1. What is 3D printing?
3D printing is an additive manufacturing process of creating three-dimensional (3D) solid objects from a digital file. A three-dimensional solid object is created by adding successive layers of material on top of each other. Each layer can be seen as a thin and horizontal cross-section of the eventual object. 3D printing allows you to produce complex shapes using less material and without the limitations of traditional manufacturing methods.
Example: Think of a bird building a Nest. It collects twigs and adds it into the desired position one by one. The bird manufactures a house layer by layer. In a similar manner, a 3D printer builds a particular object by depositing material at specific coordinates layer by layer.
2. The 3D printing process
It all begins with a 3D model. 3D printing begins by designing a 3D object in Computer-Aided Design (CAD) software such as Sketchup, Fusion 360, Solidworks, etc. There are many 3D modeling software available. But, industrial-grade software can cost thousands a year for a license. For beginners, we recommend Tinkercad. Tinkercad is a free-to-use tool that works on your web browser. Which means you don’t have to install it on your computer. From the CAD software, a . STL file is exported. The CAD design (.STL) acts as a “blueprint” of the model. Some 3D printers also support it.OBJ and . STEP file types, but.STL is the most common and most widely used. The.STL file is imported into 3D printing software like Ultimaker Cura and PrusaSlicer. The main role of this software (also known as slicers) is to convert or slice the 3D model into hundreds or thousands of layers and add specific instructions for the printer. These instructions include information such as X, Y, or Z coordinates, temperatures, print resolutions, infill, etc. Many of these slicing software is free to use. Simplify3D is one of the tops paid slicers available. The sliced file is then transferred to the 3D printer using wifi, USB, etc. and the 3D printer then follows the instructions to complete the model.
Here is a pictorial representation of the 3D printing process:
In order to get a good 3D print you need to design the model that is watertight and 3D print ready. You can access our guide on “How to make sure your 3D printing design file is correct - A guide”. Further, you have to make sure you put the correct slicing settings. Slicer settings need to be tweaked according to the 3D printer to get the best results. Needless to say the better the printer and raw materials the better the manufactured object.
Before you go about starting your 3D printing journey it is essential to understand the different types of 3D printing technologies. The 3D printing types abide by the above process, however, they work differently and might also use different materials (like resin and metals) from one another to output different characteristics in the end product.
3. What are the major 3D Printing Technologies?
FDM (Fused Deposition Modelling)
FDM is the most widely used 3D printing process. It is good for quick low cost prototyping and design verification.
How FDM printing works: FDM uses a continuous wire (filament) of plastic (thermoplastic) material as input. This wire is heated by the printer at the print head to convert solid material into liquid. This liquid is deposited at specific coordinates where it cools and solidifies making the desired 3D object. This process is also called fused filament fabrication (FFF).
Here is a short video that shows how FDM technology works -
SLA is a form of 3D printing technology that converts liquid to solid. Unlike FDM where solid material is converted into liquid and resolidified. Here we start with liquid resin that solidifies when it comes in contact with ultraviolet (UV) light.
How SLA printing works: We start with a tank with a transparent bottom. Liquid resin is added to the tank. A light source like a projector is positioned under the tank which is used to shine light at specific coordinates where the part is to be solidified. A platform submerges into the resin tank from the top to such a height that the solid 3D object sticks to the platform. Once a layer is fully solidified the platform, where the solid object is attached, moves up for new liquid resin to take place. The process keeps repeating itself until the 3D object is completed.
DLP or Digital Light Processing
DLP is often used as a synonym to SLA technology as they both use resin and UV light to make 3D objects. The major difference between DLP and SLA is that DLP uses an LCD projector as the UV light source compared to SLA, which uses a UV Laser.
Here is a short video that shows how SLA technology works -