Prototyping Basics Vol. 2

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2 DISCLAIMER This information is provided "as is". The author, publishers and marketers of this information disclaim any loss or liability, either directly or indirectly as a consequence of applying the information presented herein, or in regard to the use and application of said information. No guarantee is given, either expressed or implied, in regard to the merchantability, accuracy, or acceptability of the information. Unauthorized duplication or distribution of this material in any form is strictly prohibited. Violators will be prosecuted to the fullest extent of the law. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission from the author/publisher. The author, publisher, and distributor, of this product assume no responsibility for the misuse of this product, or for any injury, damage and/or financial loss sustained to persons or property as a result of using this book. While every effort has been made to ensure reliability of the information within, the liability, negligence or otherwise, or from any use, misuse, or abuse of the operation of any methods, strategies, instructions or ideas contained in the material herein is the sole responsibility of the reader. Page 2

3 Table of Contents DISCLAIMER... 2 History of Rapid Prototyping... 5 Inventions and Prototypes... 7 Injection Molding Prototyping D printers D printing technology D scanning and Prototyping Additive fabrication Advantages of rapid prototyping Casting Prototype Designing and Prototyping Disadvantages of Rapid Prototyping DIY Rapid Prototyping - Home Made 3D Printer Electron Beam Melting Fused Deposition Modeling Laminated Object Manufacturing Prototyping vs. rapid prototyping Rapid manufacturing Rapid Prototyping Rapid Prototyping Overseas Rapid prototyping services Rapid Prototyping Technologies Reverse engineering Page 3

4 Selective laser sintering Stereolithography Virtual Prototyping Page 4

5 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 threedimensional 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 Page 5

6 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. Page 6

7 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 nonworking models to 3D virtual designs showing functionality. Page 7

8 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. Page 8

9 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. Page 9

10 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 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. Page 10

11 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. Page 11

12 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. Page 12

13 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 Page 13

14 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. Page 14

15 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 Page 15

16 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 timeconsuming 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. Page 16

17 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. Page 17

18 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. Page 18

19 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 Page 19

20 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. Page 20

21 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. Page 21

22 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. Page 22

23 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 lowfidelity 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 highfidelity 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 Page 23

24 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. Page 24

25 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. Page 25

26 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 26

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. Page 27

28 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 28

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. Page 29

30 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 30

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. Page 31

32 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 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 32

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. Page 33

34 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 34

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 35