Introduction to the most commonly used 3D printing technology: FDM
Author: Aaron Chen Date Posted:30 July 2019
3D printing has been widely used by designers and engineers to create prototypes. It also became a standard process for producing consumer items.
There are many different 3D printing technologies that designers can use today. FDM or Fused Deposition Modelling is known to be the most popular one.
But what does fused deposition modelling really mean? How does it work? Here is a blog post about what you need to know about the most commonly used 3D printing technology – FDM.
Brief history of FDM
FDM was first developed in 1988 by S. Scott Crump (co-founder of Stratasys). Crump commercialized FDM in 1990 with Stratasys.
But in 2009, the first FDM patent had expired. This led the people to use this type of printing without paying to Stratasys. It also opens up commercial, DIY and open-source 3D printer applications.
Overview of FDM
Fused Deposition Modelling, also known as Fused Filament Fabrication (FFF) is one of the additive manufacturing processes where an object is created by selectively depositing melted materials layer by layer. It usually uses thermoplastic polymers that come in filament form.
Below is the basic design details/settings for FDM printers:
- Materials that can be used: Thermoplastics (PLA, ABS, PETG, PC, PEI etc.)
- Dimensional accuracy: ± 0.5% (lower limit ± 0.5 mm) for desktop
± 0.15% (lower limit ± 0.2 mm) for industrial
- Typical build size: 200 x 200 x 200 mm for desktop
1000 x 1000 x 1000 mm for industrial
- Common layer height: 50 to 400 microns
- Support: Not always required (dissolvable available)
Pros and Cons
A designer should have enough knowledge when it comes to the capabilities and limitations of FDM technology.
FDM offers several advantages to designers, engineers and hobbyists compared to other 3D printing technologies. However, it also a list of downsides. Listed below are the pros and cons of FDM printing.
- FDM is considered as the most cost-effective way to create custom thermoplastic parts and prototypes.
- There is a wide range of thermoplastic materials available nowadays. It can be used for both prototyping and non-commercial functional applications.
- FDM printer is simple to use which makes it ideal for beginners to start 3D printing.
- Due to the availability of the materials and the technology itself, lead time for FDM is relatively short.
- Compared to other 3D printing technologies, FDM is known to have the lowest dimensional accuracy and resolution. Hence, it is not ideal for 3D parts with complicated details and geometries.
- 3D parts that are printed with FDM tend to warp easily. This means that when the extruded material cools down during solidification, the dimensions of the 3D part decreases. However, warping can be prevented by closely monitoring the temperature of the FDM printer.
- Post-processing is highly required since parts may likely have visible layer lines.
- Because of the layer adhesion mechanism in FDM, parts can be anisotropic (a physical property which has a different value when measured in different directions).
How FDM works
Printing using FDM printers starts out with a CAD file. This CAD file should be converted to .stl format. Most FDM printers use two kinds of materials during printing. First is the modelling material which is basically the finished object. The other one is a type of support material which will serve as a scaffolding to support the object while printing.
During the printing process, plastic threads or filaments are used as modelling materials. The nozzle will melt these filaments and extrudes them onto a base or build platform. The nozzle and build platform are controlled by a computer which translates the data of an object into X, Y and Z coordinates. Then, it prepares the material for printing.
The extrusion nozzle will move horizontally and vertically to create a cross-section of the object. This is done repeatedly, layer by layer until a 3D part is formed.
Post-processing for FDM
3D parts that are printed with FDM printers generally have rough surface finish. Most of the time, it can be distracting since it is visible to the eye. With post-processing, you can easily get rid of these imperfections.
However, post-processing is not merely about aesthetics. It can also improve the feel, strength and other properties of a 3D part.
Some of the post-processing techniques that are used for FDM includes support removal, sanding, acetone smoothing, priming and painting, etc.
FDM technology has been widely used by designers and engineers today. It is used to produce prototypes and functional parts at a low cost. It is also commonly used by beginners because it is user-friendly and widely available.
If you are new with 3D printing, it would be a good idea to ask help from a professional to handle your 3D printing project. A 3D printing service company in Sydney can provide services such as 3D modelling, custom 3D printing, industrial 3D printing and many more.