The Data Base
Types of 3D Printing Tech
Iliya Papoulias
Embedded Files
There are many types of 3D printing technology that are commonly used on the market today. As an average 3d printing user I found getting into 3D printing was a daunting task. I found you needed to do a lot of research to figure out which printer suited me and if it was worth the money. The 3 main 3D printing technologies are FDM (Fused deposition modeling), resin based 3D printers, and SLS (Selective Laser Sintering). There are other 3D printing technologies that are used but are less common which are Digital Light Processing (DLP), Selective Laser Melting (SLM), Electron Beam Melting (EMB), Laminated Object Manufacturing (LOM), Binder Jetting (BJ), and Material Jetting/Wax Casting. In this article I will be explaining in depth about the 3 major 3D printing technologies to help give insight on which one is right for you.
The gateway to 3D printing: Fused Deposition Modeling
How does it work?
FDM (Fused deposition modeling) works similar to a hot glue gun. FDM printers use a system of gears to push the filament (or the material) through a nozzle (extruder) or some type of heating device to melt filament that is extruded or pushed through the printed head. The printer then stacks the melted filament by “drawing” the shape of the object layer by layer. The print head is able to move on some printers in the X and Y directions onto a base or build plate that moves in the Z direction with some 3D printers build plates only being able to move in the Z direction or having no movement. Most 3d printers have a heated bed on the build plate as it helps the layers adhere better and helps increase the quality of the print compared to printers without them. Without a heated bed the 3d print can experience warping which is when the filament when the melting point of the material cools down while at room temperature. As the 3d printer prints the object layer by layer the extruder heats up and the filament cools down at room temperature the material will shrink causing it to adhere from the build plate of the 3d printer.
What types of FDM printers exist?
Cartesian 3D Printers
Cartesian 3D Printers
Cartesian 3D Printers are the most popular FDM 3D Printer in consumer 3D printers and have a box like design. It gets its name “Cartesian” because the build plate moves in the Z axis and the print head moves in the Y axis or X axis similar to a cartesian plane. The benefit of this technology is it's simple design that is “easy” to maintain if it breaks down and it produces detailed prints as it is very precise as it prints layer by layer. The drawback is how slow it 3D prints; cartesian FDM machines are quite slow compared to other types.
Delta 3D Printers
Delta 3D Printers
Delta 3D printers have an extender at the top where the printhead is connected by three “arms” on rails that make a triangle shape, which is where the name delta originates. This type of FDM machine has a stationary build plate which allows this type of 3D printer to create unique objects that a cartesian can’t. The benefit of this design is that, unlike the cartesian design, a delta printer can print objects very quickly but the drawback is that it produces less accurate or detailed prints.
Polar 3D Printers
Polar 3D Printers
The Polar FDM 3D printers are unique because the build plate of the 3D printer spins and the printhead can move along the x or y axis. Rather than using a grid system like a cartesian 3D printer, a polar system uses a circular coordination system. The advantage of this system is it can build large objects in a small space and is more energy efficient as it uses only 3 motors. The drawback is that it is a new technology and is not widely used.
SCARA 3D Printers
SCARA 3D Printers
Scara (Selective Compliance Assembly Robotic Arm) is a 3D printing technology similar to a robotic arm that you would find in an automotive manufacturing plant. This technology is very precise and accurate as it can move in flexible positions to create complex prints. The benefit of this technology is it can produce complex designs as it doesn’t have a fixed build built but the drawback is it is a very new technology and does not produce the best quality of print compared to a cartesian.
What are the advantages and disadvantages of FDM 3D printers?
The advantages of FDM 3D printers is their affordability for consumers as compared to other types of 3D printers. They are also very user friendly and great for beginners getting into 3D printing. There is a large assortment of filaments that can be used which can create objects such as wood or flexible filaments.
The drawback of FDM 3D printers is that these printers don’t produce the best details on the 3D prints leaving the layer lines on the print that requires techniques like sanding to make prints smooth. Also most FDM printers require support, which can be a hassle when printing complex objects as they have to be added in software and can be hard to remove when the print is done. Furthermore these printers are usually used in home or office environments and aren't powerful enough compared to industrial 3D printers that can print ceramics or glass that can be dangerous.
The Classic: Resin Based Printers
How do they work?
Resin based 3D printers are the oldest technology of 3D printing and becoming more common as these printers are becoming cheaper. They function by using a build platform in a container of resin where a laser or another lighting device creates layers by the light source “drawing” the layers of the print causing the photopolymer resin solidifying or cure. The build platform after each layer rises according to the layer thickness causing additional resin to flow below the solidified printed portion. The printer then uses light in the next cross section of the object building up the object layer on layer until the object is completely finished. There are top-down resin printers where the light source is above the tank where the object is printed facing upwards; these are mostly used in industry for producing very detailed larger scale objects. The bottom-up 3D printers print upside down and are commonly used as consumer desktop resin 3D printers because of their affordability.
What types of resin printers are there?
An SLA printer works by using a vat (a clear container that holds the resin) and a build plate that moves up or down when it is printing. A laser points at the mirror’s galvanometer to direct the light to the correct direction by the mirrors making the laser focus the light upward to the bottom of the vat where the laser cures the resin that continues till all the layers are created. The benefit of the SLA printers is that they produce smooth and great quality prints. The drawback is that the speed of the print decreases when printing an object with a lot of space which can lead to faulty print.
DLP (Digital Light Processing) is another technology resin based printer that uses a digitally projected surface that projects, which makes it much faster than SLA as it uses a DMD (digital micromirror device). Light is projected by using more than hundred mirrors to create a pattern forming the layer forming three-dimensional cubes, known as voxels, on each layer. The advantage of the DLP 3D printers is that it is faster and creates smooth 3D printed objects. The drawback is the print quality decreases for large objects with curved surfaces.
LCD (Liquid Crystal Display) or mSLA(masked Stereolithography) uses an LCD that produces UV light that acts like a cover so only certain pixels to form the layer is achieved. The advantage is the affordability as it uses LCD which are easier to use and cheaper than a laser causing LCD 3d printing to become more common for consumers. mSLA produces smoother surfaces on the 3d printed object and is much faster than SLA printers. The drawback is the LCD displays have a long lifespan which means replacement of the LCD is common.
What are the advantages and disadvantages of resin based 3D printing?
The advantages of resin based 3D printing are the excellent print quality producing really fine details on the objects and smooth surfaces on objects created by an FDM printing can be achieved through sanding over other methods. Resin 3d printers can achieve faster print speeds compared to other 3d printing technologies as the resin based printers use a laser or another light source that moves along predetermined patterns through the resin to form the object. DLP printing is even faster because it cures a whole layer in a solitary step. Consequently resin 3d printers are the preferred choice in fast-paced industries for manufacturing prototypes and causing more consumers to switch from FDM to resin printers for the fast printing.
The drawback of resin printers is the cost of the technology as the printer itself and the resin is quite expensive with the average desktop resin printer costing $1000-$3000. In comparison, the average FDM printer only costs $300. Furthermore the cost of the liquid resin is quite expensive because several liters are required to fill the resin vat while a spool of cheap PLA or ABS filament can cost $5-25. Also there is an expense related to post processing because removing support structures is a very messy process that requires gloves and plastic sheets are required to remove the extra resin with isopropyl alcohol.
The Industrial Printer: Selective Laser Sintering
How does it work?
SLS (Selective Laser Sintering) 3D printers is the common type of 3D printer used in industrial based environments. This 3D printer uses a laser to sinter particles of thermoplastic polymer powder building a layer to form the object. This printer uses a powder bin filled with polymer powder and is heated just below its melting point. The re-coater creates a thin layer on the build platform by depositing the powder to form a layer by using a diode where it selectively induces fusion between particles to form a solid. The galvenator then moves the laser to a certain point to build a pattern to make the cross-sectional area of the layer solid. Unlike FDM or SLA, SLS doesn’t need support as the unsolidified powder can be used as a support for the 3D print while the object is printing. When the print is completed, the excess powder needs to be removed off the object where the powder is by media using a sandblaster or compressed air or media tumbling to take away the grainy surface. The material used for SLS printers to print objects is Polyamide(nylon) powder which can cost on average between $50–$60 per kilogram and comes in different materials that may have different properties such as elasticity.
What are the advantages and disadvantages of SLS 3D printing?
The advantage of SLS printing is that it is good for printing prototypes as most of the materials have good mechanical properties testing prototype products without manufacturing. Another benefit of SLS printers is that no support is needed ro print out complex objects, which FDM and SLA printers need during the printing process as the unsolidified powder can be used as a support and can be reused.
The drawback is that most SLS 3D printers are industrial printers and are out of the range of many consumers to purchase because of this technologies such as FDM or resin printers have made a foothold with consumers. SLS printers have issues with printing objects that have flat surfaces or holes; this causes prints to warp, producing less accurate details. Compared to other 3D printing technologies extra processing may be required on the object the print may have grainy surfaces that may need to be landed as well as cleaning off excess powder.
Be sure to look for my next column where I will discuss what 3D printers can create.
Works Cited
Carolo, Lucas. "3D Printed Food: All You Need to Know in 2021." https://all3dp.com, All3DP, 22 Nov. 2021, all3dp.com/2/3d-printed-food-3d-printing-food/. Accessed 2 Jan. 2022.
Creality. "The Introductory Guide on FDM 3D Printing." https://www.creality.com, Creality, www.creality.com/blog-detail/the-introductory-guide-on-fdm-3d-printing. Accessed 2 Jan. 2022.
Formlabs. "Guide to Selective Laser Sintering (SLS) 3D Printing." https://formlabs.com, Formlabs, formlabs.com/blog/what-is-selective-laser-sintering/. Accessed 14 Jan. 2022.
---. "Guide to Stereolithography (SLA) 3D Printing." https://formlabs.com, Formlabs, formlabs.com/blog/ultimate-guide-to-stereolithography-sla-3d-printing/. Accessed 14 Jan. 2022.
Fortuna, Carolyn. "3D-Printed Houses — The Future Of Construction? (Video)." https://cleantechnica.com, CleanTechnica, 14 Jan. 2022, cleantechnica.com/2022/01/14/3d-printed-houses-the-future-of-construction-video/. Accessed 18 Jan. 2022.
MakerBot. "LEARN EVERYTHING YOU NEED TO KNOW ABOUT THE HISTORY OF 3D PRINTING." https://www.makerbot.com, Makerbot, www.makerbot.com/stories/engineering/history-of-3d-printing/. Accessed 2 Jan. 2022.
Protolabs. "Selective Laser Sintering (SLS)." https://www.protolabs.com, Protolabs, www.protolabs.com/services/3d-printing/selective-laser-sintering/. Accessed 15 Jan. 2022.
---. "Stereolithography (SLA)." https://www.protolabs.com, Protolabs, www.protolabs.com/services/3d-printing/stereolithography/. Accessed 22 Jan. 2022.
Tower Fasteners. "How Will 3D Printing Change The Manufacturing Industry?" https://www.towerfast.com, Tower Fasteners, www.towerfast.com/press-room/how-will-3d-printing-change-the-manufacturing-industry. Accessed 14 Jan. 2022.
Turney, Drew. "History of 3D Printing: It's Older Than You Think." https://redshift.autodesk.com, Autodesk, 31 Aug. 2021, redshift.autodesk.com/history-of-3d-printing/. Accessed 2 Jan. 2022.
Varotsis, Alkaios Bournias. "What is FDM 3D printing?" https://www.hubs.com, Hubs, www.hubs.com/knowledge-base/what-is-fdm-3d-printing/. Accessed 2 Jan. 2022.
---. "What is SLA 3D printing?" https://www.hubs.com, hubs, www.hubs.com/knowledge-base/what-is-sla-3d-printing/. Accessed 16 Jan. 2021.
---. "What is SLS 3D printing?" https://www.hubs.com, Hubs, www.hubs.com/knowledge-base/what-is-sls-3d-printing/. Accessed 17 Jan. 2022.
Page layout by Sara Rastin
Page updated
Report abuse