of the FDM Process?
Advantages:
- FDM is one of the most affordable 3D printing processes.
- This allows for the creation of complex geometries and intricate designs.
- FDM is a fast and efficient process, allowing for quick prototyping and iteration.
- It allows for the use of a wide range of materials, including PLA, ABS, PETG, Nylon, and TPU.
Limitations:
- It has a lower resolution than other 3D printing processes, resulting in a rougher surface finish.
- Prone to warping and distortion, particularly when printing larger objects.
- FDM has limited strength and durability, particularly when compared to injection molding or CNC machining.
- Requires support structures for overhanging parts, which can be time-consuming to remove after printing.
Common Materials Used in FDM 3D Printing
PETG, PLA, ABS, PC (polycarbonate), Nylon, PEI, and TPU are some of the most commonly used materials in FDM 3D printing. PETG is a strong and flexible material, PLA is a biodegradable material that is easy to print, ABS is a strong and durable material that is commonly used in industrial applications, PC is a heat-resistant and strong material, Nylon is a strong and flexible material, PEI is a heat-resistant and strong material, and TPU is a flexible and elastic material that is commonly used for creating phone cases and other protective gear.
PETG (Polyethylene Terephthalate Glycol):
PETG is a popular material for FDM 3D printing due to its unique combination of properties. PETG is a thermoplastic polyester that is a copolymer of PET and glycol. Here are some of the main benefits and considerations when using PETG in FDM 3D printing:
Strength: PETG has high strength and toughness, making it suitable for applications that require durable and impact-resistant parts.
Flexibility: PETG is more flexible than materials like PLA and ABS, making it ideal for parts that need to bend or flex without breaking.
Heat resistance: PETG has good heat resistance, with a glass transition temperature of around 80-85°C. This makes it suitable for applications where parts will be exposed to high temperatures.
Chemical resistance: PETG is resistant to chemicals such as acids, bases, and alcohol, making it suitable for applications in harsh environments.
Transparency: PETG has excellent optical clarity, making it ideal for applications such as lighting fixtures and display cases.
PEI (Polyetherimide):
These are high-performance engineering thermoplastic material that is known for their strength, durability, and high-temperature resistance. It is used in the FDM process for creating parts that require high strength, durabilities, and heat resistance, such as aerospace and automotive parts, electrical components, and medical devices. PEI also has excellent chemical resistance and is commonly used in applications that require exposure to harsh chemicals or solvents.
PLA (Polylactic Acid):
PLA is one of the most commonly used materials in the FDM process. It is a biodegradable and sustainable thermoplastic material that is made from renewable resources such as corn starch or sugarcane.
PLA is easy to print with and provides a good surface finish and detail. It also has a low melting point and a wide processing temperature range, which makes it compatible with a variety of 3D printers.
Prototyping: PLA is often used for rapid prototyping because of its ease of use, low cost, and good surface finish. It can be printed quickly and accurately, allowing designers to iterate and test their designs before committing to more expensive production methods.
Hobbyist projects: PLA is also popular among hobbyists and makers who create decorative or functional objects such as toys, figurines, and household items. Its bright colors, ease of use, and biodegradability make it an attractive choice for DIY projects.
Architectural models: PLA is also used for creating architectural models and other models that require high detail and accuracy. Its ability to produce fine details and intricate designs makes it a good choice for these applications.
PLA is a versatile and widely used material in FDM 3D printing due to its ease of use, low cost, and biodegradability.
TPU (Thermoplastic Polyurethane):
It is a flexible and elastic material that is used in the FDM process for creating parts that require flexibility, such as phone cases, toys, and footwear. TPU is also known for its excellent abrasion resistance and chemical resistance, making it suitable for creating parts that will be exposed to harsh environments. TPU is more challenging to print with than other materials due to its flexible nature, but with proper settings and techniques, it can produce high-quality prints.
ABS (Acrylonitrile Butadiene Styrene):
It is another commonly used thermoplastic material in FDM process. It is a strong and durable material that is often used for creating functional parts and objects.
Functional parts: ABS is a strong and durable material that can withstand impact and high temperatures, making it ideal for creating functional parts such as gears, bearings, and mechanical components.
Automotive and aerospace parts: ABS is often used in the automotive and aerospace industries for creating parts that require high strength, durability, and heat resistance.
Electrical enclosures: ABS is a good insulator and is often used for creating electrical enclosures and housings for electronic devices.
Toys and consumer goods: ABS is a popular material for creating toys and consumer goods because of its durability and ability to produce bright colors and glossy finishes.
Injection molding prototypes: ABS can be used to create prototypes for injection molding, which is a common manufacturing process for creating plastic parts in large volumes.
PC (Polycarbonate):
It is a high-performance thermoplastic material that is known for its strength, toughness, high-temperature resistance, and clarity. It is used in FDM 3D printing for creating parts that require high strength, toughness, high-temperature resistance, and optical or electrical properties.
Best Practices With FDM Printers
- Level the build platform before printing to prevent warping.
- Use the correct temperature and print speed for the material being used.
- Use support structures for overhanging parts.
- Use infill and shell thickness settings to balance print time and strength.
- Use a thin layer height for higher-quality prints.
Conclusion
Fused Deposition Modeling is an essential 3D printing process that is used across a wide range of industries and applications. Despite its limitations, the FDM process remains one of the most affordable and accessible 3D printing processes, making it an ideal choice for small businesses, hobbyists, and educators. By understanding the characteristics of FDM 3D printers, the differences between desktop and industrial FDM printers, the advantages and limitations of the FDM process, and the common materials used, users can optimize their prints and achieve high-quality results. Best practices with FDM printers include leveling the build platform, using the correct temperature and print speed, using support structures for overhanging parts, and using infill and shell thickness settings to balance print time and strength. With the continued advancement of FDM technology and materials, it is likely that the FDM process will continue to be an essential process for 3D printing in the future.
