FDM or the Fused Deposition Modeling is the layer additive manufacturing process that uses thermoplastic which is called as a filament FDM 3D printing is used to produce prototype, along with the functional parts. Nowadays FDM is actively used by hobbyists. FDM printing is known for producing detailed prints, with an excellent strength-to-weight ratio.
Components Of FDM Printer
Filament – It is a thermoplastic material.
Spool Holder– It is a stand for holding the filament, if a printer doesn’t come with the spool holder one can easily print it.
Print Bed – This is where the filament gets extruded. It can be heated or non-heated. It is made from different materials according to usage and come in various shapes. In some latest printer there’s a system that is used for the levelling of the print bed.
Display unit – Display unit exhibits the print status, temperature, axis and for gives command to the 3D printer.
Controller board – This is the brain of the printer. It basically works around the core operations of the printer.
Stepper motor – All the mechanical movement of the printer is done by a stepper motor
Body Frame – It assembles all the parts of the 3D printer together.
Extruder and hotend – It is used to heat the filament to its melting point and assists maintain a certain temperature. It pushes out the filament.
Nozzle – It is made from varying materials, brass nozzle amongst it is most commonly used. Nozzle should be replaced regularly for better print quality.
Cooling Fan – It cools the extruded filament.
Working of FDM printer
The FDM printer begins by slicing the CAD data, layer by layer with the help of a slicer and converts the CAD file to a format that can be interpreted by the printer. This is usually done in the STL or OBJ format.
The filament is kept on the spool holder, end of the filament goes inside the extruder which then pulls it. After receiving the command, the process of extrusion starts. Hotend of the extruder heats up the filament to its melting point. This process is somewhat similar to the hot glue gun.
Now, the extruder pushes out the heated filament on the print bed, in a layer-by-layer manner, fusing the filament, depositing it one over the other and forming a complete 3D printed object. The movement of the extruder is managed by the stepper motor. In some arrangements the extruder moves only along the X and Y axis and movement along the Z-axis is done by the print bed. However, nowadays it is the extruder that moves on all X, Y, and Z-axis while the print bed remains relatively fixed.
After every print layer, cooling fan is used so that it cools down the extruded layer and solidifies it. It should be ensured that the cooling fans blow evenly along the print lines. After a successful print, the printed object is removed from the printer bed and goes through a finishing process.
Word of Caution
Never touch the nozzle directly by your hand, it is extremely heated and can result in severe burns.
Materials used for FDM printing
The material used for FDM Printing is called a filament, made from thermoplastic material. Filament usually comes in two compatible sizes, 1.75mm and 2.85mm, which is it’s thickness. The filament is sold according to its weight as well as length, but most people buy it according to the weight of the spool. The filament is sometimes biodegradable also.
There are different types of filament each has its own pros and cons. A few of them are:-
Benefits of FDM Printer
- FDM 3D Printer reduces the time of making prototypes and functional models. Before the printing process, models are designed on the computer using various CAD software on which detailing is done. Since the process is done on a computer it saves time.
- FDM materials can be welded together. Hence the complete print can be divided into small parts which are each printed separately and after the completion, they can be joined together as a whole.
- Due to the widespread availability of FDM printers and filaments this technology has now become cheap and is now used by hobbies for designing and modeling.
- It saves the wastage of the material.
- FDM printer has increased the accuracy of the products as the prints are commanded by the computer It has also improved its design.
- Filaments are made from a range of materials as per the requirement, ranging from flexible, metal, and nylon.
Limitation of FDM Printing
- Parts produced from the FDM printer require post-processing since it is produced layer by layer so the surface of the print has to be leveled it is done through various processes like sanding and vapor smoothing.
- Printed parts can only be used for prototyping. They can not be used for heavy load or functional parts for a long time as it wears out after use.
- 3D printed parts are weak along the print lines.
History of FDM printing
Japanese inventor, Hideo Kodama in 1981, created a product that used UV lights to harden the polymers and create solid objects, this created the earliest forms of 3D printing and the stepping stone to stereolithography (SLA). Not much later, the Fused Deposition Modeling (FDM), developed by Scott Crump, became the most common form of 3D printing. This form of printing came to be known as desktop 3D printers. In order to form an object, the printer heats up a cable of thermoplastic into liquid form and extrudes it layer by layer. It wouldn’t be wrong to say that 3D printing has changed and improved over the past thirty years. SLA, SLS, and FDM vividly portray the history of 3D printing, along with how it became a vital tool for manufacturing.