3D printing is the process of creating an object by depositing the material layer by layer. This deposition of material can be done through various processes. Of these various technologies, 5 technologies became very popular. These are FDM, SLA, SLS, PJP, DLP. In this article we shall discuss more about FDM and SLA technologies and also the difference between these two technologies.

Fused Deposition Modeling (FDM)

FDM stands for fused deposition modeling. In FDM technology, material is deposited in layers to create a 3D printed object. A plastic filament is fed through hot extrusion head. In the extrusion head, the filament gets melted. This melted filament will be deposited by drawing plastic lines on top of previous layers. FDM printing is one of the most widely used forms of 3D printing as of date. This can be primarily attributed to the fact that the FDM printer comes at a low price point. The bonding force of FDM type printers isn’t very strong. This leads to layer separation of resulting prints compromising on the resolution and surface smoothness. Also, if the diameter of extruded plastic line gets smaller, the printing speed will come down drastically.

Here is a beautiful time lapse video on give an overview on FDM technology

Advantages of FDM technology

Low cost, easy availability, low cost maintenance.

Disadvantages of FDM technology

Mechanical Strength, Surface Finish

Best Use Case

FDM can be used for one-off, single use low cost, non structural parts

Stereolithography (SLA)

SLA stands for stereolithography. In Stereolithography, UV light pattern is used to cure full layer of resin. The photo polymers are cured layer by layer to create the final object. SLA produces higher resolution objects and is more accurate than FDM as the resolution is primarily determined from the optical spot size which is very small. Also, much less force is applied in SLA than in FDM during layer formation and so the surface finish is much smoother and objects printed using SLA look much more professional than FDM printed objects.

Below video explains SLA technology in detail

Advantages of SLA technology

Good quality finish, mechanical strength

Disadvantages of SLA technology

Expensive when compared to FDM. As these parts are UV cured, long-term exposure to sunlight can reduce mechanical strength.

Best Use Case

SLA can be used when parts have intricate details or need a very smooth surface finish.