FFF (FDM) 3D printing is the most commonly used method because of the simplicity, intuitiveness, easy-to-understand principles, and methods of use.
Depending on the printhead driving method, the types of FFF printers can be divided into Cartesian, Delta, Polar, etc.
In another blog, we introduced various 3D printing methods and discussed SLA, the first 3D printing technology.
In this article, we will take a brief look at the most popular types of 3D printers called Fused Filament Fabrication (FFF) or Fused Deposition Modeling (FDM).
FDM/FFF (Most commonly used 3D Printer)
The basic principle of FFF is simple. The extrusion nozzles (with thermoplastics) move horizontally and vertically on the build platform. The thermoplastic is heated to its melting point and then extruded in the XY plane to complete one layer. Once the layer is complete, the base is lowered to make room for the next plastic layer, and the cycle repeats.
This additive manufacturing method was developed in 1988, and commercialized by Stratasys in 1992 under the trademark FDM. When the patent expired in 2009, many individuals and companies participated in product development, which made it possible to supply cheaper printers and allowed new developments in technology. As an alternative to the trademark term FDM, the name FFF was also born. Currently, FFF-type printers are being used in a variety of ways, from entry-level models for hobbies to high-tech industries.
< Fused Filament Fabrication >
There are many different types of FFF printers, and today we will categorize FFF printers based on the way that the printhead moves. The two most popular types of printing systems are Cartesian and Delta, and new printing systems are constantly being developed.
< Types of FFF Printers >
Cartesian Printer (Rectilinear Printer)
Cartesian is the most commonly used method, and it is what comes to mind for many when discussing FFF printing. Based on a Cartesian coordinate system, this technology uses three axes: X, Y, and Z to determine the position and orientation of the printhead and bed. Most printers only move the head in the XY plane and the bed in the Z axis linearly, but some printers distribute the head and bed axes differently.
An advantage to this method is that it is possible to obtain uniform printing performance in the horizontal direction, and it is easy to understand and implement kinematically, so that it is consumer-friendly. The disadvantage is that the printhead part is quite heavy, so it is difficult to change direction immediately when in motion.
This method of 3D printer is being used in various ways, and new products are constantly appearing in the FDM 3D printing market. While the cartesian coordinates are the same, instead of moving the printhead linearly, the head is hinged on three arms attached to a vertical rail. And the three arms move at the same time to adjust the position of the printhead. As a result, the print head of a delta printer is much lighter than if it had to include a moving motor. This reduced weight reduces inertia when the head changes direction, allowing for a quick response while maintaining accuracy. Delta printers are good for tall objects, as they provide fine precision in the center of the plane. However, they are less precise on the outside, so it is difficult to print wide objects.
In addition to the two methods above, many new types of printers are being developed. As the name suggests, Polar 3D printers use polar coordinates to determine the position of the printhead by angle (θ), distance from axis (R), and height (Z) rather than X, Y, Z coordinates. In general, the bed rotates (θ) and the extruder moves in the R direction. Normally, the bed rotates (θ) and the extruder moves in the R direction to print, and the extruder moves in the Z axis after completing one layer. Although this method is still relatively slow and the quality is not stable, the printhead operation is simple, quiet and space-efficient, making it a promising technology.
When we think of a free-moving robotic arm, we usually think of assembling parts on an industrial production line, especially in a large automobile factory. Integrating 3D printheads into these multi-axis robotic arms enables larger, faster, and more flexible 3D printing. Large-scale projects such as mold making, art sculpting, architecture and furniture often use huge rolls of filament, but most use polymers in the form of pellets or chips. Attempts to apply a robotic arm to smaller FFF printers are common. The print quality is not yet as good as the Cartesian printer. But it is important to consider the advantage of high portability because the printing plate is not fixed. Development is expected in the near future.
So far, we have discussed the types of FFF printers, and categorized them by the printhead driving method.
It's always interesting to see how technology evolves and new technologies emerge.
Next time we will look at two similar, but different 3D printer methods, SLS and SLM.
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