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How 3d printing


How a 3D Printer Works and What It Is Used for

3D printing, also known as additive manufacturing, is defined as a process in which a digital file is used to create a three-dimensional solid object. In the 3D printing process, sequential layers of material are laid down by the ‘printer’ until object creation is completed. This article covers the working, software, and applications of 3D printing.

Table of Contents

  • What Is 3D Printing?
  • How Does 3D Printing Work?
  • Top 7 3D Printing Software
  • 3D Printing Applications

What Is 3D Printing?

3D printing, also known as additive manufacturing, is a process in which a digital file is used to create a three-dimensional solid object. In the 3D printing process, sequential layers of material are laid down by the ‘3D printer’ until object creation is completed.

3D-printed objects are created through an additive process, where the printer places layer after layer of material until the desired thing is ‘printed’. Each layer can be considered a finely sliced cross-section of the printed item. With 3D printing, users can produce complicated shapes without consuming as much material as traditional manufacturing methods require.

The operation style of 3D printing is the opposite of ‘subtractive manufacturing’, where the material is cut out or hollowed using equipment such as a milling machine. Conversely, additive manufacturing does not need a mold or material block to create physical objects. Instead, it stacks layers of material and fuses them together.

3D printing offers swift product creation, low expenses for the initial fixed infrastructure, and the ability to create complicated geometries using several material types, something traditional manufacturing solutions might not be capable of as efficiently.

Timeline of 3D printing

Generally associated with the Do It Yourself (DIY) culture of amateurs and hobbyists, 3D printing has grown to include commercial and industrial applications. For instance, engineers today often use 3D printers for prototyping and creating lightweight geometric objects.

The origins of 3D printing lie in ‘rapid prototyping’. When the base technology was first invented in the 1980s, the term was used to describe it because, at the time, 3D printing was only suitable for creating prototypes rather than production components. In fact, the original intent of its creation was simply to accelerate the development of new products through swift prototyping.

Interestingly, the technology did not garner much interest when it was first introduced. In 1981, Japan’s Hideo Kodama filed the first patent for a machine that leveraged UV light for curing photopolymers. Three years later, French inventors Olivier de Witte, Jean Claude André, and Alain Le Mehaute jointly filed a patent for a similar technology. Both patents were abandoned, with General Electric saying the ‘latter lacked notable business potential’.

It was in 1984 that American inventor Charles Hull filed a patent for an ‘Apparatus for Production of Three-Dimensional Objects by Stereolithography’. He invented the STL file and founded 3D Systems three years later, in 1987.

Within the same decade, significant strides were made in the US 3D printing space, with patents filed for selective laser sintering (SLS) and fused deposition modeling (FDM). Desktop Manufacturing (DTM) Corp. and Stratasys were pioneering companies in the 3D printing space, founded around the same time.

After that, the industry transformed as rapid commercialization took hold of it. The first ‘3D printers’ were large and cost-intensive, with their makers competing to land contracts for industrial prototyping with large-scale automotive, consumer goods, health products, and aerospace manufacturers.

By 1987, 3D Systems had introduced the first commercial-grade SLA printer; in 1992, Stratasys and DTM released the first commercial FDM and SLS printers, respectively. The first metal 3D printer was introduced in 1994 by Electro Optical Systems (EOS), a German enterprise.

By the dawn of the new millennium, companies in the 3D printing space were competing fiercely for profits. Progress in materials science and the lapse of numerous patents increased the affordability of 3D printing.

Soon, thanks to the strides made in the 3D printing space, manufacturing processes were not exclusively owned by enterprises backed by heavy machinery and capital. Today, 3D printing has transformed into a cutting-edge solution for creating many different types of production components.

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How Does 3D Printing Work?

The ISO/ASTM 52900, related to the general principles and terminologies in additive manufacturing, categorizes 3D printing processes into seven distinct groups. Each type of 3D printing works a little differently.

The time taken to print a 3D object depends on the type of printing, the output size, the type of material, the desired quality, and the setup configuration. 3D printing can take anywhere from a few minutes to a few days.

The different types of 3D printing are:

1.

Powder bed fusion

In powder bed fusion (PBF), thermal energy, in the form of an electron beam or laser, selectively fuses specific areas of a powder bed to create layers. These layers are built on one another until a part is made.

PBF may include sintering or melting processes; however, the primary operation method remains the same. First, a recoating roller or blade places a fine layer of powder on the build platform. Next, the surface of the powder bed is scanned using a heat source. This source selectively increases particle temperature to bind specific areas.

Once the heat source scans a cross-section or layer, the platform descends to let the process be repeated for the next layer. The final output is a volume with fused parts, with the surrounding powder remaining unaffected. The platform then ascends to allow retrieval of the completed build. Powder bed fusion includes several standard printing methods, such as selective laser sintering (SLS) and direct metal laser sintering (DMLS).

SLS is regularly leveraged for manufacturing polymer parts for prototypes and functional components. SLS printing takes place with the powder bed as the sole support structure. The lack of additional support structures allows for the creation of complex geometries. However, produced parts often feature inner porosity and a grainy surface and generally require post-processing.

SLS is similar to selective laser melting (SLM), electron beam powder bed fusion (EBPBF), and direct metal laser sintering (DMLS). However, these processes are used for creating metal parts and rely on a laser for fusing powder particles, one layer at a time.

DMLS increases the temperature of the particles only up to the point of fusion, whereby they combine at a molecular level. On the other hand, SLM completely melts metal particles. Both these techniques are heat-intensive and thus require support structures. Once the process ends, the support structures are removed using CNC machining or manually. Parts are then thermally treated to address residual stresses during post-processing.

These metal 3D printing techniques create components with high-quality physical properties, sometimes even more robust than the base metal used. The surface finish is often excellent as well. In terms of material, these techniques can process metal superalloys and ceramics that can be hard to use in other processes. However, both DMLS and SLM are cost-intensive, and the system’s volume constrains the output size.

2. VAT photopolymerization

VAT photopolymerization can be split into two methodologies: digital light processing (DLP) and stereolithography (SLA). Both these processes create components one layer at a time by using a light source to selectively cure liquid material (usually resin) stored in a vat.

DLP works by ‘flashing’ an image of each complete layer onto the surface of the liquid in the vat. On the other hand, SLA relies on a single-point UV source or laser to cure the liquid. Excess resin has to be cleaned off the output once printing is completed, after which the item must be exposed to light to improve its strength further. Support structures, if any, will need to be removed post-processing, and one can further process the part to create a higher quality finish.

These methods are best-suited for output that requires high-level dimensional accuracy, as they can create intricately detailed items with an excellent finish. DLP and SLA are, therefore, well-suited for the production of prototypes.

However, these methods’ output is often brittle, making them less suited for functional prototypes. These parts’ color and mechanical properties are also likely to degrade in the sun’s UV light, making them unsuitable for outdoor use. Finally, support structures are often required and might leave blemishes, which one can remove through post-processing.

3. Binder jetting

Binder jetting works by depositing a fine layer of powdered material, such as polymer sand, ceramic, or metal, onto the build platform. After this, a print head deposits adhesive drops to bind these particles. The part is hence built layer by layer.

Metal parts must be thermally sintered or infiltrated with a metal that has a low melting point, such as bronze. Parts made of ceramic or full-color polymer can be saturated using a cyanoacrylate adhesive. Post-processing is generally required to finish the output.

Binder jetting has numerous applications, including large-scale ceramic molds, full-color prototypes, and 3D metal printing.

4. Material jetting

Material jetting is conceptually similar to inkjet printing. However, instead of inserting ink on paper, it uses one or more print heads to deposit layers of liquid material. Each layer is cured before the next layer is produced. While material jetting relies on support structures, they can be created using a water-soluble substance that is washable after the building is completed.

This highly precise process is well-suited for creating full-color parts using different material types. However, it is cost-intensive, and the output tends to be brittle and degradable.

5. Fused deposition modeling

In fused deposition modeling (FDM), a heated nozzle is used to feed a filament spool to an extrusion head. The extrusion head increases the temperature of the material, softening it before placing it in predetermined areas to cool. Once a material layer is created, the build platform descends and prepares for the next layer to be placed.

This process, also known as material extrusion, features low lead times and is cost-effective. However, its dimensional accuracy is low, and a smooth finish often requires post-processing. The output is also not well-suited for critical applications as it tends to be anisotropic, i.e., weaker in one direction.

6. Sheet lamination

Sheet lamination can be further classified into two technologies: ultrasonic additive manufacturing (UAM) and laminated object manufacturing (LOM). UAM has a low energy and temperature requirement and works by joining thin metal sheets using ultrasonic welding. It works with several metals, including stainless steel, titanium, and aluminum. On the other hand, LOM places layers of material and adhesive alternatively to create the final output.

7. Direct energy deposition

This technique uses a laser, electric arc, electron beam, or another form of focused thermal energy to fuse powder or wire feedstock as it is placed. The process takes place horizontally to create layers, which are then stacked vertically for part creation. It is suited for different material types, including ceramics, polymers, and metals.

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Top 7 3D Printing Software

The 3D printing space is heavily software-dependent, with programs required for everything from designing the output and slicing it into G-code to controlling the 3D printer. Let’s check out the top 3D printing software across applications.

1. MatterControl 2.0

This solution by MatterHackers is an all-in-one printer host, slicer, and CAD software for desktops. Users can create new models in the CAD section and slice them. Once the model is ready to print, MatterControl 2.0 can be used to directly monitor and control printing via a USB connection or over a Wi-Fi module.

The software features an intuitive interface and allows users to explore a collection of geometric primitives that users can import into the print. These primitives can be dragged into position on the standard triangle language (STL) file to be printed and designated as support structures.

MatterControl also gives users access to advanced print configurations, making it ideal for end-to-end design, support preparation, slicing, and control. Enterprise users can upgrade to MatterControl Pro for even more valuable features.

2. Tinkercad

This free, browser-based solution allows users to design printable 3D models and provides a starting place for practicing solid modeling. Its easy-to-use block-building feature enables users to form models using basic shapes.

Tinkercad has numerous guides and tutorials to help users create the desired designs, which can then be exported or shared easily. Its library gives users access to millions of files, allowing them to find and modify the required shape. Finally, it features direct integration with third-party printing services.

3. Blender

This free, open-source tool is well-suited for both newbies and advanced users. It is feature-rich and can be used for 3D modeling and sculpting, as well as for animation, rendering, simulation, video editing, and motion tracking. However, it has a steep learning curve.

4. UVTools

This open-source solution is a comprehensive resin printing suite, an excellent file viewer, and optimized for layer repair and manipulation for masked SLA. It is compatible with PrusaSlicer, giving users access to numerous third-party MSLA printer profiles.

Twin-stage motor control (TSMC) is a crucial feature of UVTools, enabling tiered print speeds for different movement parts for each layer. This reduces print time and boosts the likelihood of print success.

Finally, UVTools allows users to create a custom resin layer cure time calibration print for testing new resins and setting the appropriate configuration for different layer heights.

5. WebPrinter

This browser-based solution can be used to preview G-code without having to open the file in a full-capability slicer. Users simply need to upload the G-code file, and WebPrinter will show the tool pathing that the file will transmit to the 3D printer. It is a fast and simple method to view a potential 3D print output.

6. Ultimaker Cura

This open-source slicer is compatible with most modern 3D printers. Cura is well-suited for beginners as it is easy to use, swift, and intuitive. On the other hand, advanced users can leverage it to access 200 settings for refining prints.

7. Simplify3D

Simplify3D is a powerful slicing tool for enhancing 3D print quality. It slices CAD into layers, corrects model issues, and showcases a user preview of the final output. Its premium features are handy for enterprise heavy-use 3D printers.

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3D Printing Applications

Although 3D printing is not a recent invention, it has gained immense popularity in recent times across industries due to its newfound simplicity, efficiency, and cost-effectiveness.

The top applications of 3D printing are:

1. Construction

Construction is one of the significant applications of 3D printing. Concrete 3D printing has been explored since the 1990s as researchers sought a faster and cheaper way to construct structures. Specific applications of 3D printing in construction include additive welding, powder bonding (reactive bond, polymer bond, sintering), and extrusion (foam, wax, cement/concrete, polymers).

Today, large-scale 3D printers designed to print concrete are used to pour foundations and erect site walls. They are also capable of printing modular concrete sections for onsite assembly. These solutions allow for higher accuracy, more complexity, faster construction, and improved functional integration while lowering labor costs and minimizing waste.

In 2016, the first pedestrian bridge (12 meters long, 1.75 meters wide) was 3D printed in Spain using micro-reinforced concrete. A year later, the first fully 3D-printed residence was built in Russia. 600 wall elements were 3D-printed and assembled, after which, the roof and interiors were created for a total area of nearly 300 sq meters.

3D printing is also helpful in producing architectural-scale models. It is even being explored as a solution for constructing extraterrestrial habitats on the Moon or Mars, should the need ever arise.

2. Prototyping and manufacturing

In the case of traditional injection-molded prototyping, it can take weeks to produce a single mold that would cost up to hundreds of thousands of dollars. As established earlier in the article, the original purpose of 3D printing was faster and more efficient prototyping.

3D printing technology minimizes lead times in manufacturing, enabling prototyping to be completed within a few hours and at a small percentage of traditional costs. This makes it especially ideal for projects where users must upgrade the design with every iteration.

3D printing is also suitable for manufacturing products that do not need to be mass-produced or are usually customized. SLS and DMLS are used in the rapid manufacturing of final products, not just prototypes.

3. Healthcare

In healthcare, 3D printing creates prototypes for new product development in the medical and dental fields. In dentistry, 3D printing is also helpful in creating patterns for casting metal dental crowns and manufacturing tools for creating dental aligners.

The solution is also helpful for directly manufacturing knee and hip implants and other stock items and creating patient-specific items such as personalized prosthetics, hearing aids, and orthotic insoles. The possibility of 3D-printed surgical guides for particular operations and 3D-printed bone, skin, tissue, organs, and pharmaceuticals is being explored.

4. Aerospace

In aerospace, 3D printing is used for prototyping and product development. The solution is also critically helpful in aircraft development, as it helps researchers keep up with the strenuous requirements of R&D without compromising on the high industry standards. Certain non-critical or older aircraft components are 3D-printed for the flight!

5. Automotive

Automotive enterprises, especially those specializing in racing automobiles, such as those used in F1, leverage 3D printing for prototyping and manufacturing specific components. Organizations in this space are also exploring the possibility of using 3D printing to fulfill aftermarket demand by producing spare parts as customers require rather than stocking them up.

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Takeaway

The term ‘3D printing’ encompasses numerous technologies and processes that collectively offer a wide range of capabilities for producing components using various materials. The key similarity across 3D printing types is the additive layer-by-layer production process where no subtractive methodology, molding, or casting is required. Applications of 3D printing are rapidly emerging across industry verticals as the solution becomes more effective and affordable and penetrates deeply and widely across sectors.

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3D Printing: What It Is, How It Works and Examples

3D printers might seem like they're right out of a science fiction movie, but they're proving to be useful in a variety of industries. | Image: Shutterstock

How Do 3D Printers Work?

3D printing is part of the additive manufacturing family and uses similar methods to a traditional inkjet printer — albeit in 3D. Additive manufacturing describes the process of creating something in layers, adding material continuously until the final design is complete. This term most often refers to molding and 3D printing. 

It takes a combination of top-of-the-line software, powder-like materials and precision tools to create a three-dimensional object from scratch. Below are a few of the main steps 3D printers take to bring ideas to life.

How Does a 3D Printer Work?

3D printers are related to additive manufacturing. 3D printers use computer-aided design to understand a design. When a design is ready, a material that can be dispensed through a hot nozzle or precision tool is printed layer by layer to create a three-dimensional object from scratch.

 

3D Modeling Software

The first step of any 3D printing process is 3D modeling. To maximize precision — and because 3D printers can’t magically guess what you want to print — all objects have to be designed in a 3D modeling software. Some designs are too intricate and detailed for traditional manufacturing methods. That’s where CAD software comes in. 

Modeling allows printers to customize their product down to the tiniest detail. The 3D modeling software’s ability to allow for precision designs is why 3D printing is being hailed as a true game changer in many industries. This modeling software is especially important to an industry, like dentistry, where labs are using 3D software to design teeth aligners that precisely fit to the individual. It’s also vital to the space industry, where they use the software to design some of the most intricate parts of a rocketship.

 

3D PRINTERS USE MODELING AND SLICING SOFTWARE TO GUIDE THE PRINTER IN CREATING EACH OBJECT. Video: Digital Trends

 

Slicing the Model

Once a model is created, it’s time to “slice” it. Since 3D printers cannot conceptualize the concept of three dimensions, like humans, engineers need to slice the model into layers in order for the printer to create the final product. 

Slicing software takes scans of each layer of a model and will tell the printer how to move in order to recreate that layer. Slicers also tell 3D printers where to “fill” a model. This fill gives a 3D printed object internal lattices and columns that help shape and strengthen the object. Once the model is sliced, it’s sent off to the 3D printer for the actual printing process.

 

The 3D Printing Process

When the modeling and slicing of a 3D object is completed, it’s time for the 3D printer to finally take over. The printer acts generally the same as a traditional inkjet printer in the direct 3D printing process, where a nozzle moves back and forth while dispensing a wax or plastic-like polymer layer-by-layer, waiting for that layer to dry, then adding the next level. It essentially adds hundreds or thousands of 2D prints on top of one another to make a three-dimensional object.

3D Printing Materials

There are a variety of different materials that a printer uses in order to recreate an object to the best of its abilities. Here are some examples:

Acrylonitrile Butadiene Styrene (ABS)

Plastic material that is easy to shape and tough to break. The same material that LEGOs are made out of.

Carbon Fiber Filaments

Carbon fiber is used to create objects that need to be strong, but also extremely lightweight.

Conductive Filaments

These printable materials are still in the experimental stage and can be used for printing electric circuits without the need for wires. This is a useful material for wearable technology.

Flexible Filaments

Flexible filaments produce prints that are bendable, yet tough. These materials can be used to print anything from wristwatches to phone covers.

Metal Filament

Metal filaments are made of finely ground metals and polymer glue. They can come in steel, brass, bronze and copper in order to get the true look and feel of a metal object.

Wood Filament

These filaments contain finely ground wood powder mixed with polymer glue. These are obviously used to print wooden-looking objects and can look like a lighter or darker wood depending on the temperature of the printer.

The 3D printing process takes anywhere from a few hours for really simple prints, like a box or a ball, to days or weeks for much larger detailed projects, like a full-sized home.

How Much Do 3D Printers Cost?

The cost of 3D printers vary based on the size, specialty and use. The cheapest 3D printers, for entry level hobbyists, typically range from $100 to $500. More advanced models can range between $300 and $5,000. Industrial 3D printers can cost up to $100,000.

 

3D Printing Processes and Techniques

here are also different types of 3D printers depending on the size, detail and scope of a project. Each different type of printer will vary slightly on how an object gets printed.

Fused Deposition Modeling (FDM)

FDM is probably the most widely used form of 3D printing. It’s incredibly useful for manufacturing prototypes and models with plastic.

Stereolithography (SLA) Technology 

SLA is a fast prototyping printing type that is best suited for printing in intricate detail. The printer uses an ultraviolet laser to craft the objects within hours.

Digital Light Processing (DLP) 

DLP is one of the oldest forms of 3D printing. DLP uses lamps to produce prints at higher speeds than SLA printing because the layers dry in seconds.

Continuous Liquid Interface Production (CLIP) 

CLIP is amongst the faster processes that use Vat Photopolymerisation. The CLIP process utilizes Digital Light Synthesis technology to project a sequence of UV images across a cross-section of a 3D printed part, resulting in a precisely controlled curing process. The part is then baked in a thermal bath or oven, causing several chemical reactions that allow the part to harden.

Material Jetting 

Material Jetting applies droplets of material through a small diameter nozzle layer-by-layer to build a platform, which becomes hardened by UV light.

Binder Jetting 

Binder Jetting utilizes a powder base material layered evenly along with a liquid binder, which is applied through jet nozzles to act as an adhesive for the powder particles.

Fused Deposition Modeling (FDM)

FDM, also known as Fused Filament Fabrication (FFF), works by unwinding a plastic filament from a spool and flowing through a heated nozzle in horizontal and vertical directions, forming the object immediately as the melted material hardens.

Selective Laser Sintering (SLS) 

A form of Powder Bed Fusion, SLS fuses small particles of powder together by use of a high-power laser to create a three-dimensional shape. The laser scans each layer on a powder bed and selectively fuses them, then lowering the powder bed by one thickness and repeating the process through completion.

Multi-Jet Fusion (MJF) 

Another form of Powder Bed Fusion, MJF uses a sweeping arm to deposit powder and an inkjet-equipped arm to apply binder selectively on top. Next, a detailing agent is applied around the detailing agent for precision. Finally, thermal energy is applied to cause a chemical reaction. Direct Metal Laser Sintering (DMLS) also utilizes this same process but with metal powder specifically.

Sheet Lamination

Sheet Lamination binds material in sheets through external force and welds them together through layered ultrasonic welding. The sheets are then milled in a CNC machine to form the object’s shape.

Directed Energy Deposition

Directed Energy Deposition is common in the metal industry and operates by a 3D printing apparatus attached to a multi-axis robotic arm with a nozzle for applying metal powder. The powder is applied to a surface and energy source, which then melts the material to form a solid object.

What is 3D printing and how it can be used! Interesting!

What is 3D printing

3D printing technology was patented in the 80s of the last century, but gained popularity relatively recently. New, promising techniques have been developed and the possibilities of 3D technologies have reached a completely new level. However, to this day, the technique is not known in all circles, and not everyone is aware of what 3D printing is. In today's article, we will try to explain in detail and in an accessible way what 3D printing is and where it is used.

In short, 3D printing is a technique for manufacturing three-dimensional products based on digital models. Regardless of the specific technology, the essence of the process is the gradual layer-by-layer reproduction of objects.
This process uses a special device - a 3D printer, which prints certain types of materials. More details about it are written here. Other names for the technology are rapid prototyping or additive manufacturing. Often the phrase "additive technologies" is used in the meaning of "3D technologies".

3D printing steps

To make it clearer what 3D printing is, let's take a look at the playback process step by step. Below are the specific stages of 3D printing. How it works:

  • 3D modeling of the required object is performed according to certain rules;
  • The file with the digital model is loaded into the slicer program, which generates the control code for the 3D printer;
  • Sets required 3D printing options;
  • The code is written to a removable memory that connects to the 3D printer;
  • 3D model reproduced.

Objects are reproduced gradually. According to the required shape, the selected material is applied layer by layer, forming the finished product. It is worth noting that the possibilities of 3D printing are almost limitless, that is, anything can be made. In some technologies, very thin overhanging elements are provided with supports, thanks to which they can be avoided from sagging.
Naturally, this is a very simplified description of the stages of 3D printing, but they give a very clear idea of ​​the essence of the technique.

Other questions and answers about 3D printers and 3D printing:

  • Basics What is 3D scanning?
  • Basics What is a 3D model?

3D Printing Technologies

Different 3D printing technologies are used to reproduce different objects. They differ both in the consumables used, and in the speed and accuracy of printing. Here are the main 3D printing technologies:

  • Fused deposition modeling (FDM) . One of the most common 3D printing technologies, used in most desktop 3D printers, and represents an ideal price / quality ratio. Printing occurs by layer-by-layer supply of a thread of molten plastic;
  • Laser stereolithography (SLA) . The formation of the object occurs due to the layer-by-layer illumination of a liquid photopolymer resin by a laser, which hardens under the influence of radiation. One of the variations of this technology is DLP 3D printing. It uses a special projector instead of a laser. Both 3D printing methods are used to create objects with a high degree of detail. In the case of DLP printing, speed is also an added advantage;
  • Selective laser sintering (SLS) . Reproduction is performed by layer-by-layer melting of a special powder under the action of laser radiation. This 3D printing method is widely used in the industry for the manufacture of durable metal elements

3D Printing Applications

As you may have guessed by now, 3D printing is extremely versatile. The second name of the technology - rapid prototyping - speaks for itself. In the manufacture of prototypes and models of models, 3D printing can be simply indispensable. It is also a very cost-effective solution for small-scale production. In the aerospace and automotive industries, 3D technologies are already being used with might and main due to the high profitability and speed of manufacturing components. Culinary professionals are working on the development of 3D food printers, and in medicine, 3D printing has become something of a technology of the future. With the help of 3D bioprinting, it is planned to produce bones, organs and living tissues, but for now, implants and full-fledged medicines are printed on 3D printers. Desktop 3D printers can be used for domestic purposes: for repairs, making various household items, and so on. And designers, fashion designers, sculptors and artists appreciate the possibilities of 3D printing and 3D modeling as an unusual way to realize their talent.

Well, that was a brief description of what 3D printing is. We hope we were able to provide the necessary information in an accessible way. If you have additional questions that we have not covered, write to us by e-mail and we, if necessary, will add your questions! Best regards, 3DDevice team.

We also want to remind you about the possibility to order 3D printing, 3D scanning, 3D modeling services or purchase of related equipment and consumables with delivery throughout Ukraine in 3DDevice. If you have any questions, please contact us at one of the phone numbers listed here. We look forward to collaborating!

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3D printing for dummies or "what is a 3D printer?"

  • 1 3D printing term
  • 2 3D printing methods
    • 2.1 Extrusion printing
    • 2.2 Melting, sintering or gluing
    • 2.3 Stereolithography
    • 2.4 Lamination
  • 3 Fused Deposition Printing (FDM)
    • 3.1 Consumables
    • 3.2 Extruder
    • 3.3 Working platform
    • 3.4 Positioners
    • 3.5 Control
    • 3.6 Varieties of
      • FDM printers
  • 4 Laser stereolithography (SLA)
    • 4.1 Lasers and projectors
    • 4.2 Cuvette and resin
    • 4.3 Varieties of
      • Stereolithography Printers

The term 3D printing

The term 3D printing has several synonyms, one of which quite briefly and accurately characterizes the essence of the process - "additive manufacturing", that is, production by adding material. The term was not coined by chance, because this is the main difference between multiple 3D printing technologies and the usual methods of industrial production, which in turn received the name "subtractive technologies", that is, "subtractive". If during milling, grinding, cutting and other similar procedures, excess material is removed from the workpiece, then in the case of additive manufacturing, material is gradually added until a solid model is obtained.

Soon 3D printing will even be tested on the International Space Station

Strictly speaking, many traditional methods could be classified as "additive" in the broad sense of the word - for example, casting or riveting. However, it should be borne in mind that in these cases, either the consumption of materials is required for the manufacture of specific tools used in the production of specific parts (as in the case of casting), or the whole process is reduced to joining ready-made parts (welding, riveting, etc. ). In order for the technology to be classified as “3D printing”, the final product must be built from raw materials, not blanks, and the formation of objects must be arbitrary - that is, without the use of forms. The latter means that additive manufacturing requires a software component. Roughly speaking, additive manufacturing requires computer control so that the shape of final products can be determined by building digital models. It was this factor that delayed the widespread adoption of 3D printing until the moment when numerical control and 3D design became widely available and highly productive.

3D printing techniques

There are many 3D printing technologies, and even more names for them due to patent restrictions. However, you can try to divide technologies into main areas:

Extrusion printing

This includes techniques such as deposition fusion (FDM) and multi-jet printing (MJM). This method is based on the extrusion (extrusion) of consumables with the sequential formation of the finished product. As a rule, consumables consist of thermoplastics or composite materials based on them.

Melting, sintering or bonding

This approach is based on bonding powdered material together. Formation is done in different ways. The simplest is gluing, as is the case with 3D inkjet printing (3DP). Such printers deposit thin layers of powder onto the build platform, which are then selectively bonded with a binder. Powders can be made up of virtually any material that can be ground to a powder—plastic, wood, metal.

This model of James Bond's Aston Martin was successfully printed on a Voxeljet SLS printer and blown up just as successfully during the filming of Skyfall instead of the expensive original

sintering (SLS and DMLS) and smelting (SLM), which allow you to create all-metal parts. As with 3D inkjet printing, these devices apply thin layers of powder, but the material is not glued together, but sintered or melted using a laser. Laser sintering (SLS) is used to work with both plastic and metal powders, although metal pellets usually have a more fusible shell, and after printing they are additionally sintered in special ovens. DMLS is a variant of SLS installations with more powerful lasers that allow sintering metal powders directly without additives. SLM printers provide not just sintering of particles, but their complete melting, which allows you to create monolithic models that do not suffer from the relative fragility caused by the porosity of the structure. As a rule, printers for working with metal powders are equipped with vacuum working chambers, or they replace air with inert gases. Such a complication of the design is caused by the need to work with metals and alloys subject to oxidation - for example, with titanium.

Stereolithography

How an SLA printer works

Stereolithography printers use special liquid materials called "photopolymer resins". The term "photopolymerization" refers to the ability of a material to harden when exposed to light. As a rule, such materials react to ultraviolet irradiation.

Resin is poured into a special container with a movable platform, which is installed in a position near the surface of the liquid. The layer of resin covering the platform corresponds to one layer of the digital model. Then a thin layer of resin is processed by a laser beam, hardening at the points of contact. At the end of illumination, the platform together with the finished layer is immersed to the thickness of the next layer, and illumination is performed again.

Lamination

3D printers using lamination technology (LOM)

Some 3D printers build models using sheet materials - paper, foil, plastic film.

Layers of material are glued on top of each other and cut along the contours of the digital model using a laser or blade.

These machines are well suited for prototyping and can use very cheap consumables, including regular office paper. However, the complexity and noise of these printers, coupled with the limitations of the models they produce, limit their popularity.

Fused deposition modeling (FDM) and laser stereolithography (SLA) have become the most popular 3D printing methods used in the home and office.

Let's take a closer look at these technologies.

Fused Deposition Printing (FDM)

FDM is perhaps the simplest and most affordable 3D construction method, which is the reason for its high popularity.
High demand for FDM printers is driving device and consumable prices down rapidly, along with technology advances towards ease of use and improved reliability.

Consumables

ABS filament spool and finished model

FDM printers are designed to print with thermoplastics, which are usually supplied as thin filaments wound on spools. The range of "clean" plastics is very wide. One of the most popular materials is polylactide or "PLA plastic". This material is made from corn or sugar cane, which makes it non-toxic and environmentally friendly, but makes it relatively short-lived. ABS plastic, on the other hand, is very durable and wear-resistant, although it is susceptible to direct sunlight and can release small amounts of harmful fumes when heated. Many plastic items that we use on a daily basis are made from this material: housings for household appliances, plumbing fixtures, plastic cards, toys, etc.

In addition to PLA and ABS, printing is possible with nylon, polycarbonate, polyethylene and many other thermoplastics that are widely used in modern industry. More exotic materials are also possible, such as polyvinyl alcohol, known as "PVA plastic". This material dissolves in water, which makes it very useful for printing complex geometric patterns. But more on that below.

Model made from Laywoo-D3. Changing the extrusion temperature allows you to achieve different shades and simulate annual rings

It is not necessary to print with homogeneous plastics. It is also possible to use composite materials imitating wood, metals, stone. Such materials use all the same thermoplastics, but with impurities of non-plastic materials.

So, Laywoo-D3 consists partly of natural wood dust, which allows you to print "wooden" products, including furniture.

The material called BronzeFill is filled with real bronze, and models made from it can be ground and polished, achieving a high similarity to products made from pure bronze.

One has only to remember that thermoplastics serve as a connecting element in composite materials - they determine the thresholds of strength, thermal stability and other physical and chemical properties of finished models.

Extruder

Extruder - FDM print head. Strictly speaking, this is not entirely true, because the head consists of several parts, of which only the feed mechanism is directly "extruder". However, by tradition, the term "extruder" is commonly used as a synonym for the entire print assembly.

FDM extruder general design

The extruder is designed for melting and applying thermoplastic thread. The first component is the thread feed mechanism, which consists of rollers and gears driven by an electric motor. The mechanism feeds the thread into a special heated metal tube with a small diameter nozzle, called a "hot end" or simply a "nozzle". The same mechanism is used to remove the thread if a change of material is needed.

The hot end is used to heat and melt the thread fed by the puller. As a rule, nozzles are made from brass or aluminum, although more heat-resistant, but also more expensive materials can be used. For printing with the most popular plastics, a brass nozzle is quite enough. The “nozzle” itself is attached to the end of the tube with a threaded connection and can be replaced with a new one in case of wear or if a change in diameter is necessary. The nozzle diameter determines the thickness of the molten filament and, as a result, affects the print resolution. The heating of the hot end is controlled by a thermistor. Temperature control is very important, because when the material is overheated, pyrolysis can occur, that is, the decomposition of plastic, which contributes both to the loss of the properties of the material itself and to clogging of the nozzle.

PrintBox3D One FDM Extruder

To prevent the filament from melting too early, the top of the hot end is cooled by heatsinks and fans. This point is of great importance, since thermoplastics that pass the glass transition temperature significantly expand in volume and increase the friction of the material with the walls of the hot end. If the length of such a section is too long, the pulling mechanism may not have enough strength to push the thread.

The number of extruders may vary depending on the purpose of the 3D printer. The simplest options use a single print head. The dual extruder greatly expands the capabilities of the device, allowing you to print one model in two different colors, as well as using different materials. The last point is important when building complex models with overhanging structural elements: FDM printers cannot print “over the air”, since the applied layers require support. In the case of hinged elements, temporary support structures have to be printed, which are removed after printing is completed. The removal process is fraught with damage to the model itself and requires accuracy. In addition, if the model has a complex structure with internal cavities that are difficult to access, building conventional supports may not be practical due to the difficulty in removing excess material.

Finished model with PVA supports (white) before and after washing

In such cases, the very water-soluble polyvinyl alcohol (PVA) comes in handy. Using a dual extruder, you can build a model from waterproof thermoplastic using PVA to create supports.

After printing, PVA can be simply dissolved in water and a complex product of perfect quality can be obtained.

Some FDM printers can use three or even four extruders.

Work platform

Heated platform covered with removable glass work table

Models are built on a special platform, often equipped with heating elements. Preheating is required for a wide range of plastics, including the popular ABS, which are subject to a high degree of shrinkage when cooled. The rapid loss of volume by cold coats compared to freshly applied material can lead to model distortion or delamination. The heating of the platform makes it possible to significantly equalize the temperature gradient between the upper and lower layers.

Heating is not recommended for some materials. A typical example is PLA plastic, which requires a fairly long time to harden. Heating PLA can lead to deformation of the lower layers under the weight of the upper ones. When working with PLA, measures are usually taken not to heat up, but to cool the model. Such printers have characteristic open cases and additional fans blowing fresh layers of the model.

Calibration screw for work platform covered with blue masking tape

The platform needs to be calibrated before printing to ensure that the nozzle does not hit the applied layers and move too far causing air-to-air printing resulting in plastic vermicelli. The calibration process can be either manual or automatic. In manual mode, calibration is performed by positioning the nozzle at different points on the platform and adjusting the platform inclination using the support screws to achieve the optimal distance between the surface and the nozzle.

As a rule, platforms are equipped with an additional element - a removable table. This design simplifies the cleaning of the working surface and facilitates the removal of the finished model. Stages are made from various materials, including aluminum, acrylic, glass, etc. The choice of material for the manufacture of the stage depends on the presence of heating and consumables for which the printer is optimized.

For a better adhesion of the first layer of the model to the surface of the table, additional tools are often used, including polyimide film, glue and even hairspray! But the most popular tool is inexpensive, but effective masking tape. Some manufacturers make perforated tables that hold the model well but are difficult to clean. In general, the expediency of applying additional funds to the table depends on the consumable material and the material of the table itself.

Positioning mechanisms

Operation of positioning mechanisms

Of course, the print head must move relative to the working platform, and unlike conventional office printers, positioning must be done not in two, but in three planes, including height adjustment.

Positioning pattern may vary. The simplest and most common option involves mounting the print head on perpendicular guides driven by stepper motors and providing positioning along the X and Y axes.

Vertical positioning is carried out by moving the working platform.

On the other hand, it is possible to move the extruder in one plane and the platforms in two.

SeemeCNC ORION Delta Printer

One option that is gaining popularity is the delta coordinate system.

Such devices are called "delta robots" in the industry.

In delta printers, the print head is suspended on three manipulators, each of which moves along a vertical rail.

The synchronous symmetrical movement of the manipulators allows you to change the height of the extruder above the platform, and the asymmetric movement causes the head to move in the horizontal plane.

A variant of this system is the reverse delta design, where the extruder is fixed to the ceiling of the working chamber, and the platform moves on three support arms.

Delta printers have a cylindrical build area, and their design makes it easy to increase the height of the working area with minimal design changes by extending the rails.

In the end, everything depends on the decision of the designers, but the fundamental principle does not change.

Control

Typical Arduino-based controller with add-on modules

FDM printer operation, including nozzle and platform temperature, filament feed rate, and stepper motors for positioning the extruder, is controlled by fairly simple electronic controllers. Most controllers are based on the Arduino platform, which has an open architecture.

The programming language used by printers is called G-code (G-Code) and consists of a list of commands executed in turn by the 3D printer systems. G-code is compiled by programs called "slicers" - standard 3D printer software that combines some of the features of graphics editors with the ability to set print options through a graphical interface. The choice of slicer depends on the printer model. RepRap printers use open source slicers such as Skeinforge, Replicator G and Repetier-Host. Some companies make printers that require proprietary software.

Program code for printing is generated using slicers

As an example, we can mention Cube printers from 3D Systems. There are companies that offer proprietary software but allow third-party software, as is the case with the latest generation of MakerBot 3D printers.

Slicers are not intended for 3D design per se. This task is done with CAD editors and requires some 3D design skills. Although beginners should not despair: digital models of a wide variety of designs are offered on many sites, often even for free. Finally, some companies and individuals offer 3D design services for custom printing.

Finally, 3D printers can be used in conjunction with 3D scanners to automate the process of digitizing objects. Many of these devices are designed specifically to work with 3D printers. Notable examples include the 3D Systems Sense handheld scanner and the MakerBot Digitizer handheld desktop scanner.

MakerBot Replicator 5th Generation FDM Printer with built-in control module on the top of the frame

The user interface of a 3D printer can consist of a simple USB port for connecting to a personal computer. In such cases, the device is actually controlled by the slicer.

The disadvantage of this simplification is a rather high probability of printing failure when the computer freezes or slows down.

A more advanced option includes an internal memory or memory card interface to make the process standalone.

These models are equipped with control modules that allow you to adjust many print parameters (such as print speed or extrusion temperature). The module may include a small LCD display or even a mini-tablet.

Varieties of FDM printers

Stratasys Fortus 360mc professional FDM printer that allows printing with nylon

FDM printers are very, very diverse, ranging from the simplest home-made RepRap printers to industrial installations capable of printing large-sized objects.

Stratasys, founded by Scott Crump, the inventor of FDM technology, is a leader in the production of industrial installations.

You can build the simplest FDM printers yourself. Such devices are called RepRap, where "Rep" indicates the possibility of "replication", that is, self-reproduction.

RepRap printers can be used to print custom made plastic parts.

Controller, rails, belts, motors and other components can be easily purchased separately.

Of course, assembling such a device on your own requires serious technical and even engineering skills.

Some manufacturers make it easy by selling DIY kits, but these kits still require a good understanding of the technology.

A variant of the popular late 3rd generation Prusa RepRap printer

If you like to make things with your own hands, then RepRap printers will pleasantly please you with the price: the average cost of the popular early generation Prusa Mendel design is about $500 in a complete set.

And, despite their "do-it-yourself nature", RepRap printers are quite capable of producing models with quality at the level of expensive branded counterparts.

Ordinary users who do not want to delve into the intricacies of the process, but require only a convenient device for household use, can purchase a ready-made FDM printer.

Many companies are focusing on the development of the consumer market segment, offering 3D printers for sale that are ready to print "straight out of the box" and do not require serious computer skills.

3D Systems Cube consumer 3D printer

The most famous example of a consumer 3D printer is the 3D Systems Cube.

While it doesn't boast a huge build area, ultra-fast print speeds, or superb build quality, it's easy to use, affordable, and safe: This printer has received the necessary certification to be used even by children.

Mankati FDM printer demonstration: http://youtu. be/51rypJIK4y0

Laser Stereolithography (SLA)

Stereolithographic 3D printers are widely used in dental prosthetics

Stereolithographic printers are the second most popular and widespread after FDM printers.

These units deliver exceptional print quality.

The resolution of some SLA printers is measured in a matter of microns - it is not surprising that these devices quickly won the love of jewelers and dentists.

The software side of laser stereolithography is almost identical to FDM printing, so we will not repeat ourselves and will only touch on the distinctive features of the technology.

Lasers and projectors

Projector illumination of a photopolymer model using the Kudo3D Titan DLP printer as an example

The cost of stereolithography printers is rapidly declining, due to growing competition due to high demand and the use of new technologies that reduce the cost of construction.

Although the technology is generically referred to as "laser" stereolithography, most recent developments use UV LED projectors for the most part.

Projectors are cheaper and more reliable than lasers, do not require the use of delicate mirrors to deflect the laser beam, and have higher performance. The latter is explained by the fact that the contour of the whole layer is illuminated as a whole, and not sequentially, point by point, as is the case with laser options. This variant of the technology is called projection stereolithography, "DLP-SLA" or simply "DLP". However, both options are currently common - both laser and projector versions.

Cuvette and resin

Photopolymer resin is poured into a cuvette

A photopolymer resin that looks like epoxy is used as consumables for stereolithographic printers. Resins can have a variety of characteristics, but they all share one key feature for 3D printing applications: these materials harden when exposed to ultraviolet light. Hence, in fact, the name "photopolymer".

When polymerized, resins can have a wide variety of physical characteristics. Some resins are like rubber, others are hard plastics like ABS. You can choose different colors and degrees of transparency. The main disadvantage of resins and SLA printing in general is the cost of consumables, which significantly exceeds the cost of thermoplastics.

On the other hand, stereolithography printers are mainly used by jewelers and dentists who do not need to build large parts but appreciate the savings from fast and accurate prototyping. Thus, SLA printers and consumables pay for themselves very quickly.

An example of a model printed on a 3D laser stereolithography printer

Resin is poured into a cuvette, which can be equipped with a lowering platform. In this case, the printer uses a leveling device to flatten the thin layer of resin covering the platform just prior to irradiation. As the model is being made, the platform, together with the finished layers, is “embedded” in the resin. Upon completion of printing, the model is removed from the cuvette, treated with a special solution to remove liquid resin residues and placed in an ultraviolet oven, where the final illumination of the model is performed.

Some SLA and DLP printers work in an "inverted" scheme: the model is not immersed in the consumable, but "pulled" out of it, while the laser or projector is placed under the cuvette, and not above it. This approach eliminates the need to level the surface after each exposure, but requires the use of a cuvette made of a material transparent to ultraviolet light, such as quartz glass.

The accuracy of stereolithographic printers is extremely high. For comparison, the standard for vertical resolution for FDM printers is considered to be 100 microns, and some variants of SLA printers allow you to apply layers as thin as 15 microns. But this is not the limit. The problem, rather, is not so much in the accuracy of lasers, but in the speed of the process: the higher the resolution, the lower the print speed. The use of digital projectors allows you to significantly speed up the process, because each layer is illuminated entirely. As a result, some DLP printer manufacturers claim to be able to print with a vertical resolution of one micron!

Video from CES 2013 showing Formlabs Form1 stereolithography 3D printer in action: http://youtu.be/IjaUasw64VE

Stereolithography Printer Options

Formlabs Form1 Desktop Stereolithography Printer

As with FDM printers, SLA printers come in a wide range in terms of size, features and cost. Professional installations can cost tens if not hundreds of thousands of dollars and weigh a couple of tons, but the rapid development of desktop SLA and DLP printers is gradually reducing the cost of equipment without compromising print quality.

Models such as the Titan 1 promise to make stereolithographic 3D printing affordable for small businesses and even home use at prices in the region of $1,000.

Learn more