An introduction to cad
Download as DOCX, PDF1 like245 views
An introduction to CAD systems is presented. CAD packages are tools used to automate drafting, designing, and engineering processes across many industries. They have been commercially used for over 20 years to produce drawings like electrical, mechanical, civil, and more. CAD systems allow linking with other automation packages. Components of a CAD system include the software program for drawing/modifying and the hardware like workstations, plotters, and servers. The software provides tools for drawing, modifying, adding dimensions, and sending/plotting drawings. The hardware includes PCs, monitors, and plotters. Plotters receive drawing information as vectors or raster images and can use various pens/tools.
![If not checked properly, the object created can go very wrong
Can be very expensive Can be hard to do and handling needs training
Since not manual, can be slightly irritating becauseif not familiar with technology,
it is very hard to insure exactly what is wanted by the designer e.g. If wanted
something engraved instead of cut, the line colour has to be changed into blue in
stead of red. Sometimes you can't do everything you want to becausethe tools
aren't available Lots of people lost their jobs when CAD CAM originally came out
CAD disadvantages include: 1: Difficulty keeping track of changes when many
people are working on drawings for a project (Revision Control).
2: Protecting your ideas is difficult when you must share your drawings with
customers and contractors, but you need input about design questions (Intellectual
Property). 3: Sharing your drawings with other companies who may not be using
the same CAD programs.
CAM disadvantages include 1: Potential for wasted parts and materials due to
inaccurate CAD. 2: Machinery can break down, halting production. 3: Initial setup
of the productionline can be expensive, making limited runs cost-prohibitive.
CAM Advantage: Very fast setup of machinery for large volume productionruns...
More Specific Definitions
• Computer-Aided Design (CAD) is the technology concerned with the use of
computer systems to assist in the creation, modification, analysis, and optimization
of adesign. [Groover and Zimmers, 1984]
• Computer-Aided Manufacturing (CAM) is the technology concerned with the use
of computer systems to plan,manage, and control manufacturing operations.
• Computer-Aided Engineering (CAE) is the technologyconcerned with the use of
computer systems to analyzeCAD geometry, allowing the designer to simulate
andstudy how the productwill behave.
Introduction plotter machine
A plotter is a very versatile tool. It is sometimes confused with a printer, but a
plotter uses line drawings to form an image instead of using dots. A common type
of plotter is one that uses a pen or pencil, usually held by a mechanical “arm,” to
draw lines on paper as images are typed. It may be a componentthat is added to a](https://image.slidesharecdn.com/anintroductiontocad-161124143133/85/An-introduction-to-cad-26-320.jpg)
An introduction to cad
- 1. An introduction to CAD Introduction: distribution systemautomation is built on5pillars which are computerprogramming,computer aided design &drafting (CADD), systemsupervisory&dataacquisition systems (SCADA),localnetworks including LAN &WANand geographic information systems(GIS) including globalpositioning system(GPS)software& receivers. In this article anintroduction to CADsystemswill bepresented.TheCADpackagesare thetoolsusedtoautomate the drafting/designing/engineeringprocesses in almostall industries &technical operations.The CADprogramwas 1ofthefirst toolstobeusedtoautomate the technical officesofany organization. SuchCADpackageshave beenin use(commercially) forover20years in consulting firms, industrial plants, refineries, petrochemical plants,utilities andothersectorsof theindustry. Theyproducedrawings ofevery type:electrical, mechanical,civil, architecture, process, instrumentation,....etc. Depending ontheuserfield ofinterest, the CADsystemcantie in with otherautomating/analysis/production packages,forexample CAM (computeraided manufacturing) &GIS(Geographic information systems).Overthe recentfew years alot ofdevelopment tookplacewith respecttoCADsystems.Theinterface between the userand softwareisbecoming easier &similar tootheroff-the-shelf general softwarepackages.The drawings canbecheckedagainst specified standards.Thedrawings canbesentovertheinternet forviewing ormarking& checking. Theattributes (fields) ofthe drawnobjects(entities) canbe accessedviaother non-CADsoftwarepackages.Thedrawing canbefed into anotherprogram foranalysis ordisplaying detailedinformation.
- 2. Components of a CAD system: they canbeclassified broadlyinto the softwareandthe hardware. Thesoftwarebeing the programthat theuserwill interact with todraw, modify, store&plothis/her work.The hardware contains the workstations (orpersonalcomputers),theplotter&the server (fornetworked systems). The software: it providesthe userwith all the necessarytoolstodraw/sketch, modify, adddimensions,cross hatch, send&plothis/her drawing. Thesetoolsaredisplayed onthemonitor's screen. Theprogramwill allow morethan 1approachforentering the commandsorperforming the requiredfunctions. Thescreenmay bedivided into thefollowing sections:menu bar(or sometimes called pull-down menus), standardtoolbar,ribbonbar(orobjectpropertiestoolbar), drawing window with cursor,draw(quick)toolbar,modify toolbar,coordinatesystemicon, model& layout tab,commandwindowwith command line, statusline with toggle buttonsand feature (history) tree. Ingeneral, when atoolbariconis clicked 1of3actionswill take place:a dialog boxwill bedisplayed, afunction (sub-tool)barwill bedisplayed having additional functions that relate tothe clicked toolbariconoraspecific actionoccurs.
- 3. The hardware: Thepersonalcomputerwill beaPentium orcompatible microprocessorwithadequateamount ofRAM(64 MB ormorepreferred), compatible operating system,SVGA(orVGA) monitorcard, harddrive with sufficient space(capacity)toinstall thesoftwarepackage,mouse, parallelcommunication port,serialcommunication portand modemtoconnecttothe Internet. Theplotterconnectedtothenetwork canbeclassified into either vectororrasterdevices.The first receives theinformation (to beplotted)sentbyCADprograms(as vectors(lines basedon mathematical coordinate What is CAM? Complementary and alternative medicine (CAM) is a term used to describe a wide range of healing systems that are not considered part of mainstream or conventional Western medicine. The goal of conventional medicine is to find the physical sourceof a particular disease and then treat it. For example, if a person has an infection, a conventional doctormay prescribe an antibiotic to kill the invading bacteria. CAM practitioners, on the other hand, take a more "holistic" approachto health care. They believe that health and disease involve a complex interaction of physical, spiritual, mental, emotional, genetic, environmental, and social factors. In order to treat a disease or promotegood health, CAM
- 4. practitioners treat the whole person. In the United States, this holistic approach to health has been labeled "alternative" for a variety of reasons. Sometimes it is difficult to scientifically test alternative therapies in the same way that prescription drugs are tested. The conventional medical community relies on scientific evidence when evaluating the safety and effectiveness of a particular therapy. And while researchers are now beginning to test CAM therapies, scientific studies have long been focused on conventional treatments, meaning there is more evidence as to whether they work or not. In addition, many non-Western healing practices are not taught in United States medical schools, available to patients in U.S. hospitals, or covered by health insurance. What does complementary medicine and alternative medicine mean? The terms "complementary medicine" and "alternative medicine" are sometimes used to mean the same thing, but they have different implications. Complementary medicine refers to therapies used in combination with conventional medicine, while alternative medicine is used in place of conventional medicine. An example of complementary medicine is using hypnotherapy (hypnosis) with pain medications to reduce anxiety and enhance relaxation in people recovering from severe burns. An example of alternative medicine would be following a special diet and taking herbs or vitamins rather than medications to treat attention-deficit hyperactivity disorder (ADHD).
- 5. What is integrative medicine? The term "integrative medicine" is often used interchangeably with CAM, but it has a different meaning. Health care professionals who practice integrative medicine blend CAM therapies with mainstream medicine, rather than simply adding one complementary therapy (such as herbs) to a standard medical treatment. Forexample, an integrative treatment for Alzheimer's disease may include a combination of the following: Prescription medications that increase certain brain chemicals Antioxidants (such as vitamin E and ginkgo biloba ) Changes in lifestyle (such as walking programs and relaxation training) to reduce anxiety and improve behavior Music therapy More and more Americans are becoming familiar with integrative medicine. Studies have found that this blended approachto health care is safe and effective for a growing number of medical conditions. What are the basic principles of CAM? Although CAM therapies vary widely, several themes can be traced through them all: The focus is on the whole person -- physical, emotional, social, and spiritual. Prevention of illness is a primary concern. Treatments are highly individualized. Treatments are aimed at the causes of illness rather than at its symptoms. Treatments are designed to supportthe natural healing processesofthe body.
- 6. Who is using CAM? The healing practices are increasingly being tested for effectiveness and safety in well-designed research studies. Once distant healing practices are becoming more common, and more Americans are turning to integrative medical care than ever before. The movement toward integrative medicine in the United States has been prompted by a growing consumer demand for CAM services. A survey given to more than 31,000 U.S. adults found that nearly 70% of Americans have used at least one form of CAM therapy in their lifetime, making this "unconventional" medical approach one of the fastest growing sectors ofAmerican health care. In 2004 in the United States, 36% of adults were using some form of CAM. When megavitamin therapy and prayer specifically for health reasons were included in the definition of CAM, that number rose to 62%. The survey also found that CAM approaches are most often used to treat back pain or problems, colds, neck pain or problems, joint pain or stiffness, and anxiety or depression. However, only about 12% of adults sought care from a licensed CAM practitioner, suggesting that most people who use CAM do so on their own.
- 7. According to the survey, the 10 most commonly used CAM therapies and the percent of U.S. adults using each therapy were: Prayer for own health, 43% Prayer by others for the respondent's health, 24% Natural products (suchas herbs, other botanicals, and enzymes), 19% Deep breathing exercises, 12% Participation in prayer group for own health, 10% Meditation, 8% Chiropractic care, 8% Yoga, 5% Massage, 5% Diet-based therapies (such as Atkins, Pritikin, Ornish, and Zone diets), 4% The survey also found information about why people use CAM: 55% of adults said they believed that it would help them when combined with conventional medical treatments. 50% thought CAM would be interesting to try. 26% used CAM because a conventional medical professional suggested they try it. 13% used CAM because they felt that conventional medicine was too expensive. Studies also report 41% of people who use CAM use two or more CAM therapies during the prior year. The highest rates of CAM use tend to be among people ages 40 - 64, females, non-black/non-Hispanic, and with annual income of $65,000 or Although herbs and supplements are not regulated by the U.S. Food and Drug Administration, pharmacies across the country are seeing a surge in the demand for these alternative remedies. Pharmacists are being trained to counselpeople on the
- 8. safe and efficient use of CAM therapies. Most U.S. medical schools also now include instruction about CAM. More and more health insurance plans are also covering CAM, particularly treatments such as acupuncture and chiropractic, whose safety and effectiveness for treating certain health problems has been well researched. A study found that among the 600,000 enrollees in a particular health insurance plan, 13.7% made CAM claims. Of those, 1.3% made claims for acupuncture, compared with 1.6% for naturopathic medicine, 2.4% for massage, and 10.9% for chiropractic. What are the major types of CAM? The National Center for Complementary and Alternative Medicine (NCCAM) classifies CAM therapies into 5 major groups: Alternative medical systems: built upon complete systems of theory and practice. Examples include homeopathy, naturopathy, traditional Chinese medicine (TCM), and Ayurveda. Biologicalmedicine: use of substances found in nature, such as herbs, foods, and vitamins to promote health. Energy medicine: involves the use of energy fields to promote health. Some kinds of energy medicine (known as biofield therapies) aim to influence energy fields believed to surround and penetrate the human body. Examples include qi gong, Reiki, and Therapeutic Touch. Other forms of energy medicine (known as bioelectromagnetic-based medicine) use electromagnetic fields, such as electroacupuncture. Manual medicine: based on manipulation and movement of one or more parts of the body. Examples include osteopathy, physical therapy, massage, chiropractic, Feldenkrais, and reflexology.
- 9. Mind-body medicine: uses a range of techniques that help boostthe mind's ability to influence bodily functions. Examples include biofeedback, deep relaxation, guided imagery, hypnotherapy, meditation, prayer, support groups, and yoga. What types of changes in policy are happening in order to incorporate CAM into the U.S. medical system? In 1991, under a Congressional mandate, the National Institutes of Health (NIH) established the Office of Alternative Medicine (OAM). OAM was to evaluate CAM practices, supportCAM research and training, and establish a CAM information clearinghouse for the public. In 1998 Congress established the National Center for Complementary and Alternative Medicine (NCCAM) to take the place of the OAM. NCCAM's mission is to supportCAM research and provide information to healthcare providers as well as the public. Among other efforts, NCCAM focuses on research that looks at the safety and effectiveness of herbs and nutritional supplements and how they might interact with medications. It also evaluates other CAM treatments such as acupuncture and chiropractic. NCCAM funds several research centers outside of the NIH. To learn more about the centers and their research agendas, visit NCCAM's web site at
- 10. What is the future of CAM? There are signs that CAM is becoming accepted into mainstream medicine. For example, breakthroughs in CAM research are now published in prestigious Western peer-reviewed journals such as the Journal of the American Medical Association and the Annals of Internal Medicine. Still, there are real obstacles to truly integrated medicine. Some of these obstacles include cultural issues, lack of scientific studies, and administrative problems. However, because conventional doctors and CAM practitioners bothwant to create safe, effective, and affordable treatments, the integration of the best CAM into conventional medicine may not be worlds away. Plotter A plotter is a very versatile tool. It is sometimes confused with a printer, but a plotter uses line drawings to form an image instead of using dots. A common type of plotter is one that uses a pen or pencil, usually held by a mechanical “arm,” to draw lines on paper as images are typed. It may be a componentthat is added to a computer system or it may have its own internal computer. It can be used to create layouts, diagrams, specs, and banners. A plotter may use multiple pens and pencils, which can be easily be changed out in order to create drawings of a different color or drawings that contain more than one
- 11. color. A plotter is preferred over a printer in many commercial applications, including engineering, becauseit is far more exact. Another type of plotter provides the ability to remove pens or pencils and replace them with other tools. This type of plotter is frequently used for commercial sign making. A penknife may be substituted for writing instruments, while pressure sensitive vinyl is frequently substituted for paper. As the sign maker types in letters, numbers, or symbols, the plotter cuts them from vinyl to create lettering for signs, billboards, vehicles, and many other applications. A plotter can generally cut both very tiny and very large images, cutting through the vinyl and leaving the paper backing intact, so the letters can easily be peeled away and applied to a surface. Cutting plotters Cutting plotter knives cut into a piece of material (paper, mylar or vinyl) that is lying on the flat surface area of the plotter. It is achieved because the cutting plotter is connected to a computer, which is equipped with specialized cutting design or drawing computer software programs. Thosecomputer software programs are responsible for sending the necessary cutting dimensions or designs in order to command the cutting knife to producethe correct project cutting needs. In recent years the use of cutting plotters (generally called die-cut machines) has become popular with home enthusiasts of paper crafts such as cardmaking and scrapbooking. Such tools allow desired card shapes to be cut out very precisely, and repeated perfectly identically. As of 2012 the best known cutters are probably the Cricut range of machines by Provo Craft. Other manufacturers of personal
- 12. cutting machines include Black Cat, Boss Kut, Craftwell, Pazzles, Silhouette and Sizzix. Working process The pen plotters use one or multiple pens to plot the image on the paper. Their speed varies between 15 to 30 inches per second of pen lines. The wholeimage to be plotted is controlled by various instructions used by the computer as a series in one of the plotter control language. Itis a single pen plotter and drawing contains only one color then the plotting is fastest. The pen draws the image according to the instructions received fromthe computer. But if it is a multicolor drawing then one needs to sit there and change the pens as and when required or prompted. This decreases the speed of plotting and also one has to sit there and watch the job continuousely. On the other hand in case of a multipen plotter the pens are changed automatically by the main pen holder fromthe pen assembly. The main pen holder collects the pens fromassembly as and when required and it acts on the instructions supplied by the computer. In mostof the cases the plotter starts with one pen and draws all portions of drawing of that color then changes the second pen complets the portion of that color. The process continues till all parts with all color of drawing is completed. Because the pen is changed automatically so it is faster than single pen plotter in case of multicolor drawing but it needs an ink that must dry quickly enough so that lines are not subsequently smeared by the pen
- 13. tip and also ink should not dry on the pen tip. Also all the pens filled with inks must be ready to starts the plotting. Some electrostatic plotters are also available which are morefaster than these plotters but they are very costly. Their working principle is similar to that of laser printer. They create the whole image to be plotted in their memory firstand it is plotted as a series of dots. They are used for continuous outputs and a paper roll is used formthen. How ever you can usecut sheets papers too, someother types of plotters are thermal plotter , laser plotter and Pencil plotter. The plotter are serial devices so they need serial ports for interfacing. Almostall plotters usethe 25 pin D shell connectors for their interfacing. The 25 wired cable uses one 25 DM and one 25 DF connector at its ends. The female connector is attached to the computer and the male connector is attached to the plotter. Manual vs CAD/CAM system in garment industry range of customer. With this flexible CAD System and plotte,r Unit C is able to reduce 50% of sample making time compared to Unit M. Productivity: As mentioned in the experimental procedure, the CAD/CAM System has a production of 15,856 pieces/day whereas the MANUAL system has 4,013 pieces/day.
- 14. • As the CAD/CAM process requires transfer of information or data for marker planning via floppy, the process is simplified and the production is increased. • In CAD/CAM system, the capacity of the cutting room has to deal with a mixture of different types of cloth. Whereas in MANUAL system it is highly impossible to work with mixture of different types of cloth. • With such a flexible cutting room facilities available, Unit C must have higher production rates compared with Unit M member together with very high cutting speed. Lead time for production: Lead-time of garment production is the number of days required to finish a garment from sample stage to finished garment. Lead-time of Unit C is about 39 days and of Unit M is around 55 days. Due to faster sample production, highly saved time and higher productivity combined with flexibility, CAD system Unit C is more acceptable. Conclusion Unit C is using CAD/CAM system for garment manufacturing. There is a significant improvement in productivity, and quality, leading to time reduction. The following are the some of the benefits of CAD/CAM that the author observed from the Unit C. • Reduction in pattern designing, grading, and pattern alteration time by around 90%. The time required for Unit C is 36.81 minutes and for line M is about 350 minutes. • Greater flexibility in pattern designing, grading and marking • Reduction in waste% of up to 10%. • Increasing quality of cutting room by around 50%. • Reduction in sample making time by 60%. Unit C ---- 5 days Unit M ---- 10 days • Increasing monthly productivity by 75%. Productivity/day (Unit C) -15,856
- 15. Productivity/day (Unit M) - 4,013 • Reduction in lead-time up to 45 days. Unit C ----- 39 days Unit M ---- 55 days References 1. www.lectra.com. 2. www.tukatech.com. 3. www.fashionflame.com. 4. www.gerber.com. 5. Gerry C: Introduction to Clothing Manufacture, Blackwell Science (London) 1991. 6. Pooja Gupta: Evolution of Design Solutions in the Textile and Apparel Industry, Clothesline, Vol 14. Note: For detailed version of this article please refer the print version of The Indian Textile Journal February 2010 issue. V Parthasarathi Department of Fashion Technology PSG College of Technology, Coimbatore 641 004. Email: sarathi_vp@hotmail.com. Advantages of CAD software The previous section of this article identified several scenarios that might indicate that it is time to invest in a new CAD software system; here we explain how CAD software can address thoseissues and offer insight into additional advantages of CAD software. We also introduce the conceptof Building Information Modeling, which extends CAD beyond a project's design phase to construction, operation and maintenance. One of the most obvious advantages of CAD software is the use of digital models instead of paper blueprints. Here measurements are automatic, and lines, shapes and objects can be created with simple mouse clicks as opposed to slide rulers and calculators. Models can also be viewed in three dimensions. Another advantage of CAD software is data centralization. All digital blueprints are saved on the same server, not in disparate file cabinets, and can be accessed by anyone who uses the software. (Some CAD software also gives users the chance to view files on mobile devices.) This lets designers in different locations work on the
- 16. same project, sharing edits and modifications, which reduces communication bottlenecks and improves efficiency, accountability and project execution. Finally, many CAD software tools integrate with costestimating software or, at the very least, let users export information such as lists of building components (windows, doors, pieces of furniture, etc.) This, too, saves time and reduces the likelihood of transcription errors, since part lists need not be recreated. Benefits of the CAD Software CAD software is being used on large scale basis by a number of engineering professionals and firms for various applications. The most common application of CAD software is designing and drafting. Here are some of the benefits of implementing CAD systems in the companies: 1) Increase in the productivity of the designer: The CAD software helps designer in visualizing the final productthat is to be made, it subassemblies and the constituent parts. The productcan also be given animation and see how the actual productwill work, thus helping the designer to immediately make the modifications if required. CAD software helps designer in synthesizing, analyzing, and documenting the design. All these factors help in drastically improving the productivity of the designer that translates into fast designing, lower designing costand shorter project completion times. 2) Improve the quality of the design: With the CAD software the designing professionals are offered large number of tools that help in carrying out thorough engineering analysis of the proposed design. The tools also help designers to consider large number of investigations. Since the CAD systems offer greater accuracy, the errors are reduced drastically in the designed productleading to better design. Eventually, better design helps carrying out manufacturing faster and reducing the wastages that could have occurred because of the faulty design. 3) Better communications: The next important part after designing is making the drawings. With CAD software better and standardized drawings can be made easily. The CAD software helps in better documentation of the design, fewer drawing errors, and greater legibility.
- 17. 4) Creating documentation of the designing: Creating the documentation of designing is one of the most important parts of designing and this can be made very conveniently by the CAD software. The documentation of designing includes geometries and dimensions of the product, its subassemblies and its components, material specifications for the components, bill of materials for the components etc. 5) Creating the database for manufacturing: When the creating the data for the documentation of the designing most of the data for manufacturing is also created like products and componentdrawings, material required for the components, their dimensions, shape etc. 6) Saving of design data and drawings: All the data used for designing can easily be saved and used for the future reference, thus certain components don’thave to be designed again and again. Similarly, the drawings can also be saved and any number of copies can be printed whenever required. Some of the component drawings can be standardized and be used whenever required in any future drawings. Disadvantages: One of the biggest disadvantages is the loss of several hours worth of work. This can happen anytime you don'tsave your work often, if it gets erased, or if a large network goes offline. Something else that could be a disadvantage would be the fact that you can only use CAD software effectively and efficiently if you ha ve taken classes or read instructional books, bothof which take time and money. The only other disadvantage, is that an architect or engineer can draw anything on paper that someone can draw on a computer, this last is not much of a disadvantage because of how much faster blueprints can be created and rendered with CAD software If computer problem, all data will be lost If not checked properly, the object created can go very wrong Can be very expensive Can be hard to do and handling needs training Since not manual, can be slightly irritating becauseif not familiar with technology,
- 18. it is very hard to insure exactly what is wanted by the designer e.g. If wanted something engraved instead of cut, the line colour has to be changed into blue instead of red. Sometimes you can't do everything you want to because the tools aren't available Lots of people lost their jobs when CAD CAM originally came out CAD disadvantages include: 1: Difficulty keeping track of changes when many people are working on drawings for a project (Revision Control). 2: Protecting your ideas is difficult when you must share your drawings with customers and contractors, but you need input about design questions . 3: Sharing your drawings with other companies who may not be using the same CAD programs. CAM disadvantages include 1: Potential for wasted parts and materials due to inaccurate CAD. 2: Machinery can break down, halting production. 3: Initial setup of the productionline can be expensive, making limited runs cost-prohibitive. CAM Advantage: Very fast setup of machinery for large volume productionruns... CAD/CAM for Students CAD/CAM Books: following are some of the world known books on CAD/CAM. These books will help in understanding the basic concepts ofCAD/CAM technology. These books will upgrade your thinking from a mechanical engineer to CAD/CAM engoineer. you can purchase these bookonline and from the bookstores. CADCAM: Principles, Practice and Manufacturing Management(2nd Edition) (Hardcover)
- 19. The optimum path to become a CAD/CAM Engineer is to seek the best on hand training. Upon getting Diploma, Degree in engineering, students are encouraged to go through a short term (One year/Six months) coursewith a concentration in CAD/CAM technology. Graduates can then seek direct employment experience in the field or go on to pursue a further degree at a senior institution. Many employers pay part of the expense for college level courses aimed at an employee’s continued development. CAD/CAM Learning CAD (computer aided designing) is assistance of computer in Design process. This technology is being used in almost every field of engineering suchas Mechanical, Civil, Architecture, Automobile, Aerospace, Electrical; Electronics etc. these all branches have their different softwares. CAM (Computer aided Manufacturing) is assistance of computer in Manufacturing process. Different engineering branches are having their own manufacturing/production processes. Thecomputer may have direct interface such as CNC, DNC etc. and indirect interface such as inspection, process planning and documentation where computers are used. Students can learn CAD software related to their own field. These softwares are having different levels form high capability and low capability. It is recommended that student should learn high end software He will be able to handle most of the
- 20. CAD tasks such as modeling, assemblage, analysis, drafting, tooldesign etc. After that he will be able to learn and handle most of the other softwares related to his field with minimum effort and training. Checklist before selecting institute to learn CAD/CAM 1. Industrialconnection of the institute providing CAD/CAMsoftwares. 2. Trainers of that institute should be having practical knowledgeabout CAD/CAMand some work experience also. 3. Instituteshould be certified by the companies providing CAD/CAM softwares and trainings. 4. Check the contents of the courses. Itshould be including both CAD and CAM modules. 5. Check the placement assistanceinstitute can provide. Try to find the previous placement record of that institute. 6. Find the teaching methodology. Itshould be on the concept of projectwork by students and not only lecture based. 7. Check the hardwaresupportof that institute. Instituteshould have high configuration computer fromreputed companies. 8. Check the links of that institute with industries for industrialexposure of that institute such as plastic, automobile, home appliance industries. 9. Check the softwarelist of that institute. Itshould have mostof the high end softwares. 10.Compare the fees structurewith the contents. Itshould be according to the contents of the course. Don’tlook at cheaper courses.
- 21. Introduction CAD software Introduction CAD software: Computer Aided Design (CAD) is a form of design in which people work with computers to create ideas, models, and prototypes. CAD was originally developed to assist people with technical drawing and drafting, but it has expanded to include numerous other potential uses. A variety of software products designed for CAD can be found on the market, with many being targeted to a specific application or industry. Drafting and technical drawing can be very painstaking, and they require some special skills. Using CAD for drafting still requires many of the same skills, but by working with a computer instead of on paper, people can be much more efficient. They can also play around with ideas much more easily, moving design elements around and running the design through software programs which can determine whether or not the design is structurally viable. For example, an architect working on a bridge can test the design in simulations to see if it will withstand the load it will need to carry. CAD can be used to design structures, mechanical components, and molecules, among other things. One advantage of using CAD is that people don't have to make prototypes to demonstrate a project and its potential, as they can use a three dimensional modeling program to show people how something might look. CAD also allows for endless variations and experiments to show how the look and feel of something can be altered, and these can be done at the click of a button, rather than with painstaking drafting work. Advanced CAD programs usually require extensive training from their users, as they can be very complex and challenging to work with. More casual programs can be learned in shorter periods of time, with some designed to allow people to work within the program immediately, learning as they go. Simple programs can also sometimes have their functionality increased with expansion packs which are designed to provide additional features, so that people can work within a program they are familiar with when they want to develop more complex designs.
- 22. Different CAD Software Name: There are multiple CAD programs available for design. Generally people become familiar with one and stick with it. As far as selecting the right one, my advice is this. Most software companies have a free trial. Thirty-day trials are common. Take advantage of these trial periods and test the software out. Then at the end, decide if you want to try software or stick with your best one. I would advise you try out at least three different packages. The one you select will probably have to do with you liking the interface or finding it intuitive. Keep in mind it may work for you now. A simple to use and understand interface probably has some limitations for your designs. The very bestprograms are complex with many tools that give you the most control. I have found that I start with a simple program and outgrow it. At some point I move up to the next level of software. This usually means a higher price as well. Types of CAD There are different types of CAD out there. These are the ones I deal with from time to time. 2D CAD, 2.5D CAD, and 3D CAD. Here are some quick explanations of each type. 2D CAD 2D CAD is generally on the low end of CAD software packages. 2D CAD is most often vector based. The design consists on the X and Y-axis only. The designs are made up of lines, circles, ovals, slots, curves, etc. There is no "depth" to the design. Only the outline of the part is visible, to put it in a different way. 2.5D CAD All of the same descriptions above apply, but the design is prismatic. By that I mean it has the depth of the material. There are Z levels, but they are on singular planes. 3D CAD 3D CAD is on the high end of CAD software packages. 3D CAD can be solid based, wire frame based or nubs based. The design consists on the X, Y and Z-axis. The designs are made up of lines, circles, ovals, slots, curves, etc, but can also
- 23. include Spheres, Pyramids, Torrid, Cubes, etc. There is depth to the design. The design can be rotated around 360 degrees. The design is an accurate description of what the part would look like if produced in the real world. Some software packages provide the ability to edit parametric and non-parametric geometry without the need to understand or undo the design intent history of the geometry by use of direct modeling functionality. This ability may also include the additional ability to infer the correct relationships between selected geometry (e.g., tangency, concentricity) which makes the editing process less time and labor intensive while still freeing the engineer from the burden of understanding the model’s. These kind of non-history based systems are called Explicit Modellers or Direct CAD Modelers. Need for CAD/CAM • To increase productivity of the designer • To improve quality of the design • To improve communications • To create a manufacturing database • To create and test toolpaths and optimize them • To help in production scheduling and MRP models • To have effective shop floor control
- 24. Objectives • To understand the need for CAD/CAM in Lean Manufacturing. • To be able to create 2D Geometries in MASTERCAM • To be able to create 2D toolpaths in MASTERCAM • To use MASTERCAM for identifying optimum toolpaths • To generate NC codes using MASTERCAM Benefits of the CAD Software Use: • CAD software is being used on large scale basis by a number of engineering professionals and firms for various applications. The most common application of CAD software is designing and drafting. Here are some of the benefits of implementing CAD systems in the companies: 1) Increase in the productivity of the designer: • The CAD software helps designer in visualizing the final productthat is to be made, it subassemblies and the constituent parts. The productcan also be given animation and see how the actual productwill work, thus helping the designer to immediately make the modifications if required. CAD software helps designer in synthesizing, analyzing, and documenting the design. All these factors help in drastically improving the productivity of the designer that translates into fast designing, lower designing costand shorter project completion times. 2) Improve the quality of the design: With the CAD software the designing professionals are offered large number of tools that help in carrying out thorough engineering analysis of the proposed design. The tools also help designers to consider large number of investigations. Since the CAD systems offer greater accuracy, the errors are reduced drastically in the designed productleading to better design. Eventually, better design helps carrying out manufacturing faster and reducing the wastages that could have occurred because of the faulty design.
- 25. 3) Better communications: The next important part after designing is making the drawings. With CAD software better and standardized drawings can be made easily. The CAD software helps in better documentation of the design, fewer drawing errors, and greater legibility. 4) Creating documentation of the designing: Creating the documentation of designing is one of the most important parts of designing and this can be made very conveniently by the CAD software. The documentation of designing includes geometries and dimensions of the product, its subassemblies and its components, material specifications for the components, bill of materials for the components etc. 5) Creating the database for manufacturing: When the creating the data for the documentation of the designing most of the data for manufacturing is also created like products and component drawings, material required for the components, their dimensions, shape etc. 6) Saving of design data and drawings: All the data used for designing can easily be saved and used for the future reference, thus certain components don’thave to be designed again and again. Similarly, the drawings can also be saved and any number of copies can be printed whenever required. Some of the component drawings can be standardized and be used whenever required in any future drawings. Disadvantages: One of the biggest disadvantages is the loss of several hours worth of work. This can happen anytime you don'tsave your work often, if it gets erased, or if a large network goes offline. Something else that could be a disadvantage would be the fact that you can only use CAD software effectively and efficiently if you ha ve taken classes or read instructional books, bothof which take time and money. The only other disadvantage, is that an architect or engineer can draw anything on paper that someone can draw on a computer, this last is not much of a disadvantage because of how much faster blueprints can be created and rendered with CAD software If computer problem, all data will be lost
- 26. If not checked properly, the object created can go very wrong Can be very expensive Can be hard to do and handling needs training Since not manual, can be slightly irritating becauseif not familiar with technology, it is very hard to insure exactly what is wanted by the designer e.g. If wanted something engraved instead of cut, the line colour has to be changed into blue in stead of red. Sometimes you can't do everything you want to becausethe tools aren't available Lots of people lost their jobs when CAD CAM originally came out CAD disadvantages include: 1: Difficulty keeping track of changes when many people are working on drawings for a project (Revision Control). 2: Protecting your ideas is difficult when you must share your drawings with customers and contractors, but you need input about design questions (Intellectual Property). 3: Sharing your drawings with other companies who may not be using the same CAD programs. CAM disadvantages include 1: Potential for wasted parts and materials due to inaccurate CAD. 2: Machinery can break down, halting production. 3: Initial setup of the productionline can be expensive, making limited runs cost-prohibitive. CAM Advantage: Very fast setup of machinery for large volume productionruns... More Specific Definitions • Computer-Aided Design (CAD) is the technology concerned with the use of computer systems to assist in the creation, modification, analysis, and optimization of adesign. [Groover and Zimmers, 1984] • Computer-Aided Manufacturing (CAM) is the technology concerned with the use of computer systems to plan,manage, and control manufacturing operations. • Computer-Aided Engineering (CAE) is the technologyconcerned with the use of computer systems to analyzeCAD geometry, allowing the designer to simulate andstudy how the productwill behave. Introduction plotter machine A plotter is a very versatile tool. It is sometimes confused with a printer, but a plotter uses line drawings to form an image instead of using dots. A common type of plotter is one that uses a pen or pencil, usually held by a mechanical “arm,” to draw lines on paper as images are typed. It may be a componentthat is added to a
- 27. computer system or it may have its own internal computer. It can be used to create layouts, diagrams, specs, and banners. A plotter may use multiple pens and pencils, which can be easily be changed out in order to create drawings of a different color or drawings that contain more than one color. A plotter is preferred over a printer in many commercial applications, including engineering, becauseit is far more exact. Another type of plotter provides the ability to remove pens or pencils and replace them with other tools. This type of plotter is frequently used for commercial sign making. A penknife may be substituted for writing instruments, while pressure sensitive vinyl is frequently substituted for paper. As the sign maker types in letters, numbers, or symbols, the plotter cuts them from vinyl to create lettering for signs, billboards, vehicles, and many other applications. A plotter can generally cut both very tiny and very large images, cutting through the vinyl and leaving the paper backing intact, so the letters can easily be peeled away and applied to a surface. PlotterMachine Cutting plotters Cutting plotter knives cut into a piece of material (paper, Mylar or vinyl) that is lying on the flat surface area of the plotter. It is achieved because the cutting plotter is connected to a computer, which is equipped with specialized cutting design or drawing computer software programs. Thosecomputer software
- 28. programs are responsible for sending the necessary cutting dimensions or designs in order to command the cutting knife to producethe correct project cutting needs. In recent years the use of cutting plotters (generally called die-cut machines) has become popular with home enthusiasts of paper crafts such as card making and scrapbooking. Such tools allow desired card shapes to be cut out very precisely, and repeated perfectly identically. As of 2012the best known cutters are probably the Circuit range of machines by Provo Craft. Other manufacturers of personal cutting machines include Black Cat, Boss Cut, Craft well, Puzzles, Silhouette and Size. Working process The pen plotters use one or multiple pens to plot the image on the paper. Their speed varies between 15 to 30 inches per second of pen lines. The whole image to be plotted is controlled by various instructions used by the computer as a series in one of the plotter controllanguage. It is a single pen plotter and drawing contains only one color then the plotting is fastest. The pen draws the image according to the instructions received from the computer. But if it is a multicolor drawing then one needs to sit there and change the pens as and when required or prompted. This decreases the speed of plotting and also one has to sit there and watch the job continuously. On the other hand in case of a multiple plotter the pens are changed automatically by the main pen holder from the pen assembly. The main pen holder collects the pens from assembly as and when required and it acts on the instructions supplied by the computer. In most of the cases the plotter starts with one pen and draws all portions of drawing of that color then changes the second pen completes the portion of that color. The process continues till all parts with all color of drawing is completed. Because the pen is changed automatically so it is faster than single pen plotter in caseof multicolor drawing but it needs an ink that must dry quickly enough so that lines are not subsequently smeared by the pen tip and also ink should not dry on the pen tip. Also all the pens filled with inks must be ready to starts the plotting. Some electrostatic plotters are also available which are faster than these plotters but they are very costly. Their working principle is similar to that of laser printer. They create the whole image to be plotted in their memory first and it is plotted as a series of dots. They are used for continuous outputs and a paper roll is used form then. However you can use cut sheets papers too, some
- 29. other types of plotters are thermal plotter, laser plotter and Pencil plotter. The plotter is serial devices so they need serial ports for interfacing. Almost all plotters use the 25 pin D shell connectors for their interfacing. The 25 wired cable uses one 25 DM and one 25 DF connectorat its ends. The female connector is attached to the computer and the male connectoris attached to the plotter. What is a Digitizer Board? An electrical device connected to a computer that sends very accurate X,Y coordinates to the computer using a pen stylus or mouse-like cursor. Place an object or pattern on the digitizing tablet, start the digitizing software, place the pen stylus or cursor where digitizing should begin, push the buttons on the pen or cursorto start digitizing and digitize the object, pattern, design. Digitizing tablet sizes range from 44x60in (110x150cm), 36x48in (90x120cm), 24x36in (60x90cm), 20x24in (50x60cm), 12x18in (30x45cm), and 12x12in (30x30cm). Standard accuracy is .01" (10/1000) but higher accuracies are available. Digitizing software is required to use the digitizing tablet. PlotterMachine Why use a Digitizer Board? Save time and money using a Digitizer Board to trace or digitize designs, patterns, outlines, points, graphs, maps, templates, blueprints, plans, anything.Place the item on the Digitizer Board, start the Logic digitizing software, digitize the item, save as a file for use in other software or machinery.
- 30. Digitizer Board