Companies that 3D printers are getting cheaper and more popular, with their different types of 3D printing, and they are being used for more and more applications. They not only serve to print three-dimensional objects for makers, engineers, architects, etc., now they can also print living fabrics for medical applications, printed homes, industrial production, in motorsport to create parts, for printed food, etc.
If you are considering buy a 3D printer for home or for your business, you should know the types of 3D printing, the differences, etc. In addition, you will also know some keys to be able to better choose your new printing equipment ...
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How to choose a 3D printer and types of 3D printing?
Not only do the types of 3D printing matter when choosing a 3D printer, many other parameters also play a role. To make a good choice, you should focus on three essential questions:
- How much can I spend? You will find very cheap printers, from a few hundred euros, to others that cost thousands of euros. Everything will depend on whether you want them for home use or for more professional uses.
- For what? Another important question. Not only for the price, but also for the performance of the 3D printer. For example, to make small pieces of home, you do not care too much that it is small and with a lower speed. But to make larger models, you will have to look for printers that go beyond 6 or 8 ″.
- What materials do I need? For domestic parts, with the usual plastic polymers such as PLA, ABS, PETG, etc., it will be enough. Instead, some professional / industrial applications may involve the use of fabrics, metals, nylon, etc.
Types of materials:
Depending on the requirements of the parts, you will need one or another type of impression material. Obviously, home printers, which I will focus on, do not accept all types of materials. It is one of the specifications shown, and the filaments that usually support are:Filament rolls are usually cheap, and are sold in different lengths and thicknesses. For example, they can range from 1.75mm to 3mm. The thickness must match the one supported by the extrusion head of your 3D printer.
- ABS: Acrylonitrile butadiene styrene is a fairly common thermoplastic (eg: LEGO pieces are made from this material). It is not biodegradable, but it is hard and has a certain stiffness to build solid structures. It also has great chemical resistance, it only dissolves with acetone. It resists well to abrasion, and to temperature, but it can be damaged if left outdoors due to UV exposure.
- PLA- Polylactic acid is biodegradable (made from seeds, such as cornstarch), so it is more environmentally friendly and can be used for gardening projects. It is valid for use as kitchen utensils, such as glasses, plastics, cutlery, etc. Although the finish is not as smooth as ABS, it has a superior gloss.
- HIPSHigh-impact polystyrene is very similar to ABS, although it is not as common as the previous ones.
- PET: Polyethylene terephthalate is common in bottles of mineral water or soft drinks, also in other food packaging. It is transparent and resistant to impacts very well.
- Laywoo-d3: It can change color (light / dark) with temperature, which gives it a multitude of utilities for use in some applications that involve temperature control. Its properties are similar to PLA, it is solid, and its texture is similar to wood, with veins.
- Ninjaflex: thermoplastic elastomer (TPE) is a very revolutionary new material, with great flexibility. If you are looking to make pieces that flex, this is what you are looking for.
- Nylon: It is a very popular (non-polymer) material, a type of fiber for fabrics that is used in clothes, cords, and many other objects. It is not easy to control, so the details of the pieces will not be very good, it also picks up moisture. In its favor it has the great resistance to temperature and stress.
Types of 3D printing
In addition to the material, they also matter the types of 3D printing. Just like when you choose a paper printer, you think if you want an inkjet printer, or a laser, LED, etc., when you choose a 3D printer you should also pay attention to the technology it uses, since it will depend on it. performance and results:
- FDM (Fused Deposition Modeling) or FFF (Fused Filament Fabrication): It is a type of molten deposition modeling of the polymer. The filament is heated and melted for extrusion. The head will move with the X, Y coordinates according to the information in the print file to recreate the object. The platform on which it is built is also mobile in this case, and it will move in the Z direction to create layer by layer. The advantages of this technique is that it is efficient and fast, although it is not suitable for models with parts that protrude too much, since it is done from the bottom up.
- SLA (StereoLithography): stereolithography is a fairly old system in which a photosensitive liquid resin is used that will be hardened by a laser. This is how layers are created until the final piece is achieved. It has the same limitations as FDM, but it achieves objects with very fine surfaces and with many details.
- DLP (Digital Light Processing)- Digital light processing is one of a kind of 3D printing similar to SLA, but it uses light-hardened liquid photopolymers. The result is objects with very good resolutions and very robust.
- SLS (Selective Laser Sintering): Selective laser sintering is similar to DLP and SLA, but instead of liquids they use powder. It is used for printers with nylon, aluminum, and other materials of this type. The laser will adhere the dust particles to form the objects. You can create difficult-to-create parts using molds or extrusion.
- SLM (Selective Laser Melting): It is quite advanced and expensive technology, similar to the SLS. Selective laser melting is used, and is used primarily in industry to melt metal powders and create parts.
- EBM (Electron Beam Melting): This technology is also very advanced and expensive, geared towards the industrial sector. It uses a fusion of the material using an electron beam. It can even melt metal powders and reaches a temperature of up to 1000ºC. Very complete and advanced forms can be generated.
- LOM (Laminated Object Manufacturing): is one of the types of 3D printing that uses laminate manufacturing. Sheets of paper, fabric, metal or plastic are used to form structures. These layers are joined by an adhesive and cut by laser. It is for industrial use.
- BJ (Binder jetting): binder injection is also used industrially. Use powder, like some other techniques. The dust is usually plaster, cement or other agglutinating that will join layers. Metal, sand or plastic can also be used.
- MJ (Material Jetting): material injection is another of the 3D printing technologies used in the jewelry industry. It has been used for years, and achieves great quality. Multiple layers are built on top of each other to create a solid piece. The head injects hundreds of tiny droplets of photopolymer and then cures (solidifies) them with ultraviolet (UV) light.
- MSLA (Masked SLA): It is a type of masked SLA, that is, it uses an LED matrix as a light source, emitting ultraviolet light through an LCD screen that shows a single layer sheet as a mask, hence the name. You can achieve very high print times, as each layer is fully exposed at once by the LCD, rather than tracing areas with the laser tip.
- DMLS (Direct Metal Laser Sintering)- It generates objects in a similar way to SLS, but the difference is that the powder does not melt, but is heated with the laser to the point where it can fuse at the molecular level. Due to the stresses, the pieces are usually somewhat fragile, although they can be subjected to a subsequent thermal process to make them more resistant.
- DOD (Drop On Demand)Drop-on-demand printing is another type of 3D printing. It uses two ink jets, one deposits the construction material and the other the dissolvable material for the supports. It also creates layer by layer like other techniques, but they also use a fly-cutter that polishes the build area to create each layer. Thus a perfectly flat surface is achieved. They are quite used in the industry for greater precision or to make molds.
Not all of these are for home use, some are intended for business or industrial use. In addition, there are other new methods that are emerging, although they are not as popular.
3D printers, regardless of the types of 3D printing, also have a number of technical characteristics that will determine performance. The most important that you should know are:
- Print speed: represents the speed with which the printer will finish printing the part. It is measured in millimeters per second. And they can be 40mm / s, 150mm / s, etc. The higher it is, the less time it will take to finish. Bear in mind that some pieces, if they are large and complex, could last hours ...
- Injector: it is the key piece, since it will be in charge of depositing the material to form the material, although not all types of 3D printing need one, since some work with liquid and light. But most of the domestic ones have it, and they are made up of the following parts:
- Hot tip: is the most important part. It is responsible for melting the filament by temperature. The temperature reached will depend on the types of materials accepted. It is important to choose systems with an active cooler.
- Nozzle: is the head opening, that is, where the fused filament comes out. There are large ones with better adhesions and speeds, but with lower resolution (less details). The small ones are slower, but much more precise to create very complex shapes with great detail.
- Extruder: the device on the other side of the hot tip. And it is the one that is in charge of extruding the molten material. You can find several types:
- Direct: they have better control and ease of work. They are so named because they are fed directly by the hot tip.
- Bowden: In this case, the molten filament will travel a certain distance between the hot tip and the extruder. This lightens the injector mechanism, reducing vibrations and allowing it to move faster.
- Warm bed: It is not present in all printers, but it is the support or base on which the part is printed. This part can be heated to ensure that the piece does not lose its temperature during the printing process, achieving better results. This is necessary for materials such as nylon, HIPS, or ABS. Otherwise, each layer would not stick well to the next. Printers for PET, PLA, PTU, etc., do not need a hot bed, and use a cold base.
- Ventilador- Because of high temperatures, printers often have fans to keep the system cool. This is important to maintain the reliability of the printer.
- STL: as you could see on the subject of printing software, most printers have accepted the standard STL format. Make sure your printer accepts these file formats.
- SupportAlthough the most popular printers are compatible with Windows, macOS and GNU / Linux, you should pay special attention to whether there are drivers for your system.
- EXTRASSome printers also include some other features that may be interesting, such as LCD screens with information about the process, WiFi connectivity to connect them in a network, built-in cameras to be able to film the printing process, etc.
- Assembled vs disassembled: Many printers come ready to unpack and use (for the more inexperienced), but if you like DIY, you can find some cheaper designs that you can assemble piece by piece using kits.