Those encountering a 3D printer in the world for the first time. Often ask me what is 3D printing, and how does 3D printing work? But a more helpful question might be which machine is that and which 3D printing technology does it use? Remember that 3D printing is a generalized term for everything under the additive manufacturing umbrella. The label itself doesn't actually clarify the substance, shape, or method of fabrication used by a specific device. It's a foggy phrase for a manufacturing robot that produces physical objects from digital files. The terms 3D printing and the industry preferred label of additive manufacturing group together a family of diverse, even distant fabrication processes. So many than few users will encounter all of them in the course of a single project, job, or even career. Thus from a practical perspective, the individual designer, engineer, or small business owner has a direct experience of only handful of the range of AM types. With an ever-growing menu of specialized materials, specific strategies available through the use of fabrication service bureaus and factories. The other videos in this specialization have highlighted a number of the Industrial as well as desktop printing technologies. In this video, we will focus attention on the ones you're more likely to use, providing the background contexts along the way for our focus elsewhere in this course on Fused filament fabrication desktop 3D printing technologies. Depending on the week you check, there are between eight and 15 major forks of the unruly Amazonian river of additive manufacturing technologies. There isn't consensus on whether some of these deserved to be labeled as major versus minor branches. Whether some of these frequently, including several lists, are oxbow puddles no longer spring fed by the main force of history and progress in this field. As we discussed, in the previous lecture, the additive manufacturing 3D printing field is in it's early thirty's and has already provided fertile grounds for thousands of patents in hundreds of thousands of inventors. There are many ways to categorize the various processes currently lumped into 3D printing. But the most popular or at least the most frequently discussed force of the added manufacturing river are the following seven core technologies. Extrusion based, that photo polarization, Powder-bed fusion, direct energy deposition, binder jetting, material jetting, and sheet lamination. Each of the 3D printing commercial technologies approached the central idea for how to fabricate parts from a digital design file and computer-guided technology on their own terms and with their own customers and unique market opportunities driving development and associated process costs. Despite the promises of 3D printing established by the Star Trek Replicator and other conceptual ideas about 3D printing, this field hasn't really delivered up a pure general-purpose technology yet. Let's now talk about the desktop bench-top technologies in specific and leave out the industrial processes for now. You can read more about the other Additive Manufacturing Processes in the materials for this course. I'm going to use the terms stuff and thing in these descriptions to avoid limiting your sense of what types of materials can be used and what types of parts can be produced. One, extrusion-based. Under this, you have Fused Deposition Modeling FDM, Fused Filament Fabrication FFF, paste extrusion, Robo casting, produce a gel or heat stuff up so that it can be delivered via Control squirt onto a build plate building up a thing layer by layer drawing a tall stack of very thin two-dimensional cross-sections. FFF is like a hot glue gun guided by the hands of a clever patient robot and paste extrusion more like the same thing but being done with cake frosting instead. Two, that photo-polymerization, stereo-lithography SLA, digital light processing DLP. Flash energy onto photo-curable liquid stuff via laser or optical projector, building up a thing through thin film after film of cured material cured and fuse to the next layer. Three, powder-bed fusion. Within that, you have Selective laser sintering SLS, Selective heat sintering SHS. A thin layer of powdered material is laid down, and machine uses heat and or lasers to bind a layer of a thing by fusing together finely ground powdered stuff. Sintering referring to a process of applying just enough heat and energy to fuse a powdered stuff particles together right in place so that more layers can be fused over-top the original layers a little bit different than welding. More processes are folding into and out of this list all the time, learning the basics for each function. When broad patents on core technologies will expire may help telegraph the direction for the next ground-breaking innovation. All these are the hottest affordable fabrication technology for the desktop market or any of the applied versions of this technology truly that pure and distinct from each other? Not really, because clever innovations that can be generally applied available manufacturing materials, design, and analysis software and a new specific application for this technology encouraged the blurring of boundaries and the pillaging of handy ideas to meet immediate needs. As a result, the entire territory has not been fully explored, and no one really knows everything that is possible. What's more, in a Venn diagram of digital fabrication technologies, 3D printing overlaps with many other methods, especially those either relying on Computer-guided tools or optimized with microprocessor unit Automation in the past century. Broadening the potential field of Machine Design, Process Control Automation, Robotics, and manufacturing technologies that are the true natural springs that feed these technologies. I suggest you don't spend too much energy worrying about how to delineate each pure approach and the nomenclature pen to it. In the time that I've been preparing this course admittedly a long time in three printing years. Two of the approaches I intended to discuss a greater length here have basically fallen completely out of use with a few new unique zero-gravity techniques now joining the industrial ones, and a few of the technologies I described as never coming to desktop are actually going to shape desktop products in 2020. How well we live in exciting times. If you're curious about additional AM technologies that are making their way to desktop or service bureaus such as the rival of Desktop Metal and SLS, New SLA DLP variance, and hybrid techniques in use in research that seem likely to reach commercialization soon. Please see the additional resources I have shared online.