What materials were used to make the first 3d printer
What Materials Were Originally Used to Make a 3D Printer?
by Printed Ink
The ability to print three-dimensional objects has been represented in sci-fi movies before it was even possible. Some films like Dark Man and Westworld even predicted the ability to print out human parts.
All these predictions are coming to reality with the revolutionary invention of 3D printers. NٍِِASA is using 3D printing as a tool to invade Mars, while medical research institutions are experimenting with printing functioning body parts.
With the wide popularity of 3D printing, many are asking what materials were originally used to make 3D printer? In this post, we’ll answer this question by discussing the beginnings of the 3D printing era.
Contents
- 1 What Is 3D Printing?
- 2 When Was 3D Printing First Invented?
- 3 What Materials Were Originally Used for 3D Printing?
- 4 What Materials Are Used for 3D Printing?
- 4. 1 Polylactic Acid (PLA)
- 4.2 Acrylonitrile Butadiene Styrene (ABS)
- 4.3 Polyethylene Terephthalate Glycol (PETG)
- 4.4 Other Materials
- 4.5 More Examples for 3D printing materials:
- 5 Final Thoughts
What Is 3D Printing?
3D printing is the process of creating a three-dimensional object from a digital file. The process is also known by the name “additive manufacturing” as it’s done by building layers of the used material to create solid objects.
You can create anything you want with 3D printing. You can print out sunglasses, toys, aluminum parts, dental models, and even human tissues. This means that 3D printing isn’t going to be just a trend and it could be an invention that changes our world.
When Was 3D Printing First Invented?
Hideo Kodama was the first person to introduce 3D printing to the world in the early 1980s. He wanted to create a rapid prototyping technology (RP) to use as an affordable way to create product prototypes.
Unfortunately, Dr. Kodama missed the deadline and so failed to file his patent requirements. Four years later, three French engineers, Olivier de Witte, Jean-Claude André, and Alain le Méhauté, decided to create a rapid prototyping machine.
Similar to Kodama, the patent didn’t end up by their names. This time their application was abandoned because they couldn’t get the funding for it.
Three weeks later, the American Chuck Hull successfully filed his patent and became the first person to create a 3D printer.
What Materials Were Originally Used for 3D Printing?
Kodama used an acrylic-based substance called photopolymer. This is a photosensitive resin that turns into solid plastic once hit by an ultraviolet (UV) light beam creating a 3D object.
Chuck Hull then came with his stereolithography (SLA) invention and changed the whole game. His idea is somewhat similar to Kodama’s but his invention allows manufacturers to create 3D objects from digital data files using (CAD) computer-aided devices.
The process of 3D printing with SLA is pretty much similar to regular inkjet printing. To print a 3D object you need to upload specific digital files called CAD files to the printer and give the order to print. Here, the printer uses filaments of photopolymer resin instead of ink.
Then, the printing process lays down several layers of the filaments until it reaches the desired height and creates a 3D printed object.
There are several types of 3D printing besides SLA including Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), and more.
What Materials Are Used for 3D Printing?
It’s insane the number of materials that you can use in 3D printing. The most common materials used for 3D printing include:
Polylactic Acid (PLA)PLA is among the most used materials for 3D printing. It’s a thermoplastic polyester made from biodegradable products such as corn starch and sugarcane.
Polylactic acid is easy to print with and has a nice smell when heated, unlike other materials. It can be used for products that require detailed designs. However, it’s not used in products that require extreme stress tolerance.
Acrylonitrile Butadiene Styrene (ABS)ABS is another thermoplastic material. It’s recyclable, durable, and affordable. It’s the material that legos are made of.
Even though it’s harder to print than PLA, it’s being used pretty much in manufacturing everything from toys to kitchen appliances and computer keyboards.
Polyethylene Terephthalate Glycol (PETG)This is another thermoplastic material of the polyester family. It’s the same as PET but with the added glycol to improve its strength and durability. PETG’s biggest advantage is that it’s a food-safe material.
Like other materials, PETG has disadvantages too. It tends to scratch easier than other materials and can change color while printing as well.
Other MaterialsThermoplastics aren’t the only materials that can be used for 3D printing. Soon enough thousands and maybe more materials will be incorporated into the 3D printing industry.
More Examples for 3D printing materials:- Metals such as silver, gold, stainless steel, titanium, and more.
- Ceramics
- Food materials like chocolate
- Nylon
- Carbon fiber
- wood
Final Thoughts
3D printing is for sure going to change our future. Luckily, the prices of 3D printers have declined over the years and there are more customer-friendly options.
Also, more materials are being introduced to 3D printing. So basically, buying a 3D printer might be the best investment to make for the future whether it’s for manufacturing business or personal use.
What Materials Were Originally Used to Make 3D Printers?
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Smartphones, internet, fidget spinner, or 3D printers, every trend became popular at a particular time. 3D printer inventions date way back; however, it has become popular recently. The first 3D printer was developed in 1984 by Chuck Hull.
Table of Contents:
- The material used in 3D printing
- 1. Acrylic
- 2. Biodegradable
- 3. Graphite and Graphene
- 4. Paper
- 5. Nitinol
- 6. Plastic
- 7. Carbon fiber
- The different 3D printing technology used often in the past
- 1. Stereolithography
- 2. Digital light processing
- 3. Fused deposition modeling
- 4. Selective Laser Sintering
- Conclusion
3D printers build items from scratch with the use of a 3D scanner file or CAD using different types of materials. The material in which a 3D printer uses vary from plastic to metal to human body cell as well as foodstuffs such as chocolate. However, this highly depends on the printing technique. In this article, we shall be covering what materials were initially used to make 3D printers.
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The material used in 3D printing
1. Acrylic
Stereolithography was the first 3D printing process. It operated using Acrylic-based material referred to as a photopolymer. Chuck Hull copyrighted the term Stereolithography after three French investors abandoned the process.
In 1984, Chuck used a beam of ultraviolet light in stretching out the shape of an object in a vat of photopolymer liquid. The light hardened every layer on the surface, and the platform would go down for the next layer to harden
2. Biodegradable
Also known as bioFila is a unique 3D printer filament. In 1999, scientists used biodegradable materials in constructing the first 3D printed organ, which is implantable in human beings. Furthermore, Wake Forest Institute scientists were able to print a synthetic scaffold of the human bladder, which was then coated with a human patient cell.
Biodegradable 3D materials are perfect for the production of items that are of high quality.
3. Graphite and Graphene
Due to its conductivity and strength, graphite became the best choice in 3D printing. The material is perfect for developing highly flexible parts. Graphene was often used in developing building parts and solar panels. A Graphene proponent is the most flexible in most of 3D applicable materials.
Despite being used in 3D printing for long, graphene gained popularity after a partnership between an Australian company Kibaran Resources and 3D Group. Graphene was first used in 3D printing in 2004, and it one of the most electrically conductive materials in 3D printing. The material is light in weight and very strong at the same time. These features make it perfect for creating an array of products.
4. Paper
Paper has been used in 3D printing for long. Designs were printed on paper using 3D technology in order to achieve a realistic prototype, unlike on a fat illustration. When it comes to designing a proposal, a 3D model offers an excellent presentation for the convoying essence of the model with accuracy and in detail. This makes the paper a perfect material for the presentation since it gives a more vivid sense of whether the product should be abandoned or taken into fruition.
5. Nitinol
Nitinol was used in 3D printing for medical implants, and it has become one of the common materials used in the medical field. In 3D printing, Nitinol is valued due to its super-elasticity ability. The material is a mixture of nickel and titanium.
Nitinol is capable of bending into an extensive degree without breaking. You can restore Nitinol into its original form even when you fold it into half. Due to that, Nitinol is among the strongest and flexible 3D printing material. This product is perfect for the production of medical products. So far, Nitinol has accomplished aspects that were impossible to achieve.
6. Plastic
This is one of the oldest and most commonly used 3D printer filaments. Plastic is perfect for creating an array of products, from toys to household equipment. Due to their lightweight and easy to mold nature, plastic has become one of the common 3D printer filaments in the market. Furthermore, plastic is affordable and features an array of colors, which makes it perfect for creating toys.
Nowadays, plastic use in 3D printing has developed to become biodegradable, making it safe for the environment.
7. Carbon fiber
When 3D printing rose to fame, carbon fiber was among the first commonly used material. Carbon fiber filaments are perfect for coating plastic materials and increase their strength. Plastic and carbon fiber combination has grown in popularity among 3D printing industries due to their incredible strength. Due to that, carbon fiber can be used as an alternative to metal.
The different 3D printing technology used often in the past
1. Stereolithography
This was the first 3D printing process in history, and it is also known as SLA. Despite being the oldest, the process is still running to date. Just like before, most of the printing techniques use CAD files in processing objects, which is printed based on the printing machine understanding.
2. Digital light processing
Also known as DLP, it was first invented in 1987 by Larry Hornbeck from Texas. This 3D printing technology is similar to Stereolithography. Furthermore, it is popular in projectors, cell phones, and 3D printing productions.
DLP operates using digital micromirrors that are on a semiconductor chip. Despite that SLA and DLP runs on photopolymers, they have different light sources. DLP operates more on conventional sources, such as arc lamps.
3. Fused deposition modeling
Fused deposition modeling or FDM is the standard 3D printing technology. With this technology, you will be able to print concept models as well as final end-use models using an engineering-grade thermoplastic.
You should note that FDM is the only 3D printing technology that creates models using production-grade thermoplastic. This process produces excellent mechanical, chemical, and thermal quality products making appealing and useful to engineers as well as manufacturers.
4. Selective Laser Sintering
Selective Laser Sintering or SLS is a 3D technology that uses a laser as the primary power source in creating 3D models. SLS was invented by Carl Deckard, a Texas University student, and Joe Beaman, who was his professor in the year 1980.
SLS operates similarly to SLA; however, they differ in terms of material used. The powder is the primary material in SLS, while the liquid resin is the standard material is SLA. Furthermore, SLS does not feature a support structure since the 3D item printed is surrounded by powder.
Related: Best 3D Printers for Miniatures
Conclusion
3D printing technology has developed rapidly. You should note that the different models of 3D printers highly depend on the technology used. Nowadays, the 3D printer is more advanced and clever when compared to the previous models.
History of 3D printing
In this section, we wanted to trace the history of 3D printing from its inception to the present day, as well as give a forecast regarding the future development of technology.
The first 3d printer was invented by the American Charles Hull, he worked on the technology of stereolithography (SLA), a patent for the technology was issued in 1986. The printer was a fairly large industrial installation. The installation "grew" a three-dimensional model by applying a photopolymerizable material to a moving platform. The basis was a digital model pre-modeled on a computer (3D model). This 3d printer created three-dimensional objects, rising by 0.1-0.2 mm - the height of the layer. Despite the fact that the first device had many disadvantages, the technology has received its application. Charles Hull is also the co-founder of 3dsystems, one of the world's leading manufacturers of industrial 3D printers.
Charles Hull was not the only one to experiment with 3D printing technology, as in 1986 Carl Deckard invented Selective Laser Sintering (SLS). You can learn more about the method in another article, briefly: a laser beam sinters a powder (plastic, metal, etc.), while the mass of the powder is heated in the working chamber to a temperature close to the melting point. The basis is also a digital model pre-modeled on a computer (3D model). After the laser passes through the horizontal layer, the chamber is lowered to the layer height (usually 0.1-0.2 mm), the powder mass is leveled with a special device and a new layer is applied.
However, the most famous and widespread 3D printing method today is layer-by-layer direction (FDM). The idea of technology belongs to Scott Crump (Scott Crump), the patent dates back to 1988. You can learn more about the method in another article, in short: material (usually plastic) is fed from the heated nozzle of the print head using a stepper motor, the print head moves on linear guides along 1 or two axes, and the platform moves along 1 or 2 axes . The basis of the movement is also a 3D model. The molten plastic is laid on the platform along the established contour, after which the head or platform is moved and a new layer is applied on top of the old one. Scott Crump is one of the founders of Stratasys, which is also one of the leaders in the production of industrial 3D printers.
All the devices described above belonged to the class of industrial devices and were quite expensive, so one of the first 3d Dimension printers from Stratasys in 1991 cost from 50 to 220 thousand US dollars (depending on the model and configuration). Printers based on the technologies described above cost even more and until very recently, only a narrow circle of interested specialists knew about these devices.
Everything began to change since 2006, when the RepRap project (from the English Replicating Rapid Prototyper - a self-replicating mechanism for rapid prototyping) was founded, with the goal of creating a self-copying device, which was a 3D printer working on technology FDM (layer by layer deposition). Only, unlike expensive industrial devices, it looked like a clumsy invention made from improvised means. Metal shafts serve as a frame, they also serve as guides for the print head. driven by simple stepper motors. The software is open source. Almost all connecting parts are printed from plastic on the 3D printer itself. This idea originated among English scientists and aimed at spreading available additive technologies so that users can download 3D models on the Internet and create the necessary products, thus minimizing the production chain.
Leaving aside the ideological component, the community (which exists and develops to this day) managed to create a 3d printer accessible to the "ordinary person". So a set of unprinted parts can cost around a couple of hundred US dollars and a finished device from $500. And even though these devices looked unsightly and were significantly inferior in quality to their industrial counterparts, all this was an incredible impetus for the development of 3D printing technology.
As the RepRap project developed, 3D printers began to appear, taking as a basis the base laid down by the movement in technical and, sometimes, ideological terms (for example, commitment to the concept of open source - OpenSource). The companies that made printers tried to make them better both in terms of performance, design and user experience. The first RepRap printers cannot be called a commercial product, since it is not so easy to manage (and even more so to assemble) and it is not always possible to achieve stable work results. Nevertheless, companies tried to close the more than significant gap in quality, leaving a significant gap in cost whenever possible.
First of all, it is worth mentioning the MakerBot company, which started as a startup, took RepRap ideas as a basis and gradually turned them into a product of a new quality.
Their flagship product (and in our opinion the best to this day) remains the MakerBot Replicator 2 3D printer. The model was released in 2012 and later discontinued, but remains one of the most popular 3D printer models to this day " personal" segment (according to 3dhubs). The word "personal" is in brackets because this printer, which cost $2,200 at the time of release, was (and is) primarily used for business purposes, but falls into the personal segment due to its cost. This model differs from its progenitors (RepRap), being, in fact, a finished commercial product. Manufacturers abandoned the concept of OpenSource, closing all sources and software codes.
In parallel with the release of equipment, the company actively developed the Thingiverse resource, which contains many models for 3d printing, available for download for free. During the development of the first printer and beyond, the community has helped the company a lot, testing the product and offering various upgrades. After the release of the Replicator 2 (and the closure of development), the situation has changed. You can learn more about the history of MakerBot and other companies and people associated with 3d printing by watching the film Print the legend.
This film also highlights the history of Formlabs, one of the first companies to launch an affordable 3D printer based on SLA (Strereolithography) technology. The company raised funds for the first FORM 1 model through crowdfunding, encountered production difficulties, but eventually released an affordable and productive 3D printer, closing the quality gap described above.
And although the 3D printers described above were far from perfect, they laid the foundation for the development of affordable 3D printing technology, which continues to this day. At the moment, the quality of FDM and SLA printers is increasing, but there is no significant price reduction, rather, on the contrary, it is growing slightly. Along with FDM and SLA, many companies are developing in the field of powder sintering (SLS), as well as metal printing. Despite the fact that such printers cannot be called affordable, their price is much lower in comparison with analogues from the professional segment. It is also worth noting the development of the line of materials, in addition to the standard ABS and PLA plastics, today many different materials are used, including nylon, carbon fiber and other durable and refractory materials.
Personal 3d printers of today are very close to professional devices, the development of which also does not stop. In addition to the "founders" of the technology (Stratasys, 3dsystems), many small companies specializing in industrial 3D printing technologies (metal in particular) have emerged. 3D printing is also attracting the attention of large corporations, which, with varying degrees of success, are striving to take their place in a growing market. Here it is worth highlighting HP, which recently released the HP Jet Fusion 3D 4200 model, which has gained popularity among 3d printing professionals (as of 2018, it is at the top of the ranking of professional 3D printers in the quarterly reports of the 3dhubs portal).
However, 3D printing technologies are developing not only in breadth, but also in depth. One of the main disadvantages of 3D printing, compared to other production methods, is the low speed of creating models. A significant advance in terms of accelerating 3D printing was the invention of CLIP technology by CARBON, printers operating on this technology can produce models 100 times faster than classic SLA technology.
There is also a constant expansion of the range, properties and quality of materials and post-processing of products. All this accelerates the transition to the use of 3d printers in production, and not just as prototyping devices. Today, many large and not only companies and organizations are closely using a 3D printer in their production chain: from consumer goods manufacturers NIKE and PUMA to BOEING and SPACE X (the latter prints engine parts for its rockets that could not be made in any other way) .
In addition to the "classic" scope of 3D printing, today more and more often you can see news about how a house or some organ (or rather, a small part of it) was printed on a 3D printer from bio-material. And this is true, several companies around the world are testing or already partially using 3D printing in the construction of buildings and structures. This mainly concerns the contour pouring of walls (similar to the FDM method) with a special composite concrete mixture. And in Amsterdam there is a 3D printed bridge project and this list will only expand over time, since the use of 3D printing in construction can significantly reduce costs and increase the speed of work at certain stages.
With regards to medicine, here 3D printing also finds application, but at the moment it is not printing organs, but rather the use of technology in prosthetics (of various kinds) and bone replacement. Also, 3D printing technology is widely used in dentistry (SLA technology). Regarding the printing of organs, this is still far in the future, at the moment bio-3D printers are experimental facilities in the early stages, the success of which is limited to printing a few limited-viable cells.
Looking to the future, it is safe to say that 3D printing technology will expand both in breadth and depth, improving technology, speeding up processes, improving quality and improving material properties. 3D printers will increasingly replace old methods in production chains of various scales, and world production, due to this, will move towards the “on demand” scheme of work, increasing the degree of product customization. Perhaps someday, 3D printers will be widely used at the household level for the production of necessary things (the dream and goal of the RepRap movement), but this requires not only the development of technology, but also a paradigm shift in social thinking, as well as the development of a powerful design ecosystem ( 3d modeling) products (which is often forgotten).
3d printing of houses (and other structures) will no doubt also develop, reducing costs and production time, which, together with the development of new approaches in architecture and urban planning (such as modular construction and the prefabricated method), will give a tangible impetus to development the industry as a whole.
Biological 3D printers will be an important tool in scientific research. However, before they appear in hospitals and clinics, where they will print new organs, it is still very, very far away (in fact, this is science fiction).
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
3D printing term
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 methods such as Fused Deposition (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
Laminating (LOM) 3D printers workflow
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 a 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 binding 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 Printer 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 simply be 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
Scheme of positioning mechanisms
Of course, the print head must move relative to the working platform, and unlike conventional office printers, positioning must be carried out 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 lengthening 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 relatively 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.
Printing code generated by slicers
An example is the Cube line of 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 designed 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 homemade RepRap printers to industrial installations capable of printing large-sized objects.
Stratasys, founded by FDM inventor Scott Crump, is a leader in industrial plant manufacturing.
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 built 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. RepRap Printers
And, despite their "homemade 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 speed, or superb model 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 Kudo3D Titan DLP printer as an example
The cost of stereolithographic 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 collectively 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 stereolithography 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, stereolithographic 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 laser stereolithographic 3D printer. 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 around $1,000. Formlabs' Form 1 is available now for a factory selling price of $3,299.
The developer of the same DLP printer Peachy generally intends to overcome the lower price barrier of $100.
At the same time, the cost of photopolymer resins remains quite high, although the average price has fallen from $150 to $50 per liter over the past couple of years.