Abstract on 3d printing
3d printing for dummies...
ABSTRACT SEMINAR ON 3D PRINTING What is a 3D printer? 3D printers are a new generation of machines that can make everyday things. They’re remarkable because they can produce different kinds of objects, in different materials, all from the same machine. A 3D printer can make pretty much anything from ceramic cups to plastic toys, metal machine parts, stoneware vases, fancy chocolate cakes or even (one day soon) human body parts. They replace traditional factory production lines with a single machine; just like home inkjet printers replaced bottles of ink, a printing press, hot metal type and a drying rack. 3D printing is a type of additive manufacturing technology where a three dimensional object is made by laying down successive layers of material which forms the final object.3D printers offer product designers the ability to print parts and components that are made from different materials which have various mechanical and physical properties in a single build process. The more advanced 3D printing technologies currently yield models that closely emulate the appearance and functionality of the final product. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes.3D printing is also considered distinct from traditional machining techniques, which mostly rely on the removal of material by methods such as cutting or drilling (subtractive processes). A materials printer usually performs 3D printing processes using digital technology. The first working 3D printer was created in 1984 by Chuck Hull of 3D Systems Corp. Since the start of the 21st century there has been a large growth in the sales of these machines, and their price has dropped substantially. According to Wohlers Associates, a consultancy, the market for 3D printers and services was worth $2.2 billion worldwide in 2012, up 29% from 2011. The 3D printing technology is used for both prototyping and distributed manufacturing with applications in architecture, construction (AEC), industrial design, automotive, aerospace, military, engineering, civil engineering, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry, eyewear, education, geographic information systems, food, and many other fields. It has been speculated that 3D printing may become a mass market item because open source 3D printing can easily offset their capital costs by enabling consumers to avoid costs associated with purchasing common household objects. Why is it called printing? If you look closely (with a microscope) at a page of text from your home printer, you’ll see the letters don’t just stain the paper, they’re actually sitting slightly on top of the surface of the page. In theory, if you printed over that same page a few thousand times, eventually the ink would build up enough layers on top of each other to create a solid 3D model of each letter. That idea of building a physical form out of tiny layers is how the first 3D printers worked. How does a 3d printer work? A 3D printer works by taking a 3D computer file, from industry standard software, such as AutoCad and Maya, and then computing a large number of cross-sectional slices. Various phases of 3-d printing mechanism are:
Modeling Additive manufacturing takes virtual blueprints from computer aided design (CAD) or animation modeling software and "slices" them into digital cross-sections for the machine to successively use as a guideline for
printing. Depending on the machine used, material or a binding material is deposited on the build bed or platform until material/binder layering is complete and the final 3D model has been "printed."A standard data interface between CAD software and the machines is the STL file format. An STL file approximates the shape of a part or assembly using triangular facets. Smaller facets produce a higher quality surface. PLY is a scanner generated input file format, and VRML (or WRL) files are often used as input for 3D printing technologies that are able to print in full color.
Printing To perform a print, the machine reads the design from an .stl file and lays down successive layers of liquid, powder, paper or sheet material to build the model from a series of cross sections. These layers, which correspond to the virtual cross sections from the CAD model, are joined or automatically fused to create the final shape. The primary advantage of this technique is its ability to create almost any shape or geometric feature. Printer resolution describes layer thickness and X-Y resolution in dpi (dots per inch), or micrometers. Typical layer thickness is around 100 micrometers (µm), although some machines such as the Objet Connex series and 3D Systems' ProJet series can print layers as thin as 16 µm. X-Y resolution is comparable to that of laser printers. The particles (3D dots) are around 50 to 100 µm in diameter. Construction of a model with contemporary methods can take anywhere from several hours to several days, depending on the method used and the size and complexity of the model. Additive systems can typically reduce this time to a few hours, although it varies widely depending on the type of machine used and the size and number of models being produced simultaneously. Traditional techniques like injection molding can be less expensive for manufacturing polymer products in high quantities, but additive manufacturing can be faster, more flexible and less expensive when producing relatively small quantities of parts. 3D printers give designers and concept development teams the ability to produce parts and concept models using a desktop size printer.
Finishing Though the printer-produced resolution is sufficient for many applications, printing a slightly oversized version of the desired object in standard resolution, and then removing material with a higher-resolution subtractive process can achieve greater precision. Some additive manufacturing techniques are capable of using multiple materials in the course of constructing parts. Some are able to print in multiple colors and color combinations simultaneously. Some also utilize supports when building. Supports are removable or dissolvable upon completion of the print, and are used to support overhanging features during construction.
What are the opportunities? Have you ever broken something, only to find it’s no longer sold and you can’t replace it? 3D printing means you can simply print a new one. That world, where you can make almost anything at home, is very different from the one we live in today. It’s a world that doesn’t need lorries to deliver goods or warehouses to store them in, where nothing is ever out of stock and where there is less waste, packaging and pollution. It’s also a world where everyday items are made to measure, to your requirements. That means furniture made to fit your home, shoes made to fit your feet, door handles made to fit your hand, meals printed to your tastes at the touch of a button. Even medicines, bones, organs and skin made to treat your injuries. You can get some of those things now if you’re wealthy, but 3D printing brings affordable, bespoke manufacturing to the masses. If that sounds like pure fantasy, try googling “personalised 3D printed products” and see for yourself. After all, the notion of doing your supermarket shopping on an iPad was like something out of Star Trek 20 years ago.
Instantly printing parts and entire products, anywhere in the world, is a game changer. But it doesn’t stop there. 3D printing will affect almost every aspect of industry and our personal lives. Medicine will forever be changed as new bioprinters actually print human tissue for both pharmaceutical testing and eventually entire organs and bones. Architecture and construction are changing as well. Now, 3D-printed models of complex architectural drawings are created quickly and inexpensively, rather than the expensive and time-consuming process of handcrafting models out of cardboard. And experimental, massive 3D printers are printing concrete structures, with the goal of someday creating entire buildings with a 3D printer.Art is already forever changed. Digital artists are creating magnificent pieces that seem almost impossible to have been made by traditional methods. From sculptures to light fixtures, beautiful objects no longer need to be handcrafted, just designed on a computer. And there are developments where you least expect them: for example, archeologists can 3D scan priceless and delicate artifacts, and then print copies of them so they can handle them without fear of breakage. Replicas can be easily made and distributed to other research facilities or museums. It has been used to create a full-size reproduction of King Tutankhamun’s mummy and to repair Rodin’s sculpture, The Thinker
What are the limitations? Although buying a 3D printer is much cheaper than setting up a factory, the cost per item you produce is higher, so the economics of 3D printing don’t stack-up against traditional mass production yet. It also can’t match the smooth finish of industrial machines, nor offer the variety of materials or range of sizes available through industrial processes. But, like so many household technologies, the prices will come down and 3D printer capabilities will improve over time.
Is it the next big thing? Yes, if you’re a product designer or engineer. Like all new technologies, the industry hype is a few years ahead of the consumer reality. It’s an emerging technology which means, like home computers or mobile phones, most people will remain skeptical about needing one until everyone has got one… and then we’ll all wonder how we ever managed without them. Aryan Singh 2010-ECA-1081 B.Tech ECE(7th semester)