3d Printer.docx

P.S.N.A College of Engineering and Techology Dindigul - 624622

3D PRINTER Submitted By: M. SITHIMANIKANDAN P.SOORYA KUMAR SECOND YEAR STUDENTS, DEPARTMENT OF MECHANICAL ENGINEERING. [email protected] [email protected]

Contents: •

Introduction

•

History of 3d printer?

•

What is 3D Printing?

•

How does 3d printing works?

•

From 3d model to 3d modeling?

•

Learn how to 3d print?

•

Different types of 3d printer?

•

Principles & procedure of 3d printer?

•

Application of 3d printer?

P.S.N.A College of Engineering and Techology Dindigul - 624622

•

Advantages and limitation of 3d printer?

•

Future of technology

Introduction 3D printing is a technology which makes it possible to build real objects from virtual 3D objects. This is done by “cutting” the virtual object in 2D slices and printing the real object slice by slice. Slices are printed on top of each other and since each slice has a given thickness, e.g. 0.15 mm, the real object gains volume every time a slice is added.

History In the history of manufacturing, subtractive methods have often come first. The province of machining (generating exact shapes with high precision) was generally a subtractive affair, from filing and turning through milling and grinding. Additive manufacturing’s earliest applications have been on the tool room end of the manufacturing spectrum. For example, rapid prototyping was one of the earliest additive variants and its mission was to reduce the lead time and cost of developing prototypes of new parts and devices, which was earlier only done with subtractive tool room methods (typically slowly and expensively). However, as the years go by and technology continually advances, additive methods are moving ever further into the production end of manufacturing. Parts that formerly were the sole province of subtractive methods can now in some cases be made more profitably via additive ones. However, the real integration of the newer additive technologies into commercial production is essentially a matter of complementing subtractive methods rather than displacing them entirely. Predictions for the future of commercial manufacturing, starting from today’s already- begun infancy period, are that manufacturing firms will need to be flexible, ever-improving users of all available technologies in order to remain competitive.

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What is 3D printing? 3D printing or additive manufacturing is a process of making three dimensional solid objects from a digital file. The creation of a 3D printed object is achieved using additive processes. In an additive process an object is created by laying down successive layers of material until the object is created. Each of these layers can be seen as a thinly sliced horizontal cross-section of the eventual object. How does 3D printing work? It all starts with making a virtual design of the object you want to create. This virtual design is for instance a CAD (Computer Aided Design) file. This CAD file is created using a 3D modeling application or with a 3D scanner (to copy an existing object). A 3D scanner can make a 3D digital copy of an object.

3D scanners use different technologies to generate a 3D model. Examples are: time-offlight, structured / modulated light, volumetric scanning and many more. Recently, companies like Microsoft and Google enabled their hardware to perform 3D scanning, for example Microsoft’s Kinect. In the near future digitising real objects into 3D models will become as easy as taking a picture. Future versions of smartphones will probably

have

integrated

3D

scanners.

Currently, prices of 3D scanners range from expensive professional industrial devices to anyone

can

make

at

home.

3D modeling software also comes in many forms. There’s industrial grade software that costs thousands a year per license, but also free open source software, like r, for instance.

P.S.N.A College of Engineering and Techology Dindigul - 624622

From 3D model to 3D printer You will have to prepare a 3D model before it is ready to be 3D printed. This is what they call slicing. Slicing is dividing a 3D model into hundreds or thousands of horizontal

layers

and

needs

to

be

done

with

software.

Sometimes a 3D model can be sliced from within a 3D modeling software application. It is also possible that you are forced to use a certain slicing tool for a certain 3D printer. When the 3D model is sliced, you are ready to feed it to your 3D printer. This can be done via USB, SD or wifi. It really depends on what brand and type 3D Printer you have. When a file is uploaded in a 3D printer, the object is ready to be 3D printed layer by layer. The 3D printer reads every slice (2D image) and creates a three dimensional object. How Does 3D Printer works? Getting started with 3D printing means asking yourself what you would like to learn first. Are you interested in the hardware, or do you want to focus on creating objects? We’ve created a 3D printers for beginner’s buyer’s guide to help you decide if you should choose

a

pre-assembled

3D

Printer

or

a

3D

printer

kit.

In case you have a tight budget and you want to start your journey into learning 3D printing, cheap 3D printer kits can be a great starting point. If you are interested in going this route, please read our article about cheap 3D printer kits. This article explains what to look for when you’re comparing DIY kits Applications of 3D printing Applications include rapid prototyping, architectural scale models & maquettes, healthcare (3D printed prosthetics and 3D printing with human tissue) and entertainment (e.g. movie props).

P.S.N.A College of Engineering and Techology Dindigul - 624622

Other examples of 3D printing would include reconstructing fossils in paleontology, replicating ancient artifacts in archaeology, reconstructing bones and body parts in forensic pathology and reconstructing heavily damaged evidence acquired from crime scene investigations.

1. Vat Photopolymerisation 2. Stereolithography (SLA) 3. Digital Light Processing (DLP) 4. Continuous Liquid Interface Production (CLIP) 5. Material Jetting 6. Binder Jetting 7. Material Extrusion 8. Fused Deposition Modeling (FDM) 9. Fused Filament Fabrication (FFF) 10. Powder Bed Fusion 11. Selective laser sintering (SLS) 12. Sheet Lamination 13. Directed Energy Deposition Below you’ll find a short explanation of all of seven processes for 3D printing:

Vat Photopolymerisation A 3D printer based on the Vat Photopolymerisation method has a container filled with photopolymer resin which is then hardened with a UV light source.

P.S.N.A College of Engineering and Techology Dindigul - 624622

Vat photopolymerisation schematics. Image source: lboro.ac.uk

Stereolithography (SLA) The most commonly used technology in this processes is Stereolithography (SLA). This technology employs a vat of liquid ultraviolet curable photopolymer resin and an ultraviolet laser to build the object’s layers one at a time. For each layer, the laser beam traces a cross-section of the part pattern on the surface of the liquid resin. Exposure to the ultraviolet laser light cures and solidifies the pattern traced on the resin and joins it to the layer below. After the pattern has been traced, the SLA’s elevator platform descends by a distance equal to the thickness of a single layer, typically 0.05 mm to 0.15 mm (0.002″ to 0.006″). Then, a resin-filled blade sweeps across the cross section of the part, re-coating it with fresh material. On this new liquid surface, the subsequent layer pattern is traced, joining the previous layer. The complete three dimensional object is formed by this

P.S.N.A College of Engineering and Techology Dindigul - 624622

project. Stereolithography requires the use of supporting structures which serve to attach the part to the elevator platform and to hold the object because it floats in the basin filled with liquid resin. These are removed manually after the object is finished. This technique was invented in 1986 by Charles Hull, who also at the time founded the company, 3D Systems.

Digital Light Processing (DLP) DLP or Digital Light Processing refers to a method of printing that makes use of light and photosensitive polymers. While it is very similar to stereolithography, the key difference is the light-source. DLP utilizes traditional light-sources like arc lamps. In most forms of DLP, each layer of the desired structure is projected onto a vat of liquid resin that is then solidified layer by layer as the build plate moves up or down. As the process does each layer successively, it is quicker than most forms of 3D printing. The Envision Tec Ultra, MiiCraft High Resolution 3D printer, and Luna vast XG2 are examples of DLP printers. Companies that specialize in DLP technology include ONO and Carbon (who invented a subtype of DLP called CLIP).

Continuous Liquid Interface Production (CLIP) Other technologies using Vat Photopolymerisation are the new ultrafast Continuous Liquid

Interface

Production

or CLIP and

Imaging and Solid Ground Curing.

Material Jetting

marginally

used

older Film

Transfer

P.S.N.A College of Engineering and Techology Dindigul - 624622

In this process, material is applied in droplets through a small diameter nozzle, similar to the way a common inkjet paper printer works, but it is applied layer-by-layer to a build platform making a 3D object and then hardened by UV light.

Binder Jetting With binder jetting two materials are used: powder base material and a liquid binder. In the build chamber, powder is spread in equal layers and binder is applied through jet nozzles that “glue” the powder particles in the shape of a programmed 3D

P.S.N.A College of Engineering and Techology Dindigul - 624622

object. The finished object is “glued together” by binder remains in the container with the powder base material. After the print is finished, the remaining powder is cleaned off and used for 3D printing the next object. This technology was first developed at the Massachusetts Institute of Technology in 1993 and in 1995 Z Corporation obtained an exclusive license.

The following video shows a high-end binder jetting based 3D printer, the ExOne M-Flex. This 3D printer uses metal powder and curing after the binding material is applied.

P.S.N.A College of Engineering and Techology Dindigul - 624622

Material Extrusion The most commonly used technology in this process is Fused Deposition Modeling (FDM)

Fused Deposition Modeling (FDM)

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The FDM technology works using a plastic filament or metal wire which is unwound from a coil and supplying material to an extrusion nozzle which can turn the flow on and off. The nozzle is heated to melt the material and can be moved in both horizontal and vertical directions by a numerically controlled mechanism, directly controlled by a computer-aided manufacturing (CAM) software package. The object is produced by extruding melted material to form layers as the material hardens immediately after extrusion from the nozzle. This technology is most widely used with two plastic filament material types: ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic acid). Though

P.S.N.A College of Engineering and Techology Dindigul - 624622

many other materials are available ranging in properties from wood fill to flexible and even conductive materials. FDM was invented by Scott Crump in the late 80’s. After patenting this technology he started the company in 1988. The software that comes with this technology automatically generates support structures if required. The machine dispenses two materials, one for the model and one for a disposable support structure. The term fused deposition modeling and its abbreviation to FDM are trademarked by Stratasys Inc.

Fused Filament Fabrication (FFF) The exactly equivalent term, Fused Filament Fabrication (FFF), was coined by the members of the RepRap project to give a phrase that would be legally unconstrained in its use.

Powder Bed Fusion The most commonly used technology in this processes is Selective Laser Sintering (SLS).

Selective Laser Sintering (SLS) SLS uses a high power laser to fuse small particles of plastic, metal, ceramic or glass powders into a mass that has the desired three dimensional shape. The laser selectively fuses the powdered material by scanning the cross-sections (or layers) generated by the 3D modeling program on the surface of a powder bed. After each crosssection is scanned, the powder bed is lowered by one layer thickness. Then a new layer of material is applied on top and the process is repeated until the object is completed.

P.S.N.A College of Engineering and Techology Dindigul - 624622

All untouched powder remains as it is and becomes a support structure for the object. Therefore there is no need for any support structure which is an advantage over SLS and SLA. All unused powder can be used for the next print. SLS was developed and patented by Dr. Carl Deckard at the University of Texas in the mid-1980s, under sponsorship of DARPA.

Sheet Lamination Sheet lamination involves material in sheets which is bound together with external force. Sheets can be metal, paper or a form of polymer. Metal sheets are welded together by ultrasonic welding in layers and then CNC milled into a proper shape. Paper sheets

P.S.N.A College of Engineering and Techology Dindigul - 624622

can be used also, but they are glued by adhesive glue and cut in shape by precise blades. A leading company in this field is Technologies.

Principles & procedure of 3d printer Three dimensional printing allows you to turn a digital 3D model into a tangible object. This article will help the computer savvy to build and print a cylinder model using CAD software. This is for those who have CAD experience but not necessarily those with printing experience. The basics of this tutorial can be applied to much more complex designs. Determine whether it's a Makerbot Davinci or Replicator. Then you'll need to know whether it's a layer-on or a cut away printer. 

Use a tool such as Tinkercad, Google Sketchup, or Blender. Put it through the file preparation software for your specific device. (You can find this on the manufacturer's website). Advantages: 

Customization – A major advantage in 3d printing. With just a raw material, a blueprint and a 3d printer, one can print any design no matter how complex it might be.



Constant Prototyping and Increased Productivity – It enables quick production with a high number of prototypes or a small-scale version of the real object in less time than using conventional methods. This helps designers to improve their prototypes, for any design flaws that may affect the quality of the product.

P.S.N.A College of Engineering and Techology Dindigul - 624622



Affordability – The initial cost for setting up a 3d printing facility is definitely high; however, it is much cheaper compared to labor costs and manufacturing costs while using the conventional way. Adding to it, is the fact that the cost of producing or manufacturing products using 3d printing technology is equal for small-scale and mass manufacturing.



Storage – Traditional manufacturing produces additional products that you probably know you will eventually need thus storage problems arise. However, 3d printing technology, products can be “printed” when needed thus excess products are eliminated and no storage cost is required.



Employment Opportunities – The widespread use of 3d printing technology will definitely increase the demand for engineers who are needed to design and build these printers. Technicians who are skilled at troubleshooting and maintenance and Designers to design blueprints for products and more jobs will be created.



Health Care – With the advancement of technology, a customizable human body parts and organs can now be manufactured this technology is termed as Bioprinting. Although right now this is still experimental, the potential is huge. This breakthrough will not only address the shortage of organ donors, but also organ rejection since the organs that are built will consist of the patient’s unique characters and DNA.

Disadvantages 

Decrease in Manufacturing Jobs – The decrease in manufacturing jobs will greatly affect the economy of countries that rely on a large number of low skill jobs.

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

Limited Size – The size of objects created with 3d printers is currently limited however, in the near future; large items such as architectural structures can be created using 3d printing.



Limited Raw Materials – Traditional manufacturing of products has an enormous range of raw materials that can be used. Presently 3d printers can work up to approximately 100 different raw materials and creating products that uses more raw materials are still under development.



Violation of Copyrights – The biggest disadvantage of 3d printing is Counterfeiting. Anyone who gets a hold of a blueprint will be able to counterfeit products easily. It will become more common and tracing the source of the counterfeited items will be nearly impossible. Many copyright holders will have a hard time protecting their rights and businesses producing unique products will suffer.



Production of Dangerous Items – With 3d printers, plastic knives, guns and any other hazardous objects can be created. It makes easier for terrorists and criminals bring a weapon without being detected.

Future It is predicted by some additive manufacturing advocates that this technological development will change the nature of commerce, because end users will be able to do much of their own manufacturing rather than engaging in trade to buy products from other people and corporations.