Fused Deposition Modeling (FDM): Everything You Need to Know

Source: 3dnatives.com

Fused deposition modeling or FDM is the main and most well-known technology in 3D printing, also known as FFF for short. S. Scott Crump developed FDM in the late 1980s and Stratasys commercialized it in 1990. Another important year in the development of FDM was 2005, when Professor Adrian Bowyer started the RepRap project, the global movement behind open-source, self-replicating 3D printers of the same name.

How to 3D Print with Fused Deposition Modeling

FDM is often considered the simplest 3D printing technology. The fundamental elements for FDM are essentially 3: a print bed on which the part is printed; a spool of filament that acts as the printing material and an extrusion head, also called an extruder. In short, the filament is melted by the printer's extruder, which deposits the material layer by layer on the bed.

It all starts with designing the object you want to 3D print using 3D CAD software (such as SolidWorks, TinkerCAD or SelfCAD). Once designed, the 3D model (often in . STL format ) is divided into several layers using a Slicer (such as Cura or Repetier) before choosing the printing parameters.

The 3D printer starts printing when the machine has reached the optimal temperature, usually around 200°C (392°F), necessary to melt the material. The most commonly used materials in fused deposition modeling are PLA (polylactic acid) and ABS (acrylonitrile butadiene styrene).

Once the temperature is reached, the filament with a diameter of 1.75 mm or 2.85 mm is extruded onto the bed through a nozzle. This moves by moving on the X, Y and Z axes. The bed lowers allowing the addition of one layer on top of another until the 3D printed object is ready.

During printing, it may be useful to have supports that hold the model up, preventing it from collapsing. These supports can be made of the same material as the object, a water-soluble material, or limonene. Some more complex 3D printers can come with multiple extruders to combine different colors and support materials.

Materials Compatible with FDM 3D Printers

FDM printers are compatible with a wide range of thermoplastic polymers such as PLA And ABS, but also polycarbonates (PET, PS, ASA, PVA, Nylon), composite filaments based on metal, stone, wood and much more. These compounds often have interesting mechanical properties such as conductivity, biocompatibility or thermoresistance. By replacing the extruder of a 3D printer with a syringe system, it is also possible to create parts with clay or even edible materials such as chocolate! The price of these materials varies, to give you an idea 1 kg of PLA filament is sold at around €35.

There are some promising new projects that attempt to provide multi-colored parts to combine thousands of colors. These include, among others, the Da Vinci Color from XYZprinting. These projects combine or color the filaments to achieve the full CMYK color gamut with over 10 million combinations available.

FDM 3D Printing Prices, Performance and Specifications

The price of the FDM 3D printers varies considerably. The cheapest, modular RepRap type starts at €300. The price grows exponentially up to €2,500 for mid-range models and up to €10,000 for professional machines. The main players on the market are the historic manufacturer Stratasys, and brands such as MakerBot (acquired by Stratasys in 2013), Ultimaker and Prusa.

Although some 3D printers can print thin layers of up to 50 microns thick, FDM print quality is not the best when compared to other technologies, such as stereolithography for example. The volume that 3D printers can print is usually 12x12x12 cm although XL printers can print up to 30x30x30 cm and extreme printers can print even more than a cubic meter.

There are different types of FDM 3D printers depending on the mechanism used. Cartesian 3D printers use X, Y, and Z axis coordinates, while polar models use polar coordinates (angle and length). Delta printers are also available with a vertical structure, a round print bed, and a fixed three-arm extruder. More recently, robotic arms with multiple rotation axes have been introduced to the market for FDM 3D printers.

Fused Deposition Modeling (FDM) in a Nutshell

Low cost, ease of management and speed of execution make FDM printing a popular technique. The sectors in which this technology finds application are diverse: aerospace, automotive, architectural, medical, artistic and others. Its main use is in rapid prototyping or validation of visual models or functional parts. Filament extrusion can be easily used in small-scale production with its vast catalog of thermoplastic materials.