How Does a 3D Printer Work? [A Beginner-Friendly Guide]

A 3D printer is a device that brings three-dimensional designs to life. It has found its way into various industries due to its wide range of capabilities.

Among these industries are aerospace, automotive, and healthcare, which are crucial to creativity and technological advancement. 

The global market for 3D printers is expected to reach $56.48 billion in 2030. It has indeed come a long way since its inception.

While 3D printers have been around for a while, many people still need to learn how they operate, and this article will show you how. 

Step-by-Step Guide On How 3D Printers Work

Unlike standard printers that use ink or toner, 3D printers use a type of plastic called a filament.  

The 3D printer takes the filament and heats it until it becomes soft and flexible. It then squeezes out the melted filament through a tiny nozzle.

The nozzle moves around, prints the first layer, waits for it to dry, and prints the next layer on top. As the printer continues adding layers, the object begins to take shape.

There’s more to it than just layers; learn more about the details below.

Step 1: Designing The 3D Model

3D modeling is the process of developing three-dimensional models of objects using computer-based 3D modeling software such as SketchUp.

Modeling software allows artists, engineers, and designers to determine the design’s size, form, and texture. The procedure uses points, lines, polygons, and other elements only available in 3D modeling software.

There are three main techniques in 3D modeling. Look at each of them below.

• Solid Modeling—Mechanical and industrial designers mostly use this rigid technique. This design approach works with programs like SelfCAD, Fusion 360, Solidworks, FreeCAD, Catia, CREO, Rhino, and AutoCAD.

• Surface Modeling—Typically employed in artistic fields such as animation and 3D compositing. CATIA, Blender, and Rhinoceros are usually utilized in this category.

• Organic Modeling—Mostly used for designs with intricate details like sculptures and characters. SelfCAD, ZBrush, and Autodesk Mudbox are the most widely used software.

Once the 3D design is finished, it is saved as either a stereolithography file (STL) or an additive manufacturing file (AMF).

If you are unfamiliar with the software listed above, here are some websites to obtain free and paid models:

• Myminifactory
• Thingiverse
• Cults3d
• GrabCAD
• Free3D
• Pinshape
• STL finder
• SketchFab
• Thingiverse

A tiny nozzle moves around to print the design, but does it move independently? Venture into the next step to know the answer.

Step 2: Slicing The Model Into Layers 

A slicer is an intermediary between a 3D CAD model and a 3D printer. It converts your 3D model into a language your 3D printer can understand—the G-code. 

The G-code file provides instructions such as how the printer should move, what speed to utilize, and the size of the 3D printer filament to extrude.

There are various slicing programs that you can use, but the most popular software that is suitable for beginners is Cura.

With the digital blueprint and layers precisely sliced, it's time to layer your creation. 

The following step will introduce you to the various technologies used in 3D printing.

Step 3: 3D Printing the Model      

After you've finished slicing, you can upload the slice file to the printer and watch your design come to life. Recognize when they are most advantageous to designers, engineers, and product developers.

Take a look at some of the most common plastic 3D printing procedures. 

1. Material Extrusion

This 3D printing technology, often known as Fused Filament Fabrication (FFF), is a popular procedure for hobbyist-level 3D printing.

It works by heating a thermoplastic filament to its melting point and then squeezing it out layer by layer.

Another process that uses this technique is Fused Deposition Modeling (FDM). This approach, however, has dimensional accuracy constraints.

FDM is commonly used for electrical wiring, construction and fit testing, jigs and fixtures, and investment casting patterns. 

2. Photopolymerization 

Photopolymerization is a technique that uses photopolymer resins to build detailed and accurate 3D objects layer by layer.

Each layer is subjected to a UV light source, such as a laser or projector, which cures the liquid resin selectively, hardening it and forming a solid connection between the layers.

The following are the most popular photopolymerization 3D printing technologies:

• Stereolithography (SLA)—also referred to as SL, optical fabrication, photo-solidification, or resin printing.

During the procedure, a concentrated ultraviolet or laser beam is directed onto the surface of a vat (or tank) containing a liquid photopolymer.

Each layer of the desired 3D item is created by cross-linking or decomposing a polymer.

• Digital Light Processing (DLP)—A method that utilizes an optical semiconductor called a Digital Micromirror Device (DMD) to project images with remarkable precision and clarity. 

The DMD chip consists of thousands of microscopic mirrors that tilt rapidly to reflect light and create a projected image. 

Each mirror on the chip corresponds to a pixel on the screen, resulting in highly detailed visuals.

• Continuous Liquid Interface Production (CLIP)—Unlike conventional 3D printing methods that build objects layer by layer, CLIP utilizes a photochemical process to create objects from a pool of liquid resin.

During the process, a light projector emits specific patterns of UV light, selectively curing the resin. This eliminates the need for layer-by-layer fabrication, resulting in significantly faster production times.

It's said to be a hundred times faster than regular 3D printing.

• Daylight Polymer Printing (DPP)—A manufacturing technique that employs LCD (Liquid Crystal Display) to cure the polymer rather than a laser or a projector.

It makes use of unmodified LCD screens as well as a specially developed daylight polymer.

Photopolymerization allows for the creation of complex geometries and intricate internal structures that would be challenging or impossible to achieve through traditional manufacturing methods.

The technique is commonly employed in the medical field for anatomical models and microfluidics, dental applications, adornments, and amplifiers.

3. Binder Jetting

This method works by depositing a thin layer of powdered material onto the build platform, followed by drops of adhesive deposited by a print head to bind the particles together. 

Metals, sands, and ceramics are among the materials that may be used in the process.

Binder jetting is ideal for applications requiring a high level of aesthetics and shape, such as architectural models, packaging, toys, and figurines, but is often unsuitable for functional purposes because of the brittle nature of the pieces.

4. Direct Energy Deposition

A process that uses focused thermal energy to fuse wire or powder material as it is deposited, such as an electric arc, laser, or electron beam.

DEP is a complicated printing procedure typically used to repair high-end components and functional prototypes.

5. Material Jetting

This method deposits layers of liquid material on print heads. Layers are supported by structures built of water-soluble material that may be washed away after the build.

It is one of the most expensive methods of 3D printing, even though the pieces are brittle and will degrade over time.

The most common applications of the material jetting process are the following:

• Aesthetic prototypes
• Injection mold prototypes
• Elaborate medical models
• Design presentations  

6. Sheet Lamination

This method creates 3D objects by stacking skinny metal sheets. Although the process could be more precise, it does produce extraordinarily rapid and cost-effective products.

As a result, there are few options for functional applications. The following are some of the most common sheet lamination applications:

• Non-functional prototypes
• Design viability assessment
• Presentation models
• Multi-color prints
• Casting molds

7. Powder Bed Fusion 

PBF is a popular additive manufacturing technology due to its capacity to produce complicated geometries with precision.

A thin layer of powder is spread over a build platform, followed by applying the laser to fuse the particles based on a digital model's specifications.

Among the several Powder Bed Fusion procedures are:

• Selective Laser Sintering (SLS)—The process uses a high-powered laser to selectively scan and fuse the powdered material into the required form. 
• Selective Laser Melting (SLM)—SLM, also known as Direct Metal Laser Sintering (DMLS), uses the same technology as SLS. However, it is exclusively used to produce metal parts.
• Electron Beam Melting (EBM)—This process utilizes less energy, resulting in less residual stress and less deformation.
• Multi Jet Fusion (MJF)—This 3D printing process uses no laser. Instead, an inkjet array applies fusing and detailing chemicals and heats them into a solid layer.

PBF presents several applications, including jewelry, dental and medical prosthetics, prototypes, aerospace and defense, and motorsports.

Step 4: Post-Processing and Finishing

Post-processing comprises the removal of support structures, the sanding of rough edges, and the application of finishes such as painting or varnishing the 3D prints.

This last step in 3D printing enhances the aesthetics and functionality of the printed object.

3D Printing Materials

Materials used in 3D printing vary significantly, making it a viable alternative for various parts, from highly accurate aerospace and industrial machinery components to customized consumer goods.

Here are some materials you can choose from for your next project:

• Plastics—Frequently used in the 3D printing process. It is a versatile material for 3D-printed toys and household items.

• Powders—Modern 3D printers melt and layer powder to create the required thickness, texture, and patterns.

• Resins—Due to its low flexibility and strength, resin is rarely used in 3D printing.

• Metals—The second-most-popular material in 3D printing due to their ability to manufacture more robust and arguably more diverse everyday items.

• Carbon Fiber—Used as a top coat over plastic materials to strengthen the plastic.

• Graphite and Graphene—These are popular materials due to their strength, conductivity, and suitability for flexible device parts like touchscreens.

• Nitinol—A nickel-titanium alloy valued in 3D printing for its unique characteristics, such as pseudoelasticity and “shapememory," commonly used in medical implants.

Advantages And Disadvantages Of 3D Printing

3D printing opens up a world of possibilities that no other medium can match. Every primary industry has embraced the technology.

However, like any other technical innovation, it has advantages and disadvantages. 

Read on to find out about the pros and cons of 3D printing.

Advantages Of 3D Printing

3D printing offers several advantages, making it a highly favorable technology in various fields. 

Delve into these advantages and explore some of them in the following section.

• Environmentally Friendly—The 3D printing technology consumes less material, can reuse powders, and recycles the majority of plastic supports.
• Not Too Expensive—A hobbyist can score a 3D printer for between $300 and $500; used ones are even cheaper. And some materials can cost as little as $15 per kilogram.
• Reduced Material Waste—Additive manufacturing, like 3D printing, adds the material needed for the part and supports it during production, reducing waste.
• Medical Application—Through unique, patient-matched implants, prostheses, and organ bioprinting, 3D printing has improved individualized medical care.
• Fast Production - 3D printing can manufacture complex items faster than molding or milling in hours.

• Robust And Lightweight Elements—These are crucial in industries like automotive and aerospace, where weight could be an issue.
• Adaptability In Design—3D printing can produce more complicated patterns than traditional manufacturing procedures. The process removes design constraints from older techniques.

Disadvantages Of 3D Printing

Despite its numerous advantages, it is also essential to consider the potential drawbacks of 3D printing technology.

Explore some of the disadvantages of 3D printing below.

• Post-Processing—To get the desired polish, most 3D-printed components must be cleaned to remove the support material.
• Resource Availability—3D printing has a limited material selection, such as food-safe materials.
• Structural Quality—FDM and SLS are anisotropic components. This means the parts’ pieces perform differently depending on the load direction. Z-axis sections are usually the weakest.
• Reduced Employment in Manufacturing Industries—One person can often manage multiple 3D printers, reducing the need for further help.

• Inaccurate Designs—During printing, some parts may warp.
• Counterfeits and Copyright Issues—Many designs are available for free download online, which is unfair to the designers who created them. 
• Limits on Building Size—The present print chambers of 3D printers are pretty small, limiting the size of the printable parts.

Here is a rundown of the benefits and drawbacks of 3D printing:

Wrap-Up

The rapid prototyping capabilities of 3D printing allow for quick iterations and cost-effective product development.

Along with its ability to create unique objects tailored to individual needs, it continues to shape industries and drive innovation.

As technological advances are made daily, the possibilities with 3D printers are endless, so keep an eye out.