Introduction to 3D Printing

3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. It is also known as rapid prototyping, is a mechanized method whereby 3D objects are quickly made on a reasonably sized machine connected to a computer containing blueprints for the object. The 3D printing concept of custom manufacturing is exciting to nearly everyone. This revolutionary method for creating 3D models with the use of inkjet technology saves time and cost by eliminating the need to design; print and glue together separate model parts. Now, you can create a complete model in a single process using 3D printing. The basic principles include materials cartridges, flexibility of output, and translation of code into a visible pattern.

Typical 3D Printer

3D Printers are machines that produce physical 3D models from digital data by printing layer by layer. It can make physical models of objects either designed with a CAD program or scanned with a 3D Scanner. It is used in a variety of industries including jewelry, footwear, industrial design, architecture, engineering and construction, automotive, aerospace, dental and medical industries, education and consumer products.

The technology for printing physical 3D objects from digital data was first developed by Charles Hull in 1984. He named the technique as Stereo lithography and obtained a patent for the technique in 1986. While Stereo lithography systems had become popular by the end of 1980s, other similar technologies such as Fused Deposition Modeling (FDM) and Selective Laser Sintering (SLS) were introduced. In 1993, Massachusetts Institute of Technology (MIT) patented another technology, named "3 Dimensional Printing techniques", which is similar to the inkjet technology used in 2D Printers. In 1996, three major products, "Genisys" from Stratasys, "Actua 2100" from 3D Systems and "Z402" from Z Corporation were introduced. In 2005, Z Corp. launched a breakthrough product, named Spectrum Z510, which was the first high definition color 3D Printer in the market. Another breakthrough in 3D Printing occurred in 2006 with the initiation of an open source project, named Reprap, which was aimed at developing a self-replicating 3D printer.

Current 3D Printing Technologies

Stereo lithography - Stereo lithographic 3D printers (known as SLAs or stereo lithography apparatus) position a perforated platform just below the surface of a vat of liquid photo curable polymer. A UV laser beam then traces the first slice of an object on the surface of this liquid, causing a very thin layer of photopolymer to harden. The perforated platform is then lowered

very slightly and another slice is traced out and hardened by the laser. Another slice is then created, and then another, until a complete object has been printed and can be removed from the vat of photopolymer, drained of excess liquid, and cured. Fused deposition modeling - Here a hot thermoplastic is extruded from a temperature-controlled print head to produce fairly robust objects to a high degree of accuracy. Selective laser sintering (SLS) - This builds objects by using a laser to selectively fuse together successive layers of a cocktail of powdered wax, ceramic, metal, nylon or one of a range of other materials.

Multi-jet modeling (MJM) - This again builds up objects from successive layers of powder, with an inkjet-like print head used to spray on a binder solution that glues only the required granules together. The V-Flash printer, manufactured by Canon, is low-cost 3D printer. It’s known to build layers with a light-curable film. Unlike other printers, the VFlash builds its parts from the top down. Desktop Factory is a startup launched by the Idea lab incubator in Pasadena, California.

Fab@home, an experimental project based at Cornell University, uses a syringe to deposit material in a manner similar to FDM. The inexpensive syringe makes it easy to experiment with different materials from glues to cake frosting.

Inkjet 3D printingIt creates the model one layer at a time by spreading a layer of powder (plaster, or resins) and inkjet printing binder in the cross-section of the part. It is the most widely used 3-D Printing technology these days and the reasons beyond that are stated below.This technology is the only one that

Allows for the printing of full color prototypes. Unlike stereo lithography, inkjet 3D printing is optimized for speed, low cost, and ease-

of-use. No toxic chemicals like those used in stereo lithography are required. Minimal post printing finish work is needed; one needs only to use the printer itself to

blow off surrounding powder after the printing process. Allows overhangs and excess powder can be easily removed with an air blower.

MANUFACTURING A MODEL WITH THE 3D PRINTER

The model to be manufactured is built up a layer at a time. A layer of powder is automatically deposited in the model tray. The print head then applies resin in the shape of the model. The layer dries solid almost immediately. The model tray then moves down the distance of a layer and another layer of power is deposited in position, in the model tray. The print head again

applies resin in the shape of the model, binding it to the first layer. This sequence occurs one layer at a time until the model is complete.

ALGORITHM

The algorithm used in the Inkjet 3-D Printing is depicted in the figure mentioned below.

FIGURE 4.1.1

WORK FLOW

The workflow can be easily understood with the help of the flowchart given below.A 3-D prototype of a desired object is created in three basic steps and these steps are:

Pre-Process 3-D Printing Post-Process

FIGURE 5.1

PROCESS

6.1 CAD Preparation (Pre-Process):

Computer-aided design (CAD), also known as computer-aided design and drafting

(CADD), is used to prepare a 3-D or 2-D model of the desired object. Modern CAD

packages can also frequently allow rotations in three dimensions, allowing viewing of a

designed object from any desired angle.

Most 3D printers require a special file (typically .stl format) to print. Additionally, we

need to modify the design to make up for limitations of the printer and build material.

FIGURE 6.1.1

3D Printing:

The 3D printer runs automatically, depositing materials at layers ~.003″ thick. This is

roughly the thickness of a human hair or sheet of paper. The time it takes to print a given

object depends primarily on the height of the design, but most designs take a minimum of

several hours. The average cost for printing a full color prototype is somewhere between

50 - 100 $.

FIGURE 6.2.1

Cleaning 3D Printouts (Post-Process):

Every 3D printer uses some sort of material to support parts of the design that have an

overhang. Some printers use a loose powder which can be blown off and reused in future

models.

FIGURE 6.3.1

Here you have the “Han Solo in Carbonite” stage…

Powder Removal:

This is the sculpture with most of the support dust removed and it is then dipped in

special glue that makes them stronger and more colorful.

FIGURE 6.3.1.1

Heating

The models are heated to set the glue. It is funny to see the oven in this picture is a

standard consumer grade.

FIGURE 6.3.2.1

Finishing Touches

The output of all existing 3D printers is rough. The textures vary from pronounced “wood grain” to merely “sandy”, With a little elbow grease you can get stunning results.

FIGURE 6.3.3.1

Benefits of 3D Printing

The most successful companies have adopted 3D printing as a critical part of the iterative design process to:

Increase Innovation

Print prototypes in hours, obtain feedback, refine designs and repeat the cycle until designs are perfect.

Improve Communication

Hold a full color, realistic 3D model in your hands to impart infinitely more information than a computer image.

Create physical 3D models quickly, easily and affordably for a wide variety of applications.

Speed Time to Market

Compress design cycles by 3D printing multiple prototypes on demand, right in your office.

Reduce Development Costs

Cut traditional prototyping and tooling costs.

Identify design errors earlier.

Reduce travel to production facilities.

Win Business

Bring realistic 3D models to prospective accounts, sponsors and focus groups

Applications

Design Prototypes:

3-Dimensional Printing concept model, functional prototypes and presentation models for evaluating and refining design, including Finite Element Analysis (FEA) results and packaging.

FIGURE 8.1.1

Now, here we have created a dummy of a Nokia mobile phone for further study and demonstration:

Size: 3.5 x 2 x 0.7 inches (9 x 5 x 2 cm) Printing Time: 0.5 hours

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Education:

Engage students by bringing digital concepts into the real world, turning their ideas into real-life 3D color models that they can actually hold in their hands.

Here an electronic device circuit has come to life with the help of a 3-D Printer:

Size: 8 x 5 x 2.5 inches (20 x 13 x 6 cm) Printing Time: 3 hours

FIGURE 8.2.1

(15)8.3 Healthcare:

Rapidly produce 3D models to reduce operating time, enhance patient and physician communications, and improve patient outcomes.

A 3-D Prototype of the horizontal crossection of a human skull has been prepared to allow its better study:

Size: 9.8 x 7.9 x 3.9 inchesFIGURE

8.3.1 (25 x 20 x 10 cm) Printing Time: 5.5 hours

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1. 3D Printing Success Story

Camera mounts for the M1 tank and Bradley fighting vehicle were built and tested directly from digital files using the Dimension 3D Printer.

FIGURE 9.1

(17) A 3D printer proved to be a

valuable assetand played a key role in developing concepts for the AMP Research Alloy Fuel Door for General Motors' Hummer H2 sport utility vehicle.

Conclusion

Nothing communicates ideas faster than a three-dimensional part or model. With a 3D printer you can bring CAD files and design ideas to life – right from your desktop. Test form, fit and function – and as many design variations as you like – with functional parts. In an age in which the news, books, music, video and even our communities are all the subjects of digital dematerialization, the development and application of 3D printing reminds us that human beings have both a physical and a psychological need to keep at least one foot in the real world. 3D printing has a bright future, not least in rapid prototyping (where its impact is already highly significant), but also in medicine the arts, and outer space. Desktop 3D printers for the home are already a reality if you are prepared to pay for one and/or build one yourself. 3D printers capable of outputting in color and multiple materials also exist and will continue to improve to a point where functional products will be able to be output. As devices that will provide a solid bridge between cyberspace and the physical world, and as an important manifestation of the Second Digital Revolution, 3D printing is therefore likely to play some part in all of our futures.