Prototype Mechanics: Fused Deposition Modeling and its Advantages

Suganya Sukumar Apr 28, 2019
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Fused deposition modeling is a mechanical manufacturing technology and one of the important concepts in mechanical engineering. Let's learn about this process and its advantages in detail.
Fused Deposition Modeling (FDM) is basically a rapid prototyping technique and it is one of mechanical manufacturing technologies, in which the process of extrusion of thermoplastics is involved. This process is very similar to that of naming on a baked cake in which cream is compared to thermoplastic and cake is to a table.
The relative motion between table and extrusion metal can be made either by making the table to move or the molten metal to move. But one important thing is, the extrusion metal will always be in X-Y plane.
In this rapid prototyping technique, the first layer of metal which falls on the table will be at a higher temperature and the platform on which it falls will be at a lower temperature; this helps the molten metal to get hardened in quick time and second layer will be deposited on the first layer.

Parts of a FDM Machine

Raw material: The raw material mostly used in this process is generally thermoplastic filaments or beads. ABS (Acrylonitrile Butadiene Styrene) material, polyamide, polycarbonate, polyethylene, polypropylene, and investment casting wax are the raw materials that are used in the technique. Supporting materials are also used along with the main raw material.
Extrusion nozzle: This is an important part of the apparatus from which metal gets heated up and liquefied. The extrusion nozzle can be moved along the X-Y plane only.

Stepper motors: The stepper motor helps to move the nozzle according to the CAM (Computer-Aided Manufacturing) program code which defines the path of the motion of nozzle.
Nozzle tip: This nozzle tip is the last point from which hot thermoplastic will get deposited on the platform.

Drive wheels: The drive wheels will provide the required feed for the filaments so that it properly moves into the liquefier.
Liquefier: This part of the set up liquefies the thermoplastic filament to molten state, which is then deposited on the platform.

Platform: This is the base on which fused deposition model is produced.

Technical Specifications

  • Maximum Part Size : 36.00 x 24.00 x 36.00 (inches)
  • Pressure : 34487 Pa to 68974 Pa
  • Operating Temperature : 82°C to 85°C
  • Filament Type : Solid
  • Minimum Layer Thickness : 0.0050 inches

Software Function

Now you must be clear with, how the FDM machine is designed and the function of its parts. We will now learn how the software is processed to make the machine work efficiently. Generally, FDM process is done by feeding the desired inputs using two computers.
In one computer, the 3D model of the machine is made using software such as ProE, Rhino, Unigraphics, etc. While designing the 3D model, it is very important to set the software such that the material which is to be produced should be in solid form and not a hollow one.
The 3D model which we have designed in this computer, is stored in STL file format and it is transferred to another computer which is called FDM computer.
The numeric codes are programmed in the FDM computer, to assign the required measures of the machine parts like nozzle tip, etc. In the FDM computer, the parameters such as size, scale and orientation can be manipulated using CAM software tool.

Advantages of FDM Technique

  • The machine designed using FDM rapid prototyping, will be efficient as it is made with high resolution and accuracy.
  • The tensile strength of the machine which is produced, is high.
  • Large number of machines can be produced in less amount of time.
  • Multiple coloring for the model can be given using this technique.
  • This process is used for producing high heat withstanding machines.
FDM is an additive technique in which machine is produced layer by layer and then fused together. This technique is mostly applicable for building small machines because, it takes more time to build large machines, as the process is done layer by layer. FDM is a very efficient technique and is widely used in production and manufacturing sectors.