Prototype e-Book

Prototyping Basics Vol. 2

http://www.PrototypeZone.com

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Table of Contents DISCLAIMER ..................................................................................... 2

History of Rapid Prototyping ............................................................ 5

Inventions and Prototypes ............................................................... 7

Injection Molding Prototyping .......................................................... 9

3D printers ..................................................................................... 11

3D printing technology ................................................................... 13

3D scanning and Prototyping .......................................................... 15

Additive fabrication ........................................................................ 17

Advantages of rapid prototyping .................................................... 19

Casting Prototype ........................................................................... 21

Designing and Prototyping ............................................................. 23

Disadvantages of Rapid Prototyping ............................................... 25

DIY Rapid Prototyping - Home Made 3D Printer ............................. 28

Electron Beam Melting .................................................................... 30

Fused Deposition Modeling ............................................................. 32

Laminated Object Manufacturing .................................................... 34

Prototyping vs. rapid prototyping ................................................... 36

Rapid manufacturing ...................................................................... 39

Rapid Prototyping ........................................................................... 41

Rapid Prototyping Overseas ........................................................... 43

Rapid prototyping services ............................................................. 45

Rapid Prototyping Technologies ..................................................... 47

Reverse engineering ....................................................................... 50



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Selective laser sintering ................................................................. 53

Stereolithography ........................................................................... 55

Virtual Prototyping ......................................................................... 57



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History of Rapid Prototyping Rapid prototyping is applied for the construction of physical objects by

making use of solid freedom fabrications. Generative manufacturing or

Layered manufacturing are the alternative names for rapid prototyping. The

above terms are generally related with creation of objects of three-

dimensional views from the CAD files. The history of rapid prototyping can

be studied by understanding the changes in the prototyping methods.

Prototyping wax is the common material found in rapid prototyping systems.

Wax is suitable when designers and engineers require small quantities of

casting parts in the manufacturing process. Prototyping wax helps to

improve the efficiency of the initial prototype. Use of wax also facilitates the

prototype to work flexibly with metals and non-metals.

Low temperature furnaces and vacuum plasters can be produced when the

prototype wax is mixed with other materials. Layer after layer of material is

added for creation of the model and the method of cutting from the solid

block is not applied. With this type of arrangement, complex shapes are less

prone to errors. In simpler terms rapid prototyping can be termed as speedy

fabrication of the sample part for demonstrating, evaluation and testing

which makes the use of advanced manufacturing technologies for the

generation of quick three dimensional view designs.

The history of rapid prototyping is very interesting and dates back to several

years. Rapid prototyping has gone under several changes with the advent of

technology. Rapid prototyping is a very useful tool, which helps to curb the

costs and improve the designs. Different rapid prototyping processes are

used for different jobs. The implementation of the first technique was done



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in late 80's to make prototype parts and models. Today rapid prototyping is

used widely in applications and in manufacturing of quality parts of complex

designs and shapes. Ever since rapid prototyping has taken its roots in the

machine age, it has always followed the principal of WYSIWYG process (what

you see is what you get). Rapid prototyping is an important method that

helps to save time and money.

Rapid prototyping plays a vital role in the research and developmental

sector. Errors and flaws in the design can be easily plotted out with the help

of rapid prototyping. High quality goods and services can be provided to the

customers with implementation of rapid prototyping. Uncertainties of the

products are reduced to a considerable extent. Quick and effective decisions

can be taken by the management with the help of data obtained from rapid

prototyping. Thus, the history of rapid prototyping shows the fast

progression in this field.

Additional information regarding the structure, designs and techniques is

provided by the prototypes. A product has to go through different stages

before it is complete in order to maintain the quality of the product in all

stages prototyping plays a vital role. A better physical and visual

understanding of the product is provided to the manufacturing department

with rapid prototyping. It also helps the designers to keep the track of the

improvements in the designs. In any industry, statistical quality control plays

a key role in maintaining the quality of the product, rapid prototyping is the

vital element for the success of statistical quality control process. Rapid

prototyping helps to increase the flexibility and creativity in working climate.



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Inventions and Prototypes The process of creating a model of a system is known as Prototyping.

Prototypes can be used to help the system designers to develop an

information system which is quite easy to manipulate for the end users.

Prototyping can be called as a process which is a part of analysis phase of

the systems development life cycle. It is considered as an integral part of

the system design process and it helps to reduce the risk and cost of the

product. Generally, one or more prototypes are involved in the process of

iterative and incremental development. In this process, each prototype is

influenced by the previous designs and the problems in that design are

corrected.

When talking about inventions and prototypes, prototypes and design

plans can be very useful for invention of any new product. There are three

types of invention prototypes such as virtual prototypes, working prototypes

and physical prototypes. They can be used to assist the inventor in the

process of developing their invention for license or sale.

You can describe inventions and prototypes as the process of turning

your invention into a tangible product, which is known as 'reducing the

invention to practice'. A development of prototype is the key step in this

process. The prototype is an original model, which is later developed into a

specific pattern. A prototype may range from virtual drawings and non-

working models to 3D virtual designs showing functionality.



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Today, most manufacturers prefer inventions and prototypes. An

invention prototype can help the prospective company to understand the

invention and the reason for paying the royalties for it. The development of

physical, virtual or working prototype can help to create the design of the

invention before actual invention, production or development. It can help to

save the re-work and cost of the invention.

While using inventions and prototypes, prototypes go through different

stages. Prototyping the invention can help smooth out the design issues. The

first step involves establishing the basic design of your concept. You can

make the first crude prototypes from easy to find materials such as plastic

blocks or balsa wood. The basic concept design can be created by using files,

saws and sandpaper. It can give the basic idea about basic shape and size of

your invention. Once, final prototypical product is ready for consumer testing

through the development process, the manufacturing and marketing experts

opt for prototyping.

The invention moves towards perfection through each subsequent phase. It

is tested first by your business associates and then by the consumers. After

thorough testing, working production models are tested in the final stage. No

product is officially ready to launch in the market until the testing is done.

If your concept is to develop the machinery or emerging technology, it may

be difficult for you to prototype it. In such cases, computer generated

concept of art can be used along with CAD drawings. Invention prototypes

are essential for selling your product idea to the potential customers,

investors, suppliers and others.



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Injection Molding Prototyping In order to test various aspects of designs, ideas and features of a working

model, prototyping process is used. The projection risk and cost is reduced

with prototyping mechanism. With the prototyping process, the necessary

conceptual proof of the theory is provided which helps the organizations to

gather funds. An estimate of the product is obtained which is beneficial in

finalizing the systems. The process helps to encourage active participation

between the producers and the users of the products. The implementation of

injection molding prototyping proves to be cost effective and ensures higher

output to the users.

Prototyping helps to reduce the development costs and curb away the

unnecessary expenses. There is an overall boost in the quality and the

quantity of the product as it increases the system development speed. It

also minimizes and detects the errors or flaws in the design of the product.

The potential risks can be refined and suitable changes in development in

the delivery system can be made easily. Various aspects of the product can

be tested and positive feedback can be obtained from consumers. The

quality and quantity can be made stable according to the defined standards.

However, there lies a possibility of leaving systems unfinished. The systems

may be implemented before they are ready. As certain changes are required

constantly due to implementation of latest prototyping methods, the

structure may be adversely influenced. The method of prototyping is not

suitable in those areas where large applications are used.



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Injection Molding Prototyping is often used or implemented in those areas

where time is considered as a prime factor for production. This process was

invented in the year 1872. In this type, actual parts that are used for

engineering purpose are created from plastics. It provides the users with

rapid production techniques and powerful services. It makes use of a variety

of technologies that help to maintain high standard quality products in

negligible time. It has been a boon to the molding business and plastic

industries. Almost thirty two percent of the plastics are made with Injection

Molding Prototyping process. The machine used in the Injection Molding

Prototyping contains components like clamping system, hydraulic system,

mold system, injection system and the control system. For thermoplastics,

clamping tonnage and shot size play a vital role for identifying the

dimensions of the injection.

The injection machine is classified in three-sub categories tight-tolerance

machine, high-speed thin wall machines and general-purpose tool. All these

three types play a vital role in the industries. Injection Molding Prototyping

process has helped nearly all the industries to produce cheap and durable

goods to the customers. With the implementation of these techniques,

countries have become self sufficient in the production of the goods and

there is a rise in the exports of the products. It has ultimately raised the

national economy of the county and increased the standard of living of the

people.



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3D printers The process of rapid prototyping has acquired a new face due to the use of

the 3D printers. The 3D printers have fastened the process of rapid

prototyping leading to much more effective production. A 3D printer is used

for printing layer upon layer, which ultimately results in a three-dimensional

object. These layers are extremely thin which form the desired 3D object.

3D printing is believed to be a branch of rapid prototyping.

In the earlier days, the process of prototyping took long hours and tiring

days that sometimes affected the productivity and quality. Due to this rapid

prototyping came into existence that revolutionized the process entirely.

Many costs were incurred due to the labor that was hired and the various

equipments that needed to be used. However, due to the use of 3D

printers the process has become much cheaper and cost friendly. The 3D

printers now celebrate 7 years of their service in this field. The visualization

of the final product has also become easier thanks to the 3D printers.

The 3D printers use the method of additive fabrication. The material that is

used to construct the layers is of various types. It can be a sheet or liquid

powder depending upon the requirement of the object. The thickness of

every layer too is different as per the convenience. The resolution is decided

according to the thickness of the layer. The layers standard thickness is 100

microns. In the earlier days, the 3D printers were very small in size and

were found in offices. They were very easy to operated and also affordable.

However, today every machine that uses the method of additive fabrication

is called as a 3D printer.



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3D printers are of great use in various fields like architecture, engineering,

healthcare, entertainment etc. All these fields require the formation of 3D

models or objects in order to gain an insight into the final product and make

the necessary changes as required. The objects can also be shown to the

clients who can approve of it immediately or suggest the necessary changes.

This becomes easier when a 3D object is in front of them.

There are various types of 3D printers available in the market owing to the

growing demand of these machines. You can choose from a wide variety

according to your requirements. The shapes and sizes of the printers too

vary. A new type of 3D printer, which can copy itself, is under research.

However, this type of printer will soon exist due to the great research that is

taking place in this field. A 3D printer called RepRap is said to possess this

quality, which is yet in the development stage. These types of 3D printers

improve their quality by upgrading and downloading on their own and

thereby increase their own standards. So 3D printers are very beneficial

and have accelerated the process of rapid prototyping, which in turn will lead

to improvement all the aspects of the final product.



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3D printing technology The 3D printing technology is a great method used for printing 3D objects

at a faster pace and with better quality. It is a relatively new technology,

which is fast gaining popularity all over. It is used on a large scale today in

various fields. The 3D printing technology is all set to conquer the decade

with its efficiency and accuracy. 3D printing is a type of rapid prototyping,

which is used to create rough models of the final products. 3D printing

creates these three dimensional products before the design is finalized.

At the onset of 3D printing, there were only a few takers for this process.

This was due to the few hurdles like the expensive nature of the machines.

As the machines were custom made, it resulted in higher prices and thereby

less demand. However, this changed with time and people started using 3D

printing technology on a large scale. Various different processes were

used which lead to the origin of different types of 3D printers. Different

producers belonging to varied companies used methods like

Stereolithography, Selective Layer Sintering and Fused Deposition method.

The 3D printing technology has a number of benefits. This technology

enables colored printing and boasts of a great speed. The speed saves time

and also reduces the costs. Developing a 3D model would have been a very

expensive process depending upon the amount of work force hired and

various other costs of designing. However, due to 3D printing technology

the process has become much cheaper and fast. This technology is of great

use to the people in the advertising field, architects and professional

designers. All these fields make use of 3D models and thus it is very



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beneficial for them. Due to the low cost of this technology, students too can

use it for their various projects and models.

The quality of the 3D objects is also better and the objects are in a much

better shape. If you wish to circulate your product in the circle of the

investors or contractors then making the same model twice or thrice can be

a time consuming and expensive task. However, 3D printing technology

has made this possible and so you can create a number of similar models for

the purpose of distribution. It saves both time and cost, yet still the model

looks appealing to the eye. The material used to build the model is also

sturdy and hence is safe from any kind of damages.

The 3D printing technology is improving with every passing day and the

various ways in which it can be put to use are on the rise too. One of the

uses of this technology is in the field of biotechnology. Here the technology

can be used to print 3D images of the bones and other organs. The sizes and

shapes of the machines too are changing. The quality of 3D printing

technology is also expected to improve over the years and there are great

expectations from this technology.



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3D scanning and Prototyping Rapid prototyping has become a major industry in past few years. It is the

process of putting together a working model to test various aspects of a

design, illustrate ideas or features and gather early user feedback.

Prototyping is considered as an integral part of the system design process

where it is believed to reduce project risk and cost. Single or multiple

prototypes are made in a process of repetitive and incremental

development. Here each prototype is influenced by the performance of

previous designs in order to improve them. In this way, the defects or

deficiencies of the model are corrected. When the prototype is sufficiently

refined and up to the standards then it is send for production.

Rapid prototyping uses virtual designs from CAD (computer-aided designs)

or animation modeling software and transforms them into thin, virtual,

horizontal cross-sections or layers. Then these layers are transmitted to the

machine where one by one they are executed to form the design. The layers

corresponding to the virtual cross section from the CAD model are joined

together or fused automatically to create the final shape. Rapid Prototyping

is now entering the Rapid Manufacturing field so that we will have products

manufactured fast.

However, prototyping also requires good quantity as well as good quality.

Rapid Manufacturing manages the quantity part but the quality part remains

unsolved. Originally, prototyping has been developed to ensure that the

products which are geometrically complex and cannot be manufactured by



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machines, be manufactured using the prototyping method. Therefore, to

improve the quality of the product and make it possible to create more

complex geometric patterns, 3-D scanning is used.

A 3D scanner is a device that examines an object of the real world or

environment, collects data on its shape, size and appearance. Then this data

is used to construct a digital, 3-dimensional model of the object. Data, which

is, send into a modeling or CAD/CAM program is called “reverse

engineering”.

Hence, the data goes under the processes of prototyping and the product is

then produced. Therefore, the 3D scanner is used to analyze the data of the

object, and then is sent to the prototyping machine where it is layered.

Then these layers are executed and the product is obtained. In this way, 3D

scanning enables us to have details about the product in the prototype. You

can also have enlarged reproductions of the object.

The 3D scanning, digitizing and production process offers many

advantages. 3D laser scanning increases productivity by replacing time-

consuming prototyping methods like physical drawings, CAD programs and

reverse engineering. It also saves money, has precise accuracy and quality.

3D laser scanning and prototyping hence gives artists, sculptors, film and

video makers, industrial and product designers, ergonomic researchers and

costume designers the benefits of fast, effective and accurate models or

products for their use. They benefit greatly from this technique, which is

truly unique.



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Additive fabrication The method of additive fabrication came into existence nearly twenty

years ago and has become very popular since then. The method of

Stereolithography was discovered at the same time. Additive fabrication is

also known as rapid prototyping. Additive fabrication is still referred to as

rapid prototyping by a majority of people. There are various additive

fabrication processes which have been started to improve the quality and

efficiency of the models created. Additive fabrication means creating a

model with the help of numerous layers and different materials. This method

is used in the formation of various production parts, prototypes and tooling

components.

In the earlier days the method of additive fabrication was used to fasten

the speed of building the models. However, the speed was not that fast as

compared to the process today. Several changes took place over the years,

which led to the improvement of additive fabrication. The additive

fabrication process makes use of liquid, powder or sheet materials to build

the models. Metal, plastic or ceramic layers are produced one atop the

other. The prototypes formed through this process help in changing the

necessary details in the final product. Using the additive fabrication

process, numerous prototypes can be formed, each better then the previous

one. In this way, you can start with your final product, which boasts of

superior quality.

Today the additive fabrication process has been simplified for efficient use

and the parts too have become much durable and resistant. Using this

process many complicated projects and models can be built at a faster pace.



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This method is also beneficial for short run production in different

companies. Additive fabrication also helps in increasing the productivity of

the companies and saves time. There are three basic uses of the process of

additive fabrication. The first use is design and modeling. A rough design

of the final product is made using this process. The next use is fit and

function prototyping and another use is rapid manufacturing.

It is believed that additive fabrication processes are used only in the fields

of manufacture and industry where various objects are designed on a

regular basis. However, this process is also used in the fields of medicine

and healthcare. It is used for implants, surgeries, study the bones and

organs and other such purposes. There are various new developments taking

place in the additive fabrication processes that would prove to be helpful

in this field.

The face of the industries has changed drastically due to the use of the

additive fabrication processes. This process has helped scores of people all

over by reducing the time required for making prototypes and also reducing

the risk of errors and losses. However, one should follow the correct

procedures while using additive fabrication to benefit from the various

advantages it boasts of. Hence, the advantages of this process are many

making it beneficial for all genres of users. Additive fabrication process

has thus proven to be a boon for all and is on the path of further rapid

development to ensure better versions of additive fabrication.



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Advantages of rapid prototyping The process of rapid prototyping is fast gaining momentum especially among

engineers and people associated with different types of industries. Rapid

prototyping is an effective way to fasten the speed and efficiency of your

work. Prototyping is a very useful method of testing various products and

projects. It forms the basis of any kind of research or project. Rapid

prototyping is thus very beneficial and includes the designing of a rough

working model of the final project. Based on this rough working model you

can find out the shortcomings of your projects and overcome them. Due to

excellent advantages of rapid prototyping, it is fast catching the fancy of

a large number of people.

Some of the main advantages of rapid prototyping are-

• Rapid prototyping saves on costs and is thus cost efficient. It is thus an ideal method for all those related to the field of engineering and those in industries. Rapid prototyping helps in reduction of cost up to almost 50% which proves to be a good deal.

• Many of the projects and workings need funds for the efficient production and use. Rapid prototyping helps in gathering funds for this purpose and also provides the necessary concrete base and proof of the concept of the projects. As a result getting funds becomes an easier process as you already have a rough working model of your project.

• Different types of tests can be administered to ensure the proper working of the prototype. These tests also help in making the final product better and efficient. The product’s quality is also improved due to rapid prototyping. The user can also give accurate feedback which helps in improving the quality of the product.

One of the advantages of rapid prototyping is that it proves to be

effective in building the communication gap between the users and



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producers. Greater level of interaction takes pace between them leading to

better results. When you devise a rough prototype of your product you get

an idea of what and how the final product will look like. With the help of

rapid prototyping you can get a picture of your final product and also make

the necessary changes if required. The process is not at all time consuming

and in fact saves precious time making it a popular choice among many.

Due to all of these advantages of rapid prototyping, this process is

chosen by many people today. It is very helpful in increasing the quality of

the final product and thus satisfying the consumer easily. The process is also

inexpensive which makes it even more popular as there are no losses faced

in this process. The engineering charges too are reduced. Thus rapid

prototyping is indeed a trustworthy process which should be used by all the

people in this field. So make sure that you avail all advantages of rapid

prototyping and ensure maximum success of your product.



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Casting Prototype Prototype is derived from the Latin words 'proto' that means original and

'typus' which means model or form. The word prototype is most commonly

used as functional though it is an experimental version of the military

machines such as domestic appliances, automobiles and consumer

electronics. A prototype is used to manufacture units of a product to test and

make any changes in the design if necessary. The word prototype is used in

various fields such as Computer programming, Mechanical and electrical

engineering, Computer software engineering, Pathology, Metrology etc. In

every field, the meaning of prototype is different. Prototyping is a process of

creating a model of a system. Prototyping can reduce the cost of

development. As prototypes increases quality of communication between the

developer and the final consumer it is now used on a very large scale.

Organizations used prototyping of 30 percent of the time in development

projects while in the early 1990 the use of prototyping has doubled to 60

percent.

Application of Prototype results in better satisfaction of the user and exposes

all the developers to the future potential system enhancement. A prototype

helps you to detect any flaws in the design. It also helps the manufacturers

to know whether their invention is in the right shape, size and form.

Prototype casting is necessary when fast prototypes are needed to meet the

stringent projects deadline. The best advantage of using a prototype is that

it helps you to sell an invention or licenses it as it shows the actual working

of the invention. Through prototype, you can convey your best ideas of

invention. By using prototypes, the invention seems real to the examiner.



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Investment casting process offers you simple, low cost and very quick

turnaround solutions needed for your prototype requirements. It also gives

you great design freedom. The primary function of casting prototype is to

validate the process of production and design for casting. Secondly, it will

come to use ultimately to create casting in volume. Casting prototype is a

rapid prototyping that offers you finished casting in aluminum, zinc,

magnesium and many more.

Casting prototype is used to make complex shapes that are very difficult

to make by using other methods. Casting is divided into various forms such

as sand casting, plaster casting, casting prototype, investment casting,

continuous casting mold casting, centrifugal casting etc. Casting prototype

can be developed with the help of rubber plaster mold to have a superior

finish and a simulated die-casting. The use of green sand method used for

casting with the thicker sections diminishes or eliminates the porosity.

Prototypes are either produced with the help of plaster or air-set process.

This type of casting is used when finished and fine details become

necessary. For producing plastic molds, rubber patterns are used. By using

rubber patterns minimal or no cost is needed facilitating a cast to print part.

The costs of the machines are reduced if a cast is used to size the casting.

Sand is used to make very thick casting air-set as sand cools down the

metal very fast thus eliminating reduction in size and porosity.



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Designing and Prototyping Prototype can be called as a draft version of website. You can explore your

ideas before investing time and money into development with the help of

prototype. Prototype can be a series of drawings on paper, known as a low-

fidelity prototype. It can even be a few images or pages that the user can

click through. It can also be a fully functioning Web site known as a high-

fidelity prototype. You should use low-fidelity prototypes, as paper-based

prototyping is the quickest way to get feedback on your preliminary site

architecture, design, and content. Designing and prototyping go hand in

hand and are complementary to each other.

The meaning of designing and prototyping is different to different people like

a pattern, a wallpaper, the appearance of a racing car and so much more.

The nature of design is as complex as that of technology. It is done with

hands on experience, knowledge and skill, which deal with our ability to

mould our environment to suit our material and spiritual needs. If the

designers have design patterns then it can help them to solve the complex

design problems with ease. For the varying designing issues there are many

design patterns like object composition, perspective of the object creation

and object behavior.

The Prototype pattern is a creational design pattern. It helps to create the

deeply copied objects by using the existing objects created in the

application. This reduces the work of writing the repetitive code of creating

and then copying the object state to the new object. Prototype design

pattern is a complex job, as it needs to create the deep copy of the object.

The work of creating a deep copy of the complex object composition is



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simplified by using prototype design pattern. This is only possible if every

object in the composition implements ICloneable interface. For copying the

objects like tree, designing and prototyping proves to be very useful.

All new objects created by using the clone method reflect the exact object

state of the original object. If several objects of the same structure or class

are created by referring the class constructor and thereafter initializing every

property unambiguously for each object can lead to increase in the number

of recurring lines required to properly initialize every property of every

object created. By using this pattern, the requirement for initialization can

be abridged significantly. You can always produce a clone of the existent

object that is developed in the application to have the objects readily

initialized to the default or non-default state.

One object that is created in the system and then initialized to the default or

non-default state is enough to create the similar object copies repeatedly.

We do not need to write the code repeatedly to initialize the rest of the

properties if there are only a small number of properties that disagree from

object to object. This will optimize the efforts of writing the code to initialize

the properties that are different between objects of the same class or

structure. It makes the program structure easier to understand and maintain

as the object copying is done algorithmically by calling upon the Clone

method on all constituent composition objects. Thus, designing and

prototyping is very interesting and is being used on a large scale.



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Disadvantages of Rapid Prototyping Rapid prototyping has gained popularity over the years. However, there is a

contrast view when it comes to rapid prototyping that is in vogue. Every new

technology has its own pros and cons, so even prototyping remains no

exception. Therefore, this article tries to elaborate on the disadvantages of

rapid prototyping.

Many people view prototyping as one that may exclude other design ideas

because of the rush to prototype rapidly. The design features may also be

limited by the scope of the prototyping. The capital costs are also very high,

the tolerance >.005”, the primary materials are specialized and various

other steps are required to produce metal parts. These can be considered as

some of the disadvantages of rapid prototyping.

As Rapid prototyping is becoming a basic step in the design of complex

systems, the user interfaces are becoming increasingly difficult to program.

Hence, rapid prototyping tools are not being able to keep up with the user

interfaces. Therefore, the tools produced can replicate the function that we

want but they are difficult to use. To reduce the risk of using a poor

prototyping tool you need to carefully evaluate the tools and use the one

that best suits your purpose. Your needs may include specific functions,

operating systems, programming languages and ease of use. If no tool

meets your needs then you may have to compromise your needs to suit the

tool. It is vital to be able to change the prototype quickly and easily to

stimulate every feature of the proposed product. The disadvantages of

rapid prototyping can hence cause a hindrance in your product

manufacturing.



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The difficulty in using the prototyping is leading to programmers operating

the tools rather than the domain experts, information developers,

marketers, planners and usability representatives. You can reduce this

problem by having your prototyping teamwork closely. Teammates who are

familiar with customers can help the programmer by adding value i.e. by

using the language which customer understands. Also, prototyping, being a

dynamic and informal process, requires feedback at regular intervals.

Offhand comments on how to change the product can lead to its

development. However, having the customer to write down a Design Change

Request is a way to make ensure that the customers keep giving consistent

and valuable feedback. Therefore, the disadvantages of rapid

prototyping also involve managerial problems.

The prototyping tools are grouped in two categories. The first one is that the

prototype user interfaces quickly but does not produce reusable code. The

second group lets you produce the reusable code but creates prototype user

interfaces that are difficult to revise. Both these types are different and have

mutually exclusive purposes but that disables you from having prototype

tools that user interface quickly and let you use the reusable code. The

prototyping tool lacks an obvious stopping point. A dedicated team also feels

that they can improve their product even more. In this way, the

disadvantages of rapid prototyping seem great and can indeed so if you

do not employ proper practices.



Page 27

The rapid prototyping also has its flipside. Hence, the user must be aware

about these before he/she uses the tools. There are certain disadvantages

of rapid prototyping but it remains a popular technique.



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DIY Rapid Prototyping - Home Made 3D

Printer The DIY Rapid prototyping - Home made 3D printers are fast gaining

popularity all across the globe due to their effective use and improved

quality of products developed from the 3D printers. There are many types of

3D printers available in the market and you can choose the one suiting your

needs. 3D printers are quite beneficial in various fields like architecture,

engineering and industry. However, these printers can also be of great use

at home. A 3D printer can now be easily manufactured at home by following

a few simple design ideas.

In case you do not wish to opt for a printer from the market, you can always

build your own printer at home. You can use the machine to print the 3D

images of your projects. There are plenty of people who have been able to

devise plans for development of 3D printers at home.

There are various creative ways of building your on 3D printers. A group of

DIY people is believed to have come up with a constructive way of building a

3D printer. These people mostly belong to Russia and they have managed to

build their own printers. Sometimes the cost of a 3D printer may be very

high depending upon the quality and materials used while building the

machine. However, if we use cheaper materials and free software we can

save the cost of production and make our own DIY rapid prototyping -

home made 3D printer with great ease.



Page 29

Therefore, this proves that a printer can be built using basic and cheap

materials, which in turn also helps reduce the overall cost incurred. The

printer built by them used the software called stereolithography CAD file.

Plastic waste was also used which proved to be very cheap. You can even

use any type of powdered paint as a raw material, which is also available at

affordable rates. Sometimes the 3D printers available in the market are not

always affordable to people sitting a home hoping to use these printers for

important purposes. So you can opt for DIY Rapid prototyping - home

made 3D printer built with the help of various materials. These printers will

help you in downloading and printing three-dimensional objects.

While making the 3D printer you should check the materials you are using

and make sure that necessary precautions are taken in case of hazardous

materials. There are basic materials like clay or play dough and silicon. One

of the methods of building the printer is making use of edible materials like

sugar which helps in the printing process. Some of the 3D printers built at

home previously made use of a technology called selective hot air sintering

and melting.

There are various websites, which can help you in understanding the

procedure of building 3D printers at home. These websites have easy and

hassle free methods, using which you can make your own 3D printer at

home. The various procedures are described in a detailed manner. You can

follow the steps given on the website and successfully make your 3D printer

at home. It also helps in unleashing your creativity. So DIY rapid

prototyping - homemade 3D printer is very beneficial and people have

started experimenting with this 3D printer on a large scale.



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Electron Beam Melting Electron Beam Melting (EBM) is a type of rapid manufacturing method. It

is a solid form of fabrication used to create solid metal parts directly from a

CAD file. This technology is used to manufacture parts by melting the metal

powder layer by layer with the help of an electron beam in a very high

vacuum. This technology of electron beam melting makes use of the parts

that are void free, very strong and solid. It is also referred as Electron Beam

Machining. A solid metallic object is directly created from the metal power by

using this technology.

In this technology, a design is prepared by using three-dimension CAD

program for the part, which is to be developed. The model is then sliced very

finely of approximately a tenth of a millimeter thick. A very thin layer of

power like the model is scrapped. It is adjusted and placed on the vertical

surface. Through the powdered layer, the geometry of the first layer is made

by melting together all the points directed by the CAD file with the help of a

controlled computer electron beam. After this process, the surface of the

building is lowered to the level as to the thickness of the powder layer while

another layer is placed upon the previous layer. This same procedure is

repeated until the metal part is completed from the CAD model by bonding

together layer after layer.

The application of advanced computer controlled Electron Beam Melting is

very useful in the vacuum as it provides very high quality and precision.

Fabrication of the homogeneous metal components like the complex tooling

used for the spray-forming, injection molding tools and the functional

prototype in a very short period of time is possible by the use of this



Page 31

technology. By this method, the production process is completed very fast as

compared to the conventional manufacturing methods. Unlike other additive

fabrication methods, this system creates parts three to five times faster from

the titanium powder. One of the advantages of using this system is that it

diminishes the reworking on the part. In comparison, the Electron Beam

Melting produces void free parts by completely melting the metal particles.

This procedure takes place in a very high vacuum that makes sure that the

part is completely solid without any imperfection caused by the oxidation.

This system is applicable and very useful where a high temperature and

strength are required. This device develops parts to wrought the titanium in

better ways than the cast titanium with a recovery of 95 percent of the

power. With the application of Electron Beam Melting the manufacturers

of automobile can build strong parts for testing high temperature by

including the under-the -hood applications. Also, the engineers of the

aerospace interested in the combination of strong strength with a lightweight

titanium part can be benefited by the application of this system. The EBM

process creates homogeneous solid parts that can be flight certified. This

process makes use of 95 percent of the high power electron beam that is 5

to 10 times more than a laser beam.



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Fused Deposition Modeling Fused Deposition Modeling is often abbreviated as FDM. It is a

manufacturing process or a type of rapid prototyping, which is used for

creating engineering designs. The fused deposition technology was

developed in the late 1980’s and became quite popular in 1990. This

technology is developed on the principal of constructing layers upon layers.

It is a very useful means for construction purposes, which make use of solid

freedom fabrications. Three-dimensional objects can be created easily with

implementation of Fused Deposition Modeling. This process is generally

found in those industries where short-run parts are produced in large scale.

This process makes the use of metal wire or plastic filament (metal material

or the filament used is unwound from the coil) which is connected to the

extrusion nozzle to regulate the flow. The material is melted with the nozzle

because of this it can move swiftly in vertical and horizontal directions with a

numerically controlled mechanism. This mechanism makes use of Computer

aided software packages. A thin layer of beads of extruded plastic is

deposited when the nozzle is moved over the table. The plastic hardens

quickly as soon as it is squirted from the nozzle and layer over layers are

formed. This whole system is enclosed in a chamber and a temperature,

which is below the melting point of plastic.

ABS and casting wax are the commonly used materials for the process as

they offer good strength. With the boost in the scientific and technical fields,

materials like polycarbonate and poly (phenyl) sulfone are used which help

to increase the capabilities of the method. The strength and temperature

range is increased drastically by the use of these materials. Fabrication of



Page 33

the support structures is made for over hanging geometries. Later the object

is separated by breaking it or by exposing it to water-soluble materials.

Fused Deposition Modeling method is very simple to implement and

execute. It is a very quiet and office-friendly method. It is a high-speed

method that yields quick results and is also favorable for small parts. It

helps to boost the execution speed and minimize the errors. However, for

parts with cross section it takes longer execution time. With rapid increase in

technology, this method has under gone many significant improvements.

With the implementation of Fused Deposition Modeling, the finished parts

produced have shown great amount of improvements. This technology is

mainly found in commercial printers. By the year 2003, this technology

gained a vast popularity and its implementation was done on large scale in

various fields.

FDM Titan, FDM Vantage, Prodigy Plus, FDM Maxum are a part of Fused

Deposition Modeling. Thermoplastics like Abs i.e., ployphenylsulfone, ABS

and polycarbonate are used in the FDM method. The heat resistance is

drastically increased by use of these materials. The Fused Deposition

Modeling is not used in the display models, as it does not yield high details.

However, this technique is commonly used for finalizing the product or by

functional testing departments. Nowadays with improvements in the FDM

model, this method is being employed in fields where micro gravity is used.



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Laminated Object Manufacturing Laminated Object Manufacturing is a type of rapid prototyping system.

In this process papers coated with adhesive, plastic or metal are glued

together in layers and cut in shape with the help of laser cutter or with knife.

Helisys Inc. developed Laminated Object Manufacturing. It produces

larger volumes of models that are more economical than various other rapid

prototyping methods. This technology is used mainly in Vacuum tooling,

Vacuum forming, Sand casting, patterns and Replication masters.

Laminated Object Manufacturing is a system used for forming plurality of

laminations in the stack to develop a three dimensional object. This system

consists of an X-Y plotter machine, which includes a tool for forming a layer

on the sheet of material, which is placed on the worktable.

The process of Laminated Object Manufacturing is performed in a

systematic form. First, the paper is cut in the form of cross sections using

CO2 laser and then the paper is unwound on the stack from the feed roll and

is glued together to the previous layer by using a heat roller. The heat roller

from its bottom side to create a bond melts the plastic. Optics system traces

the profiles of object cross sections that are mounted to a stage. A charcoal

filtration or a chimney is necessary as smoke is generated during this

process and the build chamber must be sealed. The surplus paper is then cut

away after considerable geometric features of layers are formed. This excess

paper is cut to separate it from the web and it is then folded up. The cross

sections are heavily crosshatched by using a laser for its removal. Removing

the excess material to gain some geometry is very time consuming.



Page 35

The process of Laminated Object Manufacturing may not give a desired

finish and accuracy like other methods. This system consists of a reference

frame, which consists of two rigid beams placed on the base of the frame.

There is a sensor between the tool and the reference frame to sense the

force that is applied to the lamination by the bonding tool and thereby adjust

the height of the worktable. The temperature of the layers is sensed by this

infrared sensor to give a feedback to the control device for adjusting the

speed of the bonding tool. In the Laminated object, manufacturing

system the forming tool may be a laser system that consists of a laser that

is placed on the reference frame or a plurality of the mirrors or the lens that

is placed on the X-Y plotter machine.

The advantage of Laminated Object Manufacturing is its ability to

develop models on a very large scale by using inexpensive paper material.

The materials used in this process are Eco-friendly and do not harm health.

Laminated Object manufacturing has some disadvantages like it needs

decubing which is very time consuming and needs labor for an “automated”

process. The smoke emitted while carrying out this process can cause

trouble to visitors or people living nearby.



Page 36

Prototyping vs. rapid prototyping If you want to compare prototyping vs. rapid prototyping, you should

clearly know about both these terms. Prototyping is a process of creating a

model of a system. The prototypes can be used to help the system designers

to develop an information system, which is quite easy to manipulate for the

end users. Prototyping can be called as a process, which is a part of analysis

phase of the systems development life cycle. Rapid prototyping is a group of

techniques that are used to fabricate a scale model of assembly or part

using the three-dimensional computer aided design (CAD) design. It is also

known as solid free-form manufacturing, layered manufacturing and

computer automated manufacturing.

Rapid prototyping technique was introduced during 1980s. Today, it is used

to decrease the costly mistakes, to diminish supporting engineering changes

and to expand the product’s lifetime by the addition of essential features and

elimination of superfluous features early in the design. Prototyping is

considered as an integral part of the system design process and it helps to

reduce the risk and cost of the product. Generally, one or more prototypes

are involved in the process of iterative and incremental development. In this

process, each prototype is influenced by the previous designs and the

problems in that design are corrected.

While thinking about prototyping vs. rapid prototyping, you must

understand the benefits and disadvantages of both. The advantages of

prototyping are it may give a proof of concept that is needed to attract the

funds. Early visibility of the prototype can give the idea about the

appearance of final system to the users. Prototype can encourage active



Page 37

participation among the producer and users. It enables a higher output at

low costs as well as it improves the system development speed. It can help

to identify the problems with requirement analysis, efficacy of earlier design

and coding activities. Prototyping can help to refine the possible risks related

to the delivery of the system that is to be developed. With the help of

prototyping, the developers can receive quantifiable user feedback. Overall

result of using prototyping is higher user satisfaction.

The reason for comparing prototyping vs. rapid prototyping is that there

are some disadvantages of prototyping. The prototype may not meet all

requirements of the user. There may be a chance of leaving the system

unfinished. It is possible that the systems will be implemented before they

are ready. The producer may develop a system that is not able to meet the

requirements of overall organizations. Since many changes might be made

with the system, the structure of the system may get damaged. This

technique is not ideal for the large applications.

While comparing prototyping vs. rapid prototyping, you will come to

know that the disadvantages of prototyping can be overcome by applying

rapid prototyping techniques. There are several benefits of using rapid

prototyping technologies. Major rapid prototyping technologies are

Stereolithography Apparatus (SLA), Selective Laser Sintering (SLS), Fused

Deposition Modeling (FDM), Solid Ground Curing (SGC), Laminated Object

Manufacturing (LOM), Inkjet Technology, Direct Shell Production Casting

(DSPC), Direct Metal Deposition (DMD), PMD flat wire metal deposition

technology and 3D Printing.



Page 38

Rapid prototyping is used to increase effective communication and to

decrease the development time. It can help to reduce several uncertainties

about the design of a new product. It provides the designers with better

physical as well as visual understanding of the product. It can be used to get

better understanding of the type of product required at the early stages of

development, which can help for improvement in the design.



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Rapid manufacturing The increased competition has lead manufacturers around the world to face

the challenge of delivering new customized products more quickly to meet

the customer demands. The delayed development or delivery can be a

business failure. There are several technologies, which are collectively

known as Rapid Manufacturing (RM) that has been developed to shorten

the design and also to revolutionize many traditional manufacturing

procedures.

Rapid manufacturing includes the fast fabrication of the tools required for

mass production. Rapid Prototyping traditionally has been used for making

parts that are used in the design or testing phases. Rapid manufacturing

goes a step further and makes the finished item that will be used by the end

user. The newly developed layer manufacturing techniques are using

increasing ambit of materials. The products produced using RM, have

increased in size and durability and the quality is also very good. As a

result, layer manufacturing is being used more and more frequently to

fabricate the parts both for production tools and for functional prototypes.

The layer manufacturing system was first intended primarily for rapid

prototyping application. All layer-manufacturing processes consist of a

computer CAD system with an operation machine to perform the fabrication

of a layer under the computer control. A 3D CAD representation is created

by a computer software package such as ProEngineer, SolidWorks or

Autocad. The computer representation is then sliced into layers of certain

thickness. Their 2D profiles are stored in a triangulated format as a STL file.

Then the software coverts the STL data to machine data and further to the



Page 40

operation machine where the specific fabrication process generates each

layer. This process is repeated for all the layers and hence the part is built

layer by layer. The final step is to remove the part from the machine, detach

the support materials and perform any necessary cleaning or surface

finishing.

The benefits of rapid manufacturing are that it eliminates the creation of

any tooling and tooling costs, which are usually high. Also, the involved cost

of production is low. The production speed and the time to market are also

short, thanks to rapid manufacturing. An item that is typically created

with rapid manufacturing has the following characteristics. It is small in

size, deals with low quantity, and was previously made with low volume

injection molding, epoxy or aluminum tooling. Also it has limited product life

span and the geometry is such that cannot be made using traditional

manufacturing methods. Due to the arrival of rapid manufacturing, the

supply chains are facing tremendous changes. The manufacture is not

constrained any more as it used to be because of the availability and

location of tooling.

The number of commercial Rapid Manufacturing (RM) systems for various

materials and sizes are now available on the market around the world in

great numbers. These technologies have developed and improved in

capability and have been in widespread use for well over half a decade. The

success attributed to Rapid Manufacturing by practical verification is really

praiseworthy. We will see further development and application in this field of

Rapid Manufacturing in the future for sure.



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Rapid Prototyping Rapid Prototyping is a computerized device that creates a model directly

from a CAD drawing by building it layer upon layer. It is a process of quickly

turning a design of a product into physical samples. In the year 1980 the

first rapid prototyping process was developed. Rapid prototyping is also

known as three dimensional printing, additive fabrication, solid fabrication

(SFF) and layered manufacturing. It is a method that is used to add and

bond materials together in layers to form various objects. Rapid

prototyping is considered as one of the best manufacturing processes to

develop small production and complicated objects. All most all the

prototypes need minimum three to seventy-two hours to create an object

depending upon the size and the complexity of the object. Rapid

prototyping is a very advanced technology that directs the computer for

converting the designs from the computer representations directly into solid

objects with no human intervention.

There are various uses of rapid prototyping such as they serve as very

good visual aids to communicate the different designs with customers and

co-workers. Rapid prototyping is also used to design testing. Moreover,

they are used to make tooling i.e. rapid tooling and also to produce quality

parts. There are numerous rapid prototyping techniques available but

there are few basic steps, which are used commonly such as to create a

model of CAD for design and then converting the CAD model of design into

STL format. After going through this procedure slice the STL file into a very

thin layers of cross section and construct the model by adding one layer

upon another. After creating the model clean it and give it a finishing touch,

which is very important.



Page 42

Rapid prototyping is used on a very large scale in automotive, medical,

aerospace and in the consumer product industries. The basic use of

prototype is for communication and testing purposes. It improves

communication between people such as engineers as they find three-

dimensional objects very easy to understand than the two dimensional

drawings. It is also useful for testing design to observe whether it performs

as per the desired needs or if it needs some improvements. The automatic

fabrication to produce quality machine tool is called rapid tooling which is

one of the most expensive and slow processes in the process of

manufacturing, as it requires an extremely high quality. Thus, manufacturers

use rapid prototyping to increase the speed of the manufacturing process.

Industrial firms can save both the cost and time in the process of developing

the product with the use of rapid prototyping. It is proved that about 60 to

90 % of time can be saved by using rapid prototype. It benefits the

manufacturer to reduce the many uncertainties that come in the way of

manufacturing process. It helps the developers to be more flexible and

creative in developing various new products. Rapid prototyping is

considered to be very important in various stages of the manufacturing

process. Rapid prototyping techniques help the developers to come out

with quality products.



Page 43

Rapid Prototyping Overseas Prototyping is the procedure of building a model of a system. It helps the

system designers to build an information system that is intuitive and easy to

manipulate for end users. An iterative process is a part of the analysis phase

of the systems development life cycle. A systems development method

(SDM) in which a prototype is built and tested is known as Prototyping

model. Then it is reworked as necessary until an acceptable prototype is

finally achieved by which the complete system or product can now be

developed. An iterative, trial and error process takes place between the

developers and the users. There are many forms of prototyping such as from

low tech sketches or paper screens (Pictive) from which users and

developers can paste controls and objects, to high tech operational systems

using CASE (computer-aided software engineering) or fourth generation

languages and everywhere in between. Rapid prototyping overseas is thus

an interesting feature of the prototyping process.

Rapid Prototyping (RD) means a host of related technologies that are used

to fabricate physical objects directly from CAD data sources. This method is

unique because they add and bond materials in layers to form objects. This

system is also known as three dimensional printing, layered manufacturing,

additive fabrication and solid freeform fabrication (SFF). These machines can

produce prototypes in a very short time. It is used for testing and verifying.

Moreover, it is also used for the production of ‘short run’ parts where

multiples are produced without traditional tooling and molds being required.

To maintain global competitiveness the World Wide Web (WWW) and

Internet are being hyped as necessary for all organizations. The key

activities include a wealth of interactive free information, global

communications, the freedom of information, and a shop-window to publicize

your organization. Rapid prototyping overseas (RP) had a major impact on

http://www.colorado.edu/infs/jcb/class/analysis.html

http://www.colorado.edu/infs/jcb/class/sysdevel.html

http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci1000947,00.html



Page 44

the manufacturing industry in the UK and all over the world. Currently there

are 6800 machines all over the world and in the year 2000, these produced

a staggering three million models and prototype parts. To produce this is a

huge number of parts from a class of technology that has only been

available for little more than a decade.

Rapid prototyping overseas is fast gaining popularity and is existent in many

countries. One of the professional prototype makers in the toy industry is A-

Tech Product Engineering Company (A-Tech), based in Hong Kong. In

addition, there are two main factories in Shenzhen, South China. At first

about 4 years ago, they learned of the SensAble™ FreeForm® Modeling

Plus™ system and then implemented this unique system - a 3-D touch

enabled Computer Aided Sculpting System (CAS) - into their workflow.

Originally, in the United States, the client who uses freeForm modeling plus

system recommended that they use it as a modeling tool that helps improve

communication concerning designs beyond the Pacific region. In China when

other groups become familiar with the system, they also started to share the

system. In A-Tech Company, it includes two more Rapid Prototype makers.



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Rapid prototyping services Rapid Prototyping services (RD) mean a host of related technologies that are

used to fabricate physical objects directly from CAD data sources. This

method is unique because they add and bond materials in layers to form

objects. This system is also known as three dimensional printing, layered

manufacturing, additive fabrication and solid freeform fabrication (SFF).

Now, additive technologies offer advantages in many applications compared

to classical subtractive fabrication methods such as milling or turning.

The rapid prototyping services prove to be extremely useful. Rapid

Prototyping is the most advanced method for quickly creating a prototype.

This can be done with the help of rapid prototyping machine. These

machines can produce prototypes in a very short time. It may take

anywhere from a matter of hours to a few days for its completion depending

on the complexity of the prototype.

Rapid Prototyping services help to visualize models better and thereby

increase communication. With the help of these services, you may test and

verify your design for fit and function. It also decreases development time

and hence time to market. It also helps to avoid costly manufacturing

mistakes. Rapid prototyping is not only used for testing and verifying but

also used for the production of ‘short run’ parts where multiples are

produced without traditional tooling and molds being required, this is called

as Rapid Manufacturing.

Rapid Prototyping grows a part using a Rapid Prototyping machine and a

Computer-Aided Design (CAD) model to create a physical model using an

additive method, layer by layer. There are varieties of materials available.

Its use depends on the specific method of Rapid Prototyping equipment that

is used. These materials include resin, metal, plastic and wax. Machining



Page 46

processes like CNC milling use a subtractive technique, where the material is

removed from a solid block to create the part.

First computer-aided (CAD) model is constructed. Then it is converted to STL

(Standard Tessellation Language which is native to CAD software) file

format. STL file is the standard interface between the Rapid prototyping

machine and the CAD software. The Rapid Prototyping machine reads STL

file and it creates cross-section layers of the model. When the first model is

created, the next layer is added at the thickness determined by the Rapid

Prototyping machine and the process is iterated until the complete model is

built. The selected users from the stakeholder groups participate in a

brainstorming session to test the prototype. Then the user’s observation are

summarized and evaluated. Wherever necessary the prototype is refined and

if required, this procedure is also repeated.

To correspond with supervisors, customers, manufacturers without

communication barriers the inventors and product development teams use

rapid prototyping services. Prototypes help to ensure projects run as quickly

and cost efficiently as possible, so it is an important part of the design-to-

market process. It is also used in communicating with manufacturers

(especially over seas), to attract investors, customers and in consumer

marketing focus groups. It is much easier to communicate an invention or

design by using a 3-D prototype than with a drawing or blueprint.



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Rapid Prototyping Technologies The term Rapid Prototyping (RP) refers to a group of techniques that are

used to fabricate a scale model of assembly immediately or part using the

three-dimensional computer aided design (CAD) design. RP is also known as

solid free-form manufacturing, layered manufacturing and computer

automated manufacturing. It is the method of creating physical objects by

using solid free form fabrication. The use of rapid photocopying techniques

started during 1980s and it was used to build the product models. Today,

rapid prototyping technologies are used in a wide range of objectives.

Rapid prototyping is used to increase effective communication, decrease the

development time, to decrease the costly mistakes, to minimize sustaining

engineering changes and to extend product lifetime by the addition of

necessary features and elimination of redundant features early in the design.

Rapid prototyping technologies can help to reduce several uncertainties

about the design of new product. It provides the designers with better

physical as well as visual understanding of the product. It can be used to get

better understanding of the type of product required at the early stages of

development, which can help for improvement in the design.

Today, plenty of rapid prototyping technologies are available in the

market such as Stereolithography Apparatus (SLA), Selective Laser Sintering

(SLS), Fused Deposition Modeling (FDM), Solid Ground Curing (SGC),

Laminated Object Manufacturing (LOM), Inkjet Technology, Direct Shell

Production Casting (DSPC), Direct Metal Deposition (DMD), PMD flat wire

metal deposition technology and 3D Printing.



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Stereolithography Apparatus (SLA) features the use of UV laser to detect a

cross section of the product model layer by layer across the top of vat of

liquid polymer. It can harden a thin layer of the material. As each layer is

detected, the object is slightly lowered so that the laser can determine the

next cross-section of the object in the polymer and then solidifying that layer

attaching it to the previous layer. This process is continued layer by layer

until the object is completely formed.

Selective Laser Sintering (SLS) is among the important rapid prototyping

technologies, which uses a laser to combine the thin layer of powdered

material into the solid object. Once one layer is completed, a thin layer of

the powdered material is spread over the top of that layer so that it gets

fused with the next layer. This technique is useful for fine details and thin-

walled parts.

Fused Deposition Modeling (FDM) is one of the popular rapid prototyping

technologies that use a temperature-controlled head to deposit the

thermoplastic material based on CAD cross-section slices. The material is in

a semi-liquid state, starts bonding to the previous layer, and becomes hard.

Bu using the Solid Ground Curing (SGC) technology, you can print each CAD

cross-section slice on a glass photo mask with the use of electrostatic

process such as a photocopier. A UV light shines onto a thin layer of polymer

through the mask and then hardens the exposed resin. Liquid resin is then

vacuumed off and liquid wax is spread onto the spaces if any, which is later

removed. After cooling, this layer becomes solid and thick. The same

process is repeated with the next layer to build up the part.



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Laminated Object Manufacturing (LOM) begins with a thin layer of about 4-8

mm of sheet material. It involves the use of a laser for cutting the first CAD

pattern that is based on a part cross-section. A blank sheet with a dry

adhesive on its backside is then rolled across the cut layer and then is

attached by applying the heat. The cutting process starts again on that

sheet, through which the parts having relatively thick walls are built.



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Reverse engineering Reverse engineering, as the name implies, is to reverse the process of

engineering. In engineering, you design an object and then put it together.

However, here, you take it apart, see how it works in order to duplicate or

enhance it. This practice is taken from older industries and is incorporated in

the computer hardware and software industry.

Originally reverse engineering was used only for hardware. Hardware

reverse engineering involves taking apart a device and seeing how it works.

Reverse engineering is now also applied to software, databases and even

human hair. Programs are written in a language like C++ or Java, which can

be understood by programmers. However, when they are implemented on

the computer, they have to go through a compiler and hence are transferred

into the 0s and 1s computer language. The compiled code is

incomprehensible to most programmers. Therefore, you can use reverse

engineering in this case to find out the original program written in

understandable languages.

In software, reverse engineering the machine's code (the string of 0s and

1s that are sent to the logic processor) is sent back to the source code that

it was written in with the help of language statements. Software reverse

engineering is done to retrieve the source code of a program because the

source code is lost, to study how the program performs certain operations,

to improve the performance of a program, to fix a bug, to identify a virus

and the likes.



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Reverse engineering has many purposes, which include it being used as a

learning tool, a way to make new and compatible products, which are

cheaper, to make software interoperate more effectively or to bridge data

between different operating systems or databases and to uncover the

undocumented features of commercial products.

Another sort of reverse engineering involves creating 3-D images of

manufactured body parts whenever blueprints are not available for

remanufacturing the required part. To reverse engineer that part, it is

measured using a coordinate measuring machine (CMM) while a 3-D wire

frame image is dimensioned. The physical object can also be measured using

3D scanning technologies like CMM's, laser scanners, structured light

digitizers and computed tomography.

It is used in businesses to bring existing physical geometry into the digital

product development environment, to make a digital 3D record of their own

products or to assess competitors' products. Data reverse engineering (DRE)

is defined as the use of structured techniques to reconstitute the data assets

of an existing system. DRE provides a structure, which permits data

engineers to reconstitute specific organizational data requirements and then

implement processes guiding their resolution. DRE is a relatively new

formulation of systems re-engineering technologies and therefore, most

organizations are unaware of DRE as a technique and practice less

structured approaches in response to data challenges.

Therefore, reverse engineering has become an increasingly important

aspect of fields like software and hardware engineering. The use of data,



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system and processes reversal has become vital in data recovery, software

correction and enhancement. All the industries are slowly benefiting from the

advent of reverse engineering and hence the software, hardware or data

can be easily modified and corrected.



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Selective laser sintering The selective laser sintering stations (SLS) use thermoplastic materials or

metal powder to create 3D prototype parts. A computer-directed heat laser

melts powder layer by layer. More powder is deposited on top of each

solidified layer and again sintered.

The selective laser sintering allows for more diversity in the selection of

materials. These include nylon, glass-filled nylon, polycarbonate, metals,

elastomers, SOMOS (rubber-like) and Truform (investment casting). Hence,

the SLS process provides for the most functional rapid prototype available.

A typical selective laser-sintering machine consists of two powder

magazines on either side of the work area. The leveling roller spreads the

powder from one magazine crossing the designated area to another. Further,

the laser outlines the layer intricately. The work platform moves down by the

size of one layer and then the roller moves in the opposite direction. The

laser beam traces the surface of powder that is tightly compacted to

selectively liquefy and bond it to create a layer on the object. Until the part

is complete, whole process is repeated. The temperature of the fabrication

chamber is maintained just below melting point of the powder and so the

heat of the laser only raises the temperature slightly so as to cause

sintering.

To prevent possible explosion in handling large quantities of powder the

fabrication chamber maintains a nitrogen atmosphere, this speeds up the

process. When the object is fully formed piston is raised to elevate the



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object. The excess powder is simply brushed off and the final finishing of the

object is carried out manually. However, the part needs to cool down and

hence has to be kept in the machine until that happens. The large parts with

thin sections may even require two days as cooling time. The selective

laser sintering method is also being used for direct fabrication of metal or

ceramic objects and tools.

The materials used in this process are used according to their intended

purpose. DuraForm is used for functional plastic parts, DuraForm GF is used

for glass-filled functional plastic parts, Somos 21 is used in durable

elastomer parts, LaserForm A6 is used in metal and tooling and CastForm PS

is used in casting patterns.

Selective laser sintering offers the advantage of making functional parts

in final materials, i.e. the object to be made is made in the material in which

it is to be sold. The system is more complex than stereolithography and

most other technologies. Also the SLS has the capacity to make metal

prototype parts using Rapid Steel A6 or Laser Form ST-200 materials where

metallic powder is used in the laser sintering process. However, the

disadvantages of SLS are that the object is porous and hence it has to be

filled with a sealant to make it functional.

Therefore, selective laser sintering has given the world a fast and

effective way to make prototypical objects. The advantages of the SLS

process are great and it has relatively less disadvantages. SLS is a better

way of prototyping than stereolithography.



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Stereolithography Stereolithography abbreviated as SLA is a process of Rapid prototyping. It

is used for the production of three dimensional and physical objects like the

conceptual models or the master pattern. It is often referred with the names

like 3-D printing or 3-D layering. The three-dimensional or the physical

objects are created with the aid of CAD drawings. It uses the method of the

CAD drawings that assist the mechanical engineers to verify certain parts

and have a visual idea about their products. It is also beneficial for inventors

as they can get an estimate for their future inventory products. 3-D printing

technology is very useful in the 21st century in all the sectors. With the

invention of Stereolithography, workload of several companies has

reduced and there is an increase in quality and production of goods. The

machine of Stereolithography is aided by the computer to create 3-D parts

and is based upon the method of layers.

Stereolithography makes use of liquid UV curable resin. It also uses a UV

laser, which is used to build layers over layers. On the surface of the resin, a

laser beam traces the part of the cross section pattern. The pattern or part,

which is traced, is hardened when exposed to the UV laser light. Once the

part or the pattern is solidified, the elevator of Stereolithography descends

by single layer. The thickness of the layer is generally between 0.05 mm to

0.15 mm. The resin-filled blade swipes the cross section part and later it is

re-coated with new materials. Adhering to the previous layers, the

subsequent layer pattern is traced and this leads to the formation of the 3-D

part. The excess resign on the parts is cleaned with chemical bath. Once it is

cleaned properly, then it is cured in the UV oven.



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There is a drastic increase in the geometric visualization of the product. The

complex factors in the product are curbed with the use of this technology, as

one can easily understand the layout of the products. The process is time

saving and result oriented. It yields quick results and helps to minimize the

errors. The support structures that are attached to the elevator platform are

used in Stereolithography. This helps to over come the deflection of

geometry due to gravity and also helps to hold the cross section of 2-D. For

the use of Stereolithography machine the generation of the supporters is

done automatically while preparing the 3-D CAD models. However, the

supports are removed manually when the product is ready. In some of the

rapid prototyping process, the supports are removed automatically.

Stereolithography is beneficial in all the fields. The biggest advantage of

this technology is that functional parts are created within no time and play a

vital role in the working environment. They are also used for various

purposes like thermoforming, blow molding, injection molding and provide

strong mechanisms. This technology is economical and can be implemented

in various sectors at affordable prices.



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Virtual Prototyping Virtual Prototyping is used to add a sense of contact and manipulation to the

CAD design of mechanical assemblies. Assembly, part interaction and

manipulability can then be evaluated without fabrication of physical

prototypes. With the industry leading virtual test of NI Lab VIEW, the

integration between capture and simulation provides exciting new

possibilities for design engineers powered by test and measurements. Such

possibility is called as virtual prototyping.

The virtual prototype is an important step in the iterative simulation process.

It acquires a real signal and introduces this data into a SPICE simulated

circuit. These combinations of a mathematical SPICE model of a circuit with

real stimuli are better in approximating the behavior of a circuit and

therefore improve the final product of the design stage. It is an advanced

approach to electronics design which makes use of signals that are gained

by means of a real-source and are saved to a measurement file. Then it is

incorporated into a SPICE simulation as the circuit stimuli.

Virtual prototyping makes it possible for an engineer to replicate a design on

the basis of an actual input stimuli and also helps him build a model that

approximates the behavior of a circuit in a better way. By using this method

a physical function generator or power, supply can be effectively plugged

into the SPICE simulation engine. In this way, it gives the engineer a

standard reference point to better understand the actual circuit performance.

To easily connect an arbitrary waveform generator, real-world function

generator or any other electrical source; the prototype lets an engineer

make use of the NI Lab VIEW programming language effectively. It helps

them by simulating the prototype during tests that deal with validation and

verification process. Such signals can be calculated and with all the real-


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world effects acquired (such as noise, phase and amplitude shifting etc…), it

can be saved to a Lab VIEW measurement file (.LVM) on a PC. These are all

elements of a signal, which cannot be effortlessly modeled by making use of

SPICE alone.

The data can be easily used throughout the design process, as contained by

the integrated NI circuit design platform the LVM format is common to the

tool-chain. That is why acquired measurements can be very easily

introduced into NI Multisim and can be transformed into a source that can

readily drive a circuit.

With the help of virtual prototyping, an engineer benefits from a computer

simulation in Multisim that is driven by the identical inputs that will

ultimately power a prototype or final production circuit. That is why the

result of alternative signals upon a circuit’s performance can be immediately

determined. It is possible to see crosstalk, noises and EMI interference. Then

it is determined within the design stages by making use of NI Multisim.

We can effectively plug a physical source, noise and effects included, into a

Multisim simulation by acquiring a real signal with NI Lab VIEW, thereby

creating a virtual prototype. The modified designs, which associate with real

source effects, can be uncovered at the earliest stages of the design process

rather than during the prototype stages. Moreover, the cost of virtual

prototyping is less and less time is required to re-design the boards.

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