Seminar Report on 3D Printing TechnologiesFor 1 Credit Seminar

Bhargava Venkatesh1PI10EE026

November 20, 2013

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Contents

1 Introduction 31.1 The Rise of 3D Printing . . . . . . . . . . . . . . . . . . . . . 41.2 General Principles . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.2.1 Modeling . . . . . . . . . . . . . . . . . . . . . . . . . 51.2.2 Printing . . . . . . . . . . . . . . . . . . . . . . . . . . 61.2.3 Finishing . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 3D Printing Techniques and Materials 82.1 3D Printing Techniques . . . . . . . . . . . . . . . . . . . . . . 82.2 3D Printing Materials . . . . . . . . . . . . . . . . . . . . . . 10

3 The Future of 3D Printing 133.1 3Doodler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143.2 3D Printed Organs . . . . . . . . . . . . . . . . . . . . . . . . 153.3 3D Printed Food . . . . . . . . . . . . . . . . . . . . . . . . . 16

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Chapter 1

Introduction

The purpose of this document is to provide one with an idea about 3D Print-ing trends and technologies. Additive manufacturing or 3D printing isa process of making a three-dimensional solid object of virtually any shapefrom a digital model. 3D printing is achieved using an additive process,where successive layers of material are laid down in different shapes. 3Dprinting is also considered distinct from traditional machining techniques,which mostly rely on the removal of material by methods such as cutting ordrilling (subtractive processes). 3D printers are used for rapid prototypingwhich involves sending a Computer Aided Design (CAD) to the printer thatis then sliced by a program and printed using a material layer by layer untilthe full shape is formed.

Rapid prototyping does not reproduce models with the same quality andconsistency as conventional prototyping methods. This might not be thecase in the future as more and more industries and sectors are adopting thistechnology and more R& D is being performed on various technologies in 3Dprinting. Also for industries that are design conscious and have time con-straints 3D printing is a better choice.

3D printing uses additive printing technology to print objects in 3D. Theprinter prints 3D models by adding materials like metals, plastics or poly-mers layer by layer over each other until the required 3 dimensional shape isformed. The printers can print with a precision of 0.1 mm or more, givingthe technology to print precise designs with accuracy.

3D printing has already been adopted by industries like aerospace, health-care, automobile, defense and Hollywood. There is also a growing consumermarket for home based 3D printers.

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Figure 1.1: InMoov, a full-size humanoid robot made from 3D-printed parts,designed and built by Gael Langevin of Factices Ateliers in France

1.1 The Rise of 3D Printing

Figure 1.2: Charles W. Hull

The concept of 3D printing re-ally began to be taken seriouslyin the 1980s. The man most of-ten credited with inventing the lan-guage of modern 3D printer isCharles W. Hull, who used theterm stereolithographydefined asa system for generating three-dimensional objects by creatinga cross-sectional pattern of theobject to be formedin a 1984patent.

Manufacturing can be differenti-ated into two types:

Additive manufacturing refers to

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technologies that create ob-jects through sequential layer-ing.

Subtractive manufacturing refersto the technologies that create objects through the removal of materialby methods such as cutting and drilling.

Figure 1.3: 3D printed Shoes

The 3D printing technology isused for both prototyping and dis-tributed manufacturing with appli-cations in architecture, engineering,construction (AEC), industrial de-sign, automotive, aerospace, mil-itary, engineering, civil engineer-ing, dental and medical industries,biotech (human tissue replacement),fashion, footwear, jewelry, eyewear,education, geographic informationsystems, food, and many other

fields. It has been speculated that 3D printing may become a mass mar-ket item because open source 3D printing can easily offset their capitalcosts by enabling consumers to avoid costs associated with purchasing com-mon household objects.

1.2 General Principles

1.2.1 Modeling

Figure 1.4: 3D Render of the popularinternet meme: Grumpy Cat

Additive manufacturing takes vir-tual blueprints from computer aideddesign (CAD) or animation model-ing software and slices them intodigital cross-sections for the machineto successively use as a guideline forprinting. Depending on the machineused, material or a binding materialis deposited on the build bed or plat-form until material/binder layeringis complete and the final 3D model

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has been printed.A standard data interface between CAD software and the machines is theSTL file format. An STL file approximates the shape of a part or assemblyusing triangular facets. Smaller facets produce a higher quality surface. PLYis a scanner generated input file format, and VRML (or WRL) files are oftenused as input for 3D printing technologies that are able to print in full color.

There are many Softwares you can use for modelling your 3D models thatare 100% free;

- Google SketchUp

- 3DCrafter

- 3Dtin

- Anim8or

- Art of Illusion

- Blender

- BRL-CAD

- Creo Elements/Direct

- DrawPlus Starter Edition

- FreeCAD

- GLC Player

- LeoCAD

- K-3D

- Tinkercad

- Wings 3D

1.2.2 Printing

To perform a print, the machine reads the design from an .stl file and laysdown successive layers of liquid, powder, paper or sheet material to buildthe model from a series of cross sections. These layers, which correspond tothe virtual cross sections from the CAD model, are joined or automaticallyfused to create the final shape. The primary advantage of this technique isits ability to create almost any shape or geometric feature.

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Figure 1.5: An example of a home 3D Printer, the Makerbot Replicator 2

1.2.3 Finishing

Figure 1.6: The completely printedGrumpy Cat

Though the printer-produced res-olution is sufficient for many ap-plications, printing a slightly over-sized version of the desired ob-ject in standard resolution andthen removing material with ahigher-resolution subtractive pro-cess can achieve greater preci-sion.

Some additive manufacturingtechniques are capable of using mul-tiple materials in the course of con-structing parts. Some are able toprint in multiple colors and colorcombinations simultaneously. Some

also utilize supports when building. Supports are removable or dissolvableupon completion of the print, and are used to support overhanging featuresduring construction.

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Chapter 2

3D Printing Techniques andMaterials

2.1 3D Printing Techniques

Stereolithography(SLA)

The first commercially available 3D printer (not called a 3D printer backthen) used the stereolithography (SLA) method. This was invented in 1986by Charles Hull, who also at the time founded the company, 3D Systems. ASLA 3D printer works by concentrating a beam of ultraviolet light focusedonto the surface of a vat filled with liquid photocurable resin. The UV laserbeam draws out the 3D model one thin layer at a time, hardening that slice ofthe eventual 3D model as the light hits the resin. Slice after slice is created,with each one bonded to the other, and next thing you know you have afull, extremely high-resolution three dimensional model lifted out of the vat.Unused resin is reusable for the next job.

Fused Deposition Modeling (FDM)

Also invented in the late 1980s, by Scott Crump, was Fused Deposition Mod-eling (FDM) technology. With patent in hand, he and his wife foundedStratasys in 1988. With FDM, the object is produced by extruding a streamof melted thermoplastic material to form layers. Each layer stacks on top ofand fuses with the previous layer as the material hardens almost immediatelyafter leaving the extrusion nozzle. It is one of the less expensive 3D printingmethods. Most FDM printers print with ABS plastic (think Lego), as wellas PLA (Polylactic acid), a biodegradable polymer, which is produced fromorganic material.

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Selective Laser Sintering (SLS)

The 1980s were big for inventing 3D printing technologies. Not only were SLAand FDM invented and patented then, but so was Selective Laser Sintering(SLS), by Carl Deckard and colleagues at the University of Texas in Austin.SLS works similarly to SLA, but instead of liquid photopolymer in a vat,youll find powdered materials, such as polystyrene, ceramics, glass, nylon,and metals including steel, titanium, aluminum, and silver. When the laserhits the powder, the powder is fused at that point (sintered). All unsinteredpowder remains as is, and becomes a support structure for the object. Thelack of necessity for any support structure with SLS is an advantage overFDM/FFF and SLA theres none to remove after the model is complete, andno extra waste was created. All unused powder can be used for the nextprinting.

PolyJet photopolymer

Objet (acquired by Stratasys) developed this technology: much like a tradi-tional inkjet printer deposits ink, a photopolymer liquid is precisely jettedout and then hardened with a UV light. The layers are stacked successively.The technology allows for various materials and colors to be incorporatedinto single prints, and at high resolutions.

Syringe Extrusion

Almost any material that has a creamy viscosity can be used in 3D printersequipped with syringe extruders. This includes materials like clay, cement,silicone, and Play-Doh. Certain foods like chocolate, frosting, and cheesecan also be printed with these systems. The syringe may or may not need tobe heated, depending on the material; chocolate may need to be kept warmwhile silicone can be kept at room temperature.

Other Methods

There are other variants of these technologies. For example there is SelectiveLaser Melting (SLM), which is like SLS but it fully melts the powder ratherthan just fusing the powder granules at a lower temperature. This is similarto Electron Beam Melting (EBM) which uses an electron beam instead of aUV laser. And then there is a completely different technology called Lami-nated Object Manufacturing (LOM), where layers of adhesive-coated paper,plastic, or metal laminates are successively glued together and cut to shapewith a knife or laser cutter.

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Figure 2.1: Sapeways company logo

2.2 3D Printing Materials

Many different materials can be used for 3D printing, such as ABS plastic,PLA, polyamide (nylon), glass filled polyamide, stereolithography materials(epoxy resins), silver, titanium, steel, wax, photopolymers and polycarbon-ate.

Shapeways is a Dutch founded, New York based 3D printing marketplaceand service, startup company. Users upload design files, and Shapewaysprints the objects for them or others. Users can have objects printed from avariety of materials, including food-safe ceramics.

They offer to print your model in the following materials:

Strong and Flexible Plastic

Great starter material-easy design rules, feels a bit rough, but available inpolished finish.

Figure 2.2: Strong & Flexible Plastic

Alumide

Brittle Nylon Plastic thats filled with Aluminum dust.

Figure 2.3: Alumide

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Detail Plastic

Acrylic based polymer that can print fine details. Smooth and slightly shiny.

Figure 2.4: Detail Plastic

Frosted Detail Plastic

UV-cured acrylic plastic that prints fine details and walls. Smooth andtranslucent.

Figure 2.5: Frosted Detail Plastic

Steel

Great for jewelry and durable pieces. The shiny surface is slightly pitted &rough.

Figure 2.6: Steel

Sterling Steel

Real Sterling Silver is available in 3 levels of polish from rough Raw Silverto pristine Premium Silver.

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Figure 2.7: Sterling Silver

Other Materials

Their other materials include Brass, Bronze, Elasto Plastic, Full Colour Sand-stone and ceramics.

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Chapter 3

The Future of 3D Printing

Figure 3.1: The RepRap 3D Printer

Several projects and companies aremaking efforts to develop afford-able 3D printers for home desk-top use. Much of this work hasbeen driven by and targeted atDIY/enthusiast/early adopter com-munities, with additional ties tothe academic and hacker communi-ties.

RepRap is one of the longestrunning projects in the desktop cat-egory. The RepRap project aims toproduce a free and open source

software (FOSS) 3D printer, whose full specifications are released underthe GNU General Public License, and which is capable of replicating itself byprinting many of its own (plastic) parts to create more machines. Researchis under way to enable the device to print circuit boards and metal parts.

Because of the FOSS aims of RepRap, many related projects have usedtheir design for inspiration, creating an ecosystem of related or derivative3D printers, most of which are also open source designs. The availabilityof these open source designs means that variants of 3D printers are easy toinvent. The quality and complexity of printer designs, however, as well asthe quality of kit or finished products, varies greatly from project to project.

This rapid development of open source 3D printers is gaining interest inmany spheres as it enables hyper-customization and the use of public do-

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main designs to fabricate open source appropriate technology through con-duits such as Thingiverse and Cubify. This technology can also assistinitiatives in sustainable development since technologies are easily and eco-nomically made from resources available to local communities.

Figure 3.2: The MakerBot CupcakeCNC.

The cost of 3D printers has de-creased dramatically since about2010, with machines that used tocost $20,000 costing less than $1,000.For instance, as of 2013, several com-panies and individuals are sellingparts to build various RepRap de-signs, with prices starting at about400 / US$500. The open sourceFab@Home project has developedprinters for general use with any-thing that can be squirted througha nozzle, from chocolate to sili-cone sealant and chemical reactants.Printers following the projects de-signs have been available from sup-pliers in kits or in pre-assembledform since 2012 at prices in theUS$2000 range. The Kickstarter funded Peachy Printer is designed tocost $100 and several other new 3D printers are aimed at the small, inexpen-sive market including the mUVe3D and Lumifold.

As the costs of 3D printers have come down they are becoming moreappealing financially to use for self-manufacturing of personal products. Inaddition, 3D printing products at home may reduce the environmental im-pacts of manufacturing by reducing material use and distribution impacts.

3.1 3Doodler

The 3Doodler is a 3D printing pen developed by Peter Dilworth andMaxwell Bogue of WobbleWorks LLC. 3Doodler began funding in Febru-ary 2013 on the crowd funding platform Kickstarter.

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Figure 3.3: 3Doodler Pen

It utilizes plastic thread made of either acrylonitrile butadiene styrene(ABS) or polylactic acid (PLA) that is melted and then cooledthrough a patented process while moving through the pen, which can thenbe used to make 3D objects by hand. The 3Doodler has been described asa glue gun for 3D printing because of how the plastic is extruded from thetip, with one foot of the plastic thread equaling about 11 feet of moldablematerial.

Figure 3.4: A 3Doodler Pen being used

3.2 3D Printed Organs

The dream of one day completely doing away with frustratingly long trans-plant lists in favor of made to order, 3D-printed organs is closer to becominga reality. Scientists at Organovo in San Diego have, for the very first time,

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been able to 3D print tiny replicas of human livers.

Figure 3.5: A scientist printing out the liver

At just half a millimeter deep and four millimeters across, the mini liverscan perform most of the same functions as the larger version hanging out overyour gallbladder. Which means that these presumably adorable bile-makersstand to serve a variety of purposes, the most immediate of which would beusing them to observe how our livers react to certain drugs and diseases.

From here, Organovo plans to move on to the normal-sized organs thatcould be transplanted into real, live human bodies. Of course, theyd firsthave to solve the problem of how to print larger branches of blood vesselnetworks capable of nourishing an entire organ. But if these itty bitty liversare any indication, the real deal is well on its way.

3.3 3D Printed Food

In a fantastic development, the application of additive manufacturing tech-nologies that other 3D printing enthusiasts and myself have long been pro-moting, NASA has recently awarded a $125,000 grant to further explore anddevelop the application of 3D printing food for astronauts. Initially aimedat efficient food storage for long-haul space flights, the creator of this projectAnjan Contractor, a Senior Mechanical Engineer at Systems and MaterialsResearch Corporation (SMRC) in Austin, Texas, USA hopes this technology

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could ultimately help the continually exponentially increasing population onEarth.

Figure 3.6: The schematic for a hypothetical 3D food printer.

In the plan, a NASA-modified RepRap printer will be fitted with sev-eral culinary building blocks, from oil to protein powder, then mixed anddeposited. As 3D printing typically utilises a layer on layer based methodol-ogy, layer-based foods like pizza are first on the menu.

Accordingly, Contractor envisions: customized, nutritionally-appropriatemeals synthesized one layer at a time, from cartridges of powder and oils.So for the pizza, the 3D printer would mix the appropriate ingredients todeposit a layer of dough, which would be cooked prior to laying down thenext of tomato sauce (from a mixture of powder, water and oil. Additionallayers of protein can then be added.

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Bibliography

Wikipeda, en.wikipedia.org/wiki/3D_printing

Shapeways, www.shapeways.com

3D Printing Industry, 3dprintingindustry.com

Gizmodo www.gizmodo.com

Wired www.wired.com

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IntroductionThe Rise of 3D PrintingGeneral PrinciplesModelingPrintingFinishing

3D Printing Techniques and Materials3D Printing Techniques3D Printing Materials

The Future of 3D Printing3Doodler3D Printed Organs3D Printed Food