3D printingFrom Wikipedia, the free encyclopediaFor methods of applying a 2-D image on a 3-D surface, see Pad printing. For methods of printing 2-Dparallax stereograms that seem 3-D to the eye, see lenticular printing and holography.A 3D printer.Timelapse video of a hyperboloid object print (made of PLA) using a RepRap “Prusa Mendel” 3D printer for moltenpolymer deposition. Part of a series on the History of printing
• Woodblock printing (200) • Movable type (1040) • Printing press (1454) • Etching (ca. 1500) • Mezzotint (1642) • Aquatint (1768) • Lithography (1796) • Chromolithography (1837) • Rotary press (1843) • Offset printing (1875) • Hectograph (19th century) • Hot metal typesetting (1886) • Mimeograph (1890) • Screen printing (1907) • Spirit duplicator (1923) • Dye-sublimation (1957) • Phototypesetting (1960s) • Dot matrix printer (1964) • Laser printing (1969) • Thermal printing (ca. 1972) • Inkjet printing (1976) • Stereolithography (1986) • Digital press (1993) • 3D printing (ca. 2003) V T E3D printing or additive manufacturing is a process of making three dimensional solid objects froma digital file. 3D printing is achieved using additive processes, where an object is created by layingdown successive layers of material. 3D printing is considered distinct from traditionalmachining techniques (subtractive processes) which mostly rely on the removal of material by drilling,cutting etc.
3D printing is usually performed using a materials printer, and since 2003 there has been large growthin the sales of these machines. Additionally, the cost of 3D printers has gone down.  The technologyalso finds use in the fields of jewelry, footwear, industrial design, architecture, engineering andconstruction (AEC), automotive, aerospace, dental and medical industries, education, geographicinformation systems, civil engineering, and many others. Contents [hide] 1 Terminology 2 General principles 3 Technologies 4 Methodso 4.1 Molten polymer depositiono 4.2 Granular materials bindingo 4.3 Photopolymerization 5 Resolution 6 Applicationso 6.1 Research into new applicationso 6.2 Industrial uses 6.2.1 Rapid prototyping 6.2.2 Rapid manufacturingo 6.3 Domestic and hobbyist uses 6.3.1 Printers for domestic useo 6.4 Printers for commercial and domestic use 7 3D printing services 8 History 9 Exhibits 10 See also 11 References 12 Bibliography 13 Further reading 14 External linksTerminology
Additive manufacturing (AM) also known as 3D printing is defined by ASTM as the "process of joiningmaterials to make objects from 3D model data, usually layer upon layer, as opposed to subtractivemanufacturing methodologies, such as traditional machining. Synonyms include additivefabrication, additive processes, additive techniques, additive layer manufacturing, layermanufacturing and freeform fabrication".The term additive manufacturing describes technologies which can be used anywhere throughout theproduct life cycle from pre-production (i.e. rapid prototyping) to full scale production (also knownas rapid manufacturing) and even for tooling applications or post production customisation.General principles3D model slicingThe use of additive manufacturing takes virtual designs from computer aided design (CAD)or animation modeling software, transforms them into thin, virtual, horizontal cross-sections and thencreates successive layers until the model is complete. It is a WYSIWYG process where the virtualmodel and the physical model are almost identical.With additive manufacturing, the machine reads in data from a CAD drawing and lays downsuccessive layers of liquid, powder, or sheet material, and in this way builds up the model from aseries of cross sections. These layers, which correspond to the virtual cross section from the CADmodel, are joined together or fused automatically to create the final shape. The primary advantage toadditive fabrication is its ability to create almost any shape or geometric feature.The standard data interface between CAD software and the machines is the STL file format. An STLfile approximates the shape of a part or assembly using triangular facets. Smaller facets produce ahigher quality surface. VRML (or WRL) files are often used as input for 3D printing technologies thatare able to print in full color.
Construction of a model with contemporary methods can take from several hours to several days,depending on the method used and the size and complexity of the model. Additive systems cantypically produce models in a few hours, although it can vary widely depending on the type of machinebeing used and the size and number of models being produced simultaneously.Some additive manufacturing techniques use two materials in the course of constructing parts. Thefirst material is the part material and the second is the support material (to support overhangingfeatures during construction). The support material is later removed by heat or dissolved away with asolvent or water.Traditional injection molding can be less expensive for manufacturing polymer products in highquantities, but additive fabrication can be faster and less expensive when producing relatively smallquantities of parts. 3D printers give designers and concept development teams the ability to produceparts and concept models using a desktop size printer.TechnologiesRapid prototyping worldwideThe Audi RSQ was made by Audi with rapid prototyping industrial KUKA robotsThere are several technologies. All those available as of 2012 were additive, differing mainly in theway layers are built to create parts. Some melt or soften material to produce layers (SLS, FDM), whileothers lay liquid materials thermosets that are cured with different technologies. Lamination systemscut thin layers to shape and join them together.As of 2005 conventional additive rapid prototype machines cost around £25,000. 
Additive technologies Base materialsSelective laser sintering (SLS) Thermoplastics, metals powders, ceramic powdersDirect metal laser sintering (DMLS) Almost any alloy metalFused deposition modeling (FDM) Thermoplastics, eutectic metalsStereolithography (SLA) photopolymerLaminated object manufacturing (LOM) Paper, foil, plastic filmElectron beam melting (EBM) Titanium alloysPowder bed and inkjet head 3d printing Plaster, Colored PlasterPlaster-based 3D printing (PP)MethodsA number of competing technologies are available to do 3D printing. Their main differences are foundin the way layers are built to create parts. Some methods use melting or softening material to producethe layers, e.g. selective laser sintering (SLS) and fused deposition modeling (FDM), while others layliquid materials that are cured with different technologies, i.e. stereo lithography (SLA). In the case oflaminated object manufacturing (LOM), thin layers are cut to shape and joined together (i.e. paper,polymer, metal). Each method has its advantages and drawbacks, and consequently some companiesoffer a choice between powder and polymer as the material from which the object emerges. Generally, the main considerations are speed, cost of the printed prototype, cost of the 3D printer,choice and cost of materials and colour capabilities. Molten polymer deposition
Fused deposition modeling: 1 - nozzle ejecting molten plastic, 2 - deposited material (modeled part), 3 - controlledmovable tableFused deposition modeling (FDM) is a technology developed by Stratasys in the late 1980s and wascommercialized in 1990 which is used in traditional rapid prototyping,FDM works using a plastic filament or metal wire which is unwound from a coil and supplies material toan extrusion nozzle which can turn the flow on and off. The nozzle is heated to melt the material andcan be moved in both horizontal and vertical directions by a numerically controlled mechanism, directlycontrolled by a computer-aided manufacturing (CAM) software package. The model or part isproduced by extruding small beads of thermoplastic material to form layers as the material hardensimmediately after extrusion from the nozzle. Stepper motors or servo motors are typically employed tomove the extrusion head.The molten polymer used is often Acrylonitrile butadiene styrene (ABS),Polycarbonate (PC), Polylacticacid (PLA), PC/ABS, Polyphenylsulfone(PPSU), Ultem 9085 etc.Granular materials bindingLike most granular systems CandyFab fuses parts of the layer, and then moves the working area downwards, andthen adds another layer of granules and then repeats the process until the piece has built up
Another approach is selective fusing of print media in a granular bed. In this variation, the unfusedmedia serves to support overhangs and thin walls in the part being produced, reducing the need forauxiliary temporary supports for the workpiece. Typically a laser is used to sinter the media and formthe solid. Examples of this are selective laser sintering(SLS), using metals as well as polymers (i.e.PA, PA-GF, Rigid GF, PEEK, PS, Alumide, Carbonmide, elastomers), and direct metal lasersintering (DMLS).Electron beam melting (EBM) is a similar type of additive manufacturing technology for metal parts(i.e. titanium alloys). EBM manufactures parts by melting metal powder layer by layer with an electronbeam in a high vacuum. Unlike metal sintering techniques that operate below melting point, the partsare fully dense, void-free, and very strong.The CandyFab printing system uses heated air and granulated sugar. It can be used to produce food-grade art objects.Another method consists of an inkjet 3D printing system. The printer creates the model one layer at atime by spreading a layer of powder (plaster, or resins) and inkjet printing a binder in the cross-sectionof the part. The process is repeated until every layer is printed. This technology allows for the printingof full colour prototypes and allows overhangs, as well as elastomer parts. Bonded powder prints canbe further strengthened by wax or thermoset polymer impregnation.PhotopolymerizationStereolithography apparatusThe main technology in which photopolymerization is used to produce a solid part from a liquidis stereolithography (SLA).In digital light processing (DLP), a vat of liquid polymer is exposed to light from a DLP projectorunder safelight conditions. The exposed liquid polymer hardens. The build plate then moves down insmall increments and the liquid polymer is again exposed to light. The process repeats until the model
is built. The liquid polymer is then drained from the vat, leaving the solid model. The ZBuilder Ultra isan example of a DLP rapid prototyping system.The Objet PolyJet system uses an inkjet printer to spray photopolymer materials in ultra-thin layers (16micron) layer by layer onto a build tray until the part is completed. Each photopolymer layer is cured byUV light immediately after it is jetted, producing fully cured models that can be handled and usedimmediately, without post-curing. The gel-like support material, which is designed to supportcomplicated geometries, is removed by hand and water jetting. Also suitable for elastomers.Ultra-small features may be made by the 3D microfabrication techniqueof multiphoton photopolymerization. In this approach, the desired 3D object is traced out in a block ofgel by a focused laser. The gel is cured to a solid only in the places where the laser was focused,because of the nonlinear nature of photoexcitation, and then the remaining gel is washed away.Feature sizes of under 100 nm are easily produced, as well as complex structures such as moving andinterlocked parts.Yet another approach uses a synthetic resin that is solidified using LEDs.ResolutionResolution is given in layer thickness and X-Y resolution in dpi. Typical layer thickness isaround 100 micrometres(0.1 mm), although some machines such as the Objet Connex series can printlayers as thin as 16 micrometres. X-Y resolution is comparable to that of laser printers. The particles(3D dots) are around 50 to 100 micrometres (0.05-0.1 mm) in diameter.In some cases the printing method is able to deliver sufficient resolution for the application, but inmany cases some extra work is required to shape the surface accurately or give a suitable finish byremoving excess material (subtractive process).Applications Three-dimensional printing makes “ it as cheap to create single items as it is to produce thousands and thus undermineseconomies of scale. It may have as profound an impact on the world as the coming of the factory did....Just as nobody could have predicted the impact of the steam engine in 1750—or the printing press in 1450, or thetransistor in 1950—it is impossible to foresee the long- term impact of 3D printing. But the technology is coming, and it is ”
likely to disrupt every field it touches. —The Economist, in a February 10, 2011 leaderA model (left) was digitally acquired by using a3D scanner, the scanned data processed usingMeshLab, and theresulting 3D model used by arapid prototyping machine to create a resin replica (right)An example of 3D printed limited editionjewellery. This necklace is made of glassfiber-filled dyed nylon. It hasrotating linkages that were produced in the same manufacturing step as the other parts. Photography: Atelier TedNoten.Standard applications include design visualization, prototyping/CAD, metal casting, architecture,education, geospatial, healthcare and entertainment/retail.Research into new applicationsOther applications would include reconstructing fossils in paleontology, replicating ancient andpriceless artifacts in archaeology, reconstructing bones and body parts in forensicpathology andreconstructing heavily damaged evidence acquired from crime scene investigations.
In 2007 the use of 3D printing technology for artistic expression was suggested.  Artists have beenusing 3D printers in various ways.  During the 2011 London Design Festival, an installation, curatedby Murray Moss and focused on 3D Printing, took place in the Victoria and Albert Museum (the V&A).The installation was called Industrial Revolution 2.0: How the Material World will Newly Materialise. As of 2012 3D printing technology was being studied by biotechnology firms and academia forpossible use in tissue engineering applications where organs and body parts are built using inkjettechniques. Layers of living cells are deposited onto a gel medium and slowly built up to form threedimensional structures. Several terms have been used to refer to this field of research: organ printing,bio-printing, and computer-aided tissue engineering, among others. 3D printing can produce apersonalized hip replacement in one pass, with the ball permanently inside the socket; at availableprinting resolutions the unit does not require polishing.A proof-of-principle project at the University of Glasgow, UK, in 2012 has shown that it is possible touse 3D printing techniques to create chemical compounds, including new ones. They first printbespoke chemical reaction vessels, then use the printer to squirt reactants into them as "chemicalinks" which then react. They have produced new compounds to verify the validity of the process,although not seeking anything with a particular application . They used the Fab@Home open sourceprinter, at a stated cost of US$2,000.The use of 3D scanning technologies allow the replication of real objects without the useof molding techniques, that in many cases can be more expensive, more difficult, or too invasive to beperformed; particularly with precious or delicate cultural heritage artifacts where the direct contact ofthe molding substances could harm the surface of the original object. Even a smartphone can be usedas 3D scanner: at the 2012 Consumer Electronics Show, Sculpteo unveiled a mobile app that allowsa 3D file to be generated directly with a smartphone.Industrial usesRapid prototypingMain article: rapid prototypingIndustrial 3D printers have existed since the early 1980s, and have been used extensively for rapidprototyping and research purposes. These are generally larger machines that use proprietarypowdered metals, casting media (i.e., sand), plastics or cartridges, and are used for many rapidprototyping uses by universities and commercial companies. Industrial 3D printers are made bycompanies such asExOne, Objet Geometries, Stratasys, 3D Systems, EOS GmbH, and Z Corporation.Rapid manufacturing
Rapid manufacturing is a new method of manufacturing, with many of its processes still unproven.Some of the most promising processes are adaptations of well established rapid prototyping methodssuch as laser sintering (LS). However, due to the immaturity of 3D printing, these techniques are stillvery much in their infancy. Advances in RP technology have brought about the ability to usematerials that are appropriate for final manufacture. These advances in material use have broughtabout the prospects of directly manufacturing finished components, however, many obstacles still needto be overcome before AM can be considered as a realistic manufacturing choice.3D printing is now entering the field of rapid manufacturing and it is believed by many experts that thisis a "next level" technology.The advantages of 3D printing in rapid manufacturing lie in the relativelyinexpensive production of small numbers of parts.Domestic and hobbyist uses This section requires expansion.Domestic 3D printing is mainly for hobbyists and enthusiasts as of 2012, rather than practicalhousehold applications. Designs such as a working clock have been made, not as a practical, orparticularly accurate timepiece, but as an interesting project . Gears have been printed for homewoodworking machines and other purposes. 3D printing is also used for ornamental objects. Oneprinter (the Fab@Home) makes a point of including chocolate amongst the materials that can beprinted. Web sites associated with 3D printing tend to include backscratchers, coathooks, and so on.The RepRap Web site included such examples, but was badly out of date in May 2012. TheFab@Home gallery had many objects without practical application, but included examples of what ispossible such as a flashlight/torch using conductive ink for the electrical circuit, a battery-powered motor, a case for an iPod, a silicone watch band, and a translucent cylinder completelyenclosing a brown box, something difficult to fabricate any other way .The open source Fab@Home project has developed printers for general use. They have been usedin a research environment to produce chemical compounds with 3D printing technology, including newones, initially without immediate application as proof of principle . The printer can print with anythingthat can be dispensed from a syringe as liquid or paste. The developers of the chemical applicationenvisage that this technology could be used both in industry and for domestic use, so that "people infar-flung regions could make their own headache pills or detergent. The technique might also allowpeople to print and share recipes for niche substances that chemical or pharmaceutical companiesdont make – because there arent enough customers, or they simply havent dreamed up thoseideas."Printers for domestic use
RepRap version 2.0 (Mendel)MakerBot Cupcake CNC
Airwolf 3D AW3D v.4 (Prusa)There are several projects and companies making efforts to develop 3D printers suitable for desktopuse at a price many households can afford, many of which are related. Much of this work was drivenby and targeted to DIY/enthusiast/early adoptercommunities, with links to both the academicand hacker communities.The RepRap is a one of the longest running projects in the Desktop category. The RepRap projectaims to produce a free and open source software (FOSS) 3D printer, whose full specifications arereleased under the GNU General Public License, and which can print many of its own parts (theprinted parts) to create more machines. As of November 2010, the RepRap can print plastic parts, andrequires motors, electronics, and some metal support rods to be completed.  Research isunder way to enable the device to print circuit boards, as well as metal parts. Several companies andindividuals sell parts to build various RepRap designs, the average price of a RepRap printer kit being€400 (US$537).Because of the FOSS aims of RepRap, many related projects have used their design for inspiration,creating an ecosystem of many related or derivative 3D printers, most of which are also Open Sourcedesigns. The availability of these open source designs means that variants of 3D printers are easy toinvent; however, the quality and complexity of various printer designs, as well as the quality of kit orfinished products, varies greatly from project to project. These printers include the Airwolf 3D,fabbster, MakerBot Industries Thing-O-Matic, Ultimaker, Solidoodle 2, Shapercube, Mosaic, Prusa andHuxley 3D printers. This rapid development of open source 3D printers is gaining interest in both thedeveloped as well as the developing world as it enables both hyper-customization and the use ofdesigns in the public domain to fabricate open source appropriate technology through conduits such
as Thingiverse. This technology can also assist in sustainable development as such technologies areeasily and economically made from readily available resources by local communities to meet theirneeds.The open source Fab@Home project has developed printers for general use which can use anythingsquirtable through a nozzle, from chocolate to silicon sealant and chemical reactants. Printers to theprojects designs were available from suppliers in kit or assembled form at prices in the region ofUS$2000 as of 2012.Many of these printers are available in kit form, and some are available fully assembled. TheSolidoodle 2, a 6x6x6 inch printer is available fully assembled for US$499. Prices of printer kits varyfrom US$350 for the open source SeeMeCNC H-1, US$500 for the Printrbot, both derived fromprevious RepRap models, to US$2000 for the Makerbot Replicator (dual-extruder edition) which printseither two colors or abs/pla and a water-soluble support material. Printers for commercial and domestic useThe development and hyper-customization of the RepRap-based 3D printers has produced a newcategory of printers suitable for both domestic and commercial use. The Airwolf 3D AW3D v.4 isa RepRap-based machine, descended from the Prusa design and enhanced to print at high speed andhigh definition. The cost of an assembled and calibrated Airwolf 3D printer (model AW3D.v.4) isapproximately US$1600. Depending on application, the degree of printing resolution and speed ofmanufacturing lies between a personal printer and an industrial printer. The AW3D operates on opensource appropriate technology software.3D printing servicesSome companies offer an on-line 3D printing service open both to consumers and to industry.  People upload their own 3D designs to a 3D printing service company website, designs are printedvia industrial 3D printers and then shipped to the customer.Some examples of 3D printing servicescompanies are Shapeways , Kraftwurx, i.materialise and Freedom Of Creation. Thingiverse of MakerBot Industries allows the sharing of 3D printing files and serves as a communityresource.HistoryIn the history of manufacturing, and most especially of machining, subtractive methods have oftencome first. In fact, the term "subtractive manufacturing" is a retronym developed in recent years todistinguish traditional methods from the newer additive manufacturing techniques.Although fabrication has included methods that are essentially "additive" for centuries (such as joining
plates, sheets, forgings, and rolled work via riveting, screwing, forge welding, or newer kinds ofwelding), it did not include theinformation technology component of model-based definition; and theprovince of machining (generating exact shapes with high precision) was generally a subtractive affair,from filing and turning through milling and grinding. For example, an encyclopedia article on threadingtoday mentions both additive and subtractive methods as well as various integrations of the two,whereas an article on the same topic 20 years ago would not have contained the words "additive" and"subtractive" and would probably not have mentioned any additive techniques at all (let alone namingand differentiating them via use of those labels).Additive manufacturings earliest applications have been on the toolroom end of the manufacturingspectrum. For example, rapid prototyping was one of the earliest additive variants, and its mission wasto reduce the lead time and cost of developing prototypes of new parts and devices, which was earlieronly done with subtractive toolroom methods (typically slowly and expensively).  However, as theyears go by and technology continually advances and disseminates into the business world, additivemethods are moving ever further into the production end of manufacturing—sometimes even in waysthat the pioneers of the techniques didnt foresee.  Parts that formerly were the sole province ofsubtractive methods can now in some cases be made more profitably via additive ones. However, thereal integration of the newer additive technologies into commercial production is essentially a matter ofcomplementing subtractive methods rather than displacing them entirely.  Predictions for the future ofcommercial manufacturing, starting from todays already-begun infancy period, are that manufacturingfirms will need to be flexible, ever-improving users of all available technologies in order to remaincompetitive.It is also predicted by some additive manufacturing advocates that this technological development arcwill change the nature of commerce, because end users will be able to do much of their ownmanufacturing rather than engaging in trade to buy products from other people and corporations. [citationneeded]ExhibitsBetween 2011 and 2012 a 3D printing focused exhibit was held at Disseny Hub Barcelona. It wascalled Full Print3d. Printing Objects.The permanent exhibition, Full Print3d. Printing objects providedan introduction to digital fabrication through a series of projects that illustrate the conceptualimplications of this type of production for design.See also Design portal
Additive Manufacturing File Format List of common 3D test models List of emerging technologies Self-replicating machine Desktop manufacturing Digital fabricator Direct digital manufacturing Laser claddingReferences 1. ^ a b The engineer: The rise of additive manufacturing 2. ^ Create It Real. "3D Printer Technology - Animation of layering (CreateItReal.com)". Retrieved 2012-01-31. 3. ^ Lilli Manolis Sherman. "3D Printers Lead Growth of Rapid Prototyping (Plastics Technology, August 2004)". Retrieved 2012-01-31. 4. ^ Reprinted, with permission, from ASTM F2792-10 Standard Terminology for Additive Manufacturing Technologies, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard can be obtained from ASTM International, http://www.astm.org . 5. ^ D. T. Pham, S. S. Dimov, Rapid manufacturing, Springer-Verlag, 2001, ISBN 1-85233- 360-X, page 6 6. ^ http://www.bath.ac.uk/pr/releases/replicating-machines.htm 7. ^ Lilli Manolis Sherman (2007-11-15). "A whole new dimension - Rich homes can afford 3D printers (The Economist, November 15, 2007)". Retrieved 2012-01-31. 8. ^ Terry Wohlers. "Factors to Consider When Choosing a 3D Printer (WohlersAssociates.com, Nov/Dec 2005)". Retrieved 2012-01-31.