Understanding Your Interferometric Test Results by James Mulherin

At Optical Mechanics our mission is to provide professional quality optics to the research and amateur astronomy community. To that end, we produce our OMI Newtonian mirrors adhering to a rigorous quality control process. The result is consistently high optical quality. Each OMI mirror is delivered with an interferometric certification that conforms to industry standards for research-grade astronomical optics. With this technical article we hope you will gain a better understanding of the critical interferometric certification process, what your interferometric test results mean and why interferometry is so important to ensuring that your optic will perform to your expectations. Each OMI mirror must meet or exceed specific wavefront quality specifications before it leaves our facility. These specifications are presented in the form of Peak-to-Valley (P-V), Root-Mean-Square (RMS) wavefront error, and Strehl ratio. The following paragraphs describe how these quantities are measured and what they mean. Below we describe the high-points of the iterative figuring and testing process whereby your mirror surface is polished from a sphere to a paraboloid. During this figuring process we use common phase modulation tests such as the Ronchi and Foucault tests. Then we explain why the final interferometric certification is so important to assuring that the mirror actually meets our pass criterion for wavefront quality. As a point of interest, we describe the string test; a basic technique that is used to make a qualitative assessment of your interferogram, and we present some sample interferograms that demonstrate the appearance of the third order Seidel aberrations; spherical aberration, astigmatism and coma. Finally, we visually inspect our OMI mirrors for scratches and pits during each step of the fabrication process to ensure that the mirror's surface meets well defined cosmetic quality standards. We describe this surface quality standard and what it means. Interferometric Wavefront Quality Specifications In an interferometric test, the shape of the wavefront produced by the optic under test is determined by combining its wavefront with a highly accurate reference wavefront. Constructive and destructive interference between the combined wavefronts produces interference fringes. These interference fringes are analogous to contour lines on an elevation map and they represent deviations of the wavefront under test from the optimal shape. The interference fringes are captured using a CCD camera and image capture board and displayed on a computer monitor. Fringe analysis software then picks hundreds of points along the fringes over the entire wavefront to accurately quantify the deviations. The output of the fringe analysis software describes the quality of the optic under test by reporting its P-V, RMS wavefront error, and Strehl ratio. The Peak-to-Valley wavefront error is a measure of the distance from the highest to the lowest point on the test wavefront relative to the reference wavefront. According to Optical Shop Testing by Daniel Malacara; "The P-V error must be regarded with some skepticism because it is calculated from the worst two interferometric data points out of possible thousands. It might make the system under test appear worse than it really is." Note that a mirror with a true P-V wavefront error of .25 wave, as verified by interferometry, will in any case meet or exceed the RMS wavefront and Strehl ratio criterion described below. Because P-V uses two points without regard to location on the mirrors surface, two mirrors may have the same P-V error but will be very different in overall quality. The difference in quality will be evident in the RMS and Strehl values. As an example, two mirrors may have the same P-V value due to a zone on the mirrors surface. Both of the mirrors have a high zone. The first mirror has its high zone near the center while the second has its high zone near the edge. The first mirror will have better RMS and Strehl values because the surface area covered by the high zone will be smaller in the center than at the edge. To obtain the RMS wavefront error, a large number of interferometric data points are measured over the entire area of the test wavefront. As explained in Optical Shop Testing; "The RMS error is a statistic that is calculated from all of the measured data and gives a better indication of the overall system performance." Due to its statistical nature, professional optical shops consider the RMS wavefront error to be the most useful measure of optical quality. By common convention an optic with RMS wavefront error of 0.0712 wave or less is considered diffraction limited. The Strehl ratio is another statistical measure of optical performance calculated from the interferometric test data. The Strehl ratio is the ratio of intensity of an aberrated wavefront to an unaberrated wavefront. In other words, the use of the Strehl ratio is a fundamental description of the amount of intensity reduction due to wavefront errors. A common convention is to consider an optic with a Strehl ratio of 0.8 or higher to be diffraction limited. The Strehl ratio and RMS wavefront error are mathematically related. It can be shown that a Strehl ratio of 0.8 corresponds to an RMS wavefront error of 0.0714 wave or approximately 1/14 wave. Why Interferometry is Important During the figuring process, the surface of your mirror is polished from a sphere to a paraboloid using an iterative process of testing and polishing to achieve the desired results. During this process we interpret the appearance of fringes in the Ronchi test and shadows in the Foucault test. Once the optician feels that the optic will pass the scrutiny of the interferometer, this test is performed. Due to the qualitative nature of the Ronchi and Foucault tests, and to the subjectivity in their interpretation, it is not infrequent that the interferometer will reject a mirror, sending it back for touch-up polishing. The interferometer is the final impartial go/no-go point in the quality control chain. It is a completely objective and accurate assessment of the quality of the optic under test. Although it is possible to produce diffraction limited mirrors using methods such as the Ronchi and Foucault test, it is impossible to accurately verify and the quality of the entire wavefront to a fraction of a wave without interferometry. The Ronchi and Foucault tests are excellent evaluation tools during mirror fabrication as they show the general shape of the wavefront as well as localized and high frequency errors extremely well. These tests can show localized errors as small as 1/100 wave. This makes them indispensable tools during mirror figuring. However, unlike interferometry, they do not provide a means of accurately quantifying the whole wavefront because they only measure a few points. Interferometry on the other hand, is an extremely strict statistical analysis that assures the customer of a truly diffraction limited optic over its entire wavefront.

Update for IEC Standards Collection-2010-10(2)

http://www.findstandards.info http://www.int-bizdirectory.com/ http://www.int-bizdirectory.com/standards.htm Quote: Hench2004@sina.com ISO/IEC 19775-2 Ed. 2.0:2010 Information technology — Computer graphics and image processing — Extensible 3D (X3D) — Part 2: Scene access interface (SAI) IEC 62376 Ed. 1.0:2010 Maritime navigation and radiocommunication equipment and systems – Electronic chart system (ECS) – Operational and performance requirements, methods of testing and required test results IEC 60745-2-14 Consol. Ed. 2.2 (incl. am1+am2):2010 Hand-held motor-operated electric tools – Safety – Part 2-14: Particular requirements for planers IEC 60695-6-1 Consol. Ed. 2.1 (incl. am1):2010 Fire hazard testing – Part 6-1: Smoke obscuration – General guidance IEC 60335-2-25 Ed. 6.0:2010 Household and similar electrical appliances – Safety – Part 2-25: Particular requirements for microwave ovens, including combination microwave ovens Project IEC 62660-1 Ed. 1.0:2010 Secondary lithium-ion cells for the propulsion of electric road vehicles – Part 1: Performance testing Project IEC 62150-2 Ed. 2.0:2010 Fibre optic active components and devices – Test and measurement procedures –Part 2: ATM-PON transceivers Project IEC 62026-7 Ed. 1.0:2010 Low-voltage switchgear and controlgear – Controller-device interfaces (CDIs) – Part 7: CompoNet Project IEC 60252-2 Ed. 2.0:2010 AC motor capacitors – Part 2: Motor start capacitors Project IEC 61753-086-6 Ed. 1.0:2010 Fibre optic interconnecting devices and passive components – Performance standard – Part 086-6: Non-connectorised single-mode bidirectional 1 490 / 1 550 nm downstream and 1 310 nm upstream WWDM devices for category O – Uncontrolled environment Project IEC 61300-3-22 Ed. 2.0:2010 Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 3-22: Examinations and measurements – Ferrule compression force Project IEC 61300-2-6 Ed. 2.0:2010 Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 2-6: Tests – Tensile strength of coupling mechanism Project IEC 60684-3-283 Ed. 1.0:2010 Flexible Insulating Sleeving – Part 3: Specifications for individual types of sleeving – Sheet 283: Heat-shrinkable, polyolefin sleeving for bus-bar insulation Project IEC 62660-2 Ed. 1.0:2010 Secondary lithium-ion cells for the propulsion of electric road vehicles – Part 2: Reliability and abuse testing Project IEC 61753-087-2 Ed. 1.0:2010 Fibre optic interconnecting devices and passive components – Performance standard – Part 087-2: Non-connectorized single-mode bidirectional 1 310 nm upstream and 1 490 nm downstream WWDM devices for category C – Controlled environment ISO/IEC/TR 29125 Ed. 1.0:2010 Information technology – Telecommunications cabling requirements for remote powering of terminal equipment IEC 60825-2-am2 Ed. 3.0:2010 Amendment 2 – Safety of laser products – Part 2: Safety of optical fibre communication systems (OFCS) IEC 60601-2-52 Ed. 1.0:2010 Corrigendum 1 – Medical electrical equipment – Part 2-52: Particular requirements for the basic safety and essential performance of medical beds IEC 60312-2 Ed. 1.0:2010 Vacuum cleaners for household use – Part 2: Wet cleaning appliances – Methods of measuring the performance IEC 60312-1 Ed. 1.0:2010 Vacuum cleaners for household use – Part 1: Dry vacuum cleaners – Methods for measuring the performance IEC/TR 60269-5 Ed. 1.0:2010 Low-voltage fuses – Part 5: Guidance for the application of low-voltage fuses Project IEC 61853-1 Ed. 1.0:2010 Photovoltaic (PV) module performance testing and energy rating – Part 1: Irradiance and temperature performance measurements and power rating Project IEC 60747-7 Ed. 3.0:2010 Semiconductor devices – Discrete devices – Part 7: Bipolar transistors Project IEC 60747-15 Ed. 2.0:2010 Semiconductor devices – Discrete devices – Part 15: Isolated power semiconductor Project IEC 60601-2-46 Ed. 2.0:2010 Medical electrical equipment – Part 2-46: Particular requirements for the basic safety and essential performance of operating tables Project IEC 60502-4 Ed. 3.0:2010:2010 Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) – Part 4: Test requirements on accessories for cables with rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV) Project IEC 62148-2 Ed. 2.0:2010 Fibre optic active components and devices – Package and interface standards – Part 2: SFF 10-pin transceivers ISO/IEC 27001-HBK Ed. 1.0:2010 ISO/IEC 27001 for Small Businesses – Practical advice IEC 62475 Ed. 1.0:2010 High-current test techniques – Definitions and requirements for test currents Project IEC 61853-1 Ed. 1.0:2010 Photovoltaic (PV) module performance testing and energy rating – Part 1: Irradiance and temperature performance measurements and power rating Project IEC 60747-7 Ed. 3.0:2010 Semiconductor devices – Discrete devices – Part 7: Bipolar transistors Project IEC 60747-15 Ed. 2.0:2010 Semiconductor devices – Discrete devices – Part 15: Isolated power semiconductor Project IEC 60601-2-46 Ed. 2.0:2010 Medical electrical equipment – Part 2-46: Particular requirements for the basic safety and essential performance of operating tables Project IEC 60502-4 Ed. 3.0:2010 Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) – Part 4: Test requirements on accessories for cables with rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV) Project IEC 62148-2 Ed. 2.0:2010 Fibre optic active components and devices – Package and interface standards – Part 2: SFF 10-pin transceivers ISO/IEC 27001-HBK Ed. 1.0:2010 ISO/IEC 27001 for Small Businesses – Practical advice IEC 62475 Ed. 1.0:2010 High-current test techniques – Definitions and requirements for test currents IEC 60269-6 Ed. 1.0:2010 Low-voltage fuses – Part 6: Supplementary requirements for fuse-links for the protection of solar photovoltaic energy systems IEC 60252-1 Ed. 2.0:2010 AC motor capacitors – Part 1: General – Performance, testing and rating – Safety requirements – Guidance for installation and operation IEC 60060-1 Ed. 3.0:2010 High-voltage test techniques – Part 1: General definitions and test requirements IEC/TS 62257-7-1 Ed. 2.0:2010 Recommendations for small renewable energy and hybrid systems for rural electrification – Part 7-1: Generators – Photovoltaic generators IEC/PAS 62326-14 Ed. 1.0:2010 Printed boards – Part 14: Device embedded substrate – Terminology / reliability IEC 61347-2-12-am1 Ed. 1.0:2010 Amendment 1 – Lamp controlgear – Part 2-12: Particular requirements for d.c. or a.c. supplied electronic ballasts for discharge lamps (excluding fluorescent lamps) IEC 62374-1 Ed. 1.0:2010 Semiconductor devices – Part 1: Time-dependent dielectric breakdown (TDDB) test for inter-metal layers ISO/IEC 29199-2 Ed. 2.0:2010 Information technology — JPEG XR image coding system — Part 2: Image coding Project IEC 62642-2-5 Ed. 1.0:2010 Alarm systems – Intrusion and hold-up systems – Part 2-5: Intrusion detectors – Combined passive infrared / Ultrasonic detectors Project IEC 62642-2-4 Ed. 1.0:2010 Alarm systems – Intrusion and hold-up systems – Part 2-4: Intrusion detectors – Combined passive infrared / Microwave detectors Project IEC 62642-2-3 Ed. 1.0:2010 Alarm systems – Intrusion and hold-up systems – Part 2-3: Intrusion detectors Project IEC 62509 Ed. 1.0:2010 Battery charge controllers for photovoltaic systems – Performance and functioning Project IEC 62271-206 Ed. 1.0:2010 High-voltage switchgear and controlgear – Part 206: Voltage presence indicating http://www.int-bizdirectory.com/ http://www.int-bizdirectory.com/standards.htm http://www.findstandards.info Quote: Hench2004@sina.com

Most Helpful Customer Reviews

The back cover claims that this is "The definitive guide to draughting to the latest ISO Standards, incorporating BS 8888". I cannot agree. This book seems to be a partial revision of a school or undergraduate drawing textbook. The authors might have achieved their objective if they had started from scratch. As it is, it would be better to call it a Rough Guide. It will be useful to beginners, but it is certainly not "definitive". The description of CAD systems in chapter 3 is heavily biased towards AutoCad, even when describing 3D programmes, in which they have never been dominant. The screenshot examples shown, over five pages, are taken as much from architecture as engineering, and are poorly reproduced. Captions are minimal, and the relevance to engineering of a dragonfly flying over a pond is hard to see. Two potentially informative screenshots of drawings in progress seem to have been printed in soot. The clarity and sharpness of a screen image is entirely lost. The authors appear to have shares in Mechsoft and the inclusion of two pages of AutoCad publicity material do little to advance the subject. The space would have been better used to illustrate the working methods of CAD programmes, particularly showing the difference between 2D and 3D work, and explaining the significance of Surface and Solid modelling, leading on to Hybrid programmes. The further use of 3D models for stress, heat flow, or fluid dynamics could have been illustrated. After pointing out on page 6 that the comma is to be the decimal marker, it is odd that the majority of drawings shown use the full stop, or point. The diameter symbol shown in the text does not agree with that shown in some illustrations, but the use is inconsistent. In both cases the symbol is incorrect. The section on drawing nuts and bolts continues a method which has been a poor approximation for more than fifty years, but makes no mention of using stencils, or CAD libraries, which would give an accurate representation. Chapters 20 to 23 reproduce the symbols for geometrical tolerancing as provided by AutoCad, including the errors. It would have been better to show them proportioned correctly to the standard. Several examples seem to have abandoned the correct use of line thickness. Chapter 26 shows welding symbols to BS 499. The authors should be aware that this was superseded in 1995 by BS EN 22553. Some explanation of the previous ways of working may be needed, but the emphasis should be on the current standard. The engineering diagrams in chapter 27 give a small selection of symbols to current standards, but far more space is given over to poor or non standard examples. The symbols used are inconsistent and no account has been taken of Reference Designations as specified in BS EN 61346. The section on Heating and Ventilation diagrams drifts into design techniques, which would be better covered in a Design textbook. The chapter on bearings similarly becomes a design manual, but the one illustration of the representation of bearings on a drawing is badly printed and incorrect. To add insult to injury, the text states that the drawing is wrong, but it has not been corrected! The final chapter deals with designing with adhesives. No examples of drawings showing assembly with adhesives are given, and we are completely in the world of design, not draughting, techniques. None of the finished drawings shown would be acceptable in my drawing office. The authors need to decide whether they are producing a Draughting or a Design Manual. The illustrations should ALL be up to date with the latest standards they claim to be presenting, and comply in every detail. They should represent the best of the draughtsman's art, not the typical products of those who have not kept up to date with the standards.

The Making of a Technical Artist - Engineering Drawing

Manufacturing of any structure, product or part actually begins in the human mind. There is a way to project that image out from the intangible realms of the mind into the more mundane realms of matter. It combines art and science and is known as engineering drawing as we shall learn here. The Combo – Engineering & Drawing Most of us understand engineering as a sophisticated discipline where everything goes by strict rules defined by various theorems, laws, and corollaries. Drawing on the other hand is considered to be an artistic feature where there are hardly any limitations except ones placed by the mind of the artist. So how would you perceive something which consisted of these extremes of strictness and freedom? Well, that is what engineering drawing is all about and you will see in the subsequent sections Is it an art or science? Actually, engineering drawing refers to the art and science of representing engineering objects on paper. It is an art since drawing is involved, which is obviously an art, whilst it is science at the same time since rules and regulations have to be followed in making that drawings, much unlike a purely art work which has no such restrictions. This may seem to be a severe restriction to the more sensitive type of people but thankfully this is what keeps the engineering world going. Just imagine a bridge or a building built from a drawing which doesn’t follow any rules except imagination. The day would not be far when such a structure would remain in imagination only after being dissipated at the altar of history.

Relationship to model-based definition (MBD/DPD)

For centuries, engineering drawing was the sole method of transferring information from design into manufacture. In recent decades another method has arisen, called model-based definition (MBD) or digital product definition (DPD). In MBD, the information captured by the CAD software app is fed automatically into a CAM app (computer-aided manufacturing), and is translated via postprocessor into other languages such as G-code, which is executed by a CNC machine tool (computer numerical control). Thus today it is often the case that the information travels from the mind of the designer into the manufactured component without having ever been codified by an engineering drawing. In MBD, the dataset, not a drawing, is the legal instrument. The term "technical data package" (TDP) is now used to refer to the complete package of information (in one medium or another) that communicates information from design to production (such as 3D-model datasets, engineering drawings, engineering change orders (ECOs), spec revisions and addenda, and so on). However, even in the MBD era, where theoretically production could happen without any drawings or humans at all, it is still the case that drawings and humans are involved. It still takes CAD/CAM programmers, CNC setup workers, and CNC operators to do manufacturing, as well as other people such as quality assurance staff (inspectors) and logistics staff (for materials handling, shipping-and-receiving, and front office functions). These workers often use drawings in the course of their work that have been produced by rendering and plotting (printing) from the MBD dataset. When proper procedures are being followed, a clear chain of precedence is always documented, such that when a person looks at a drawing, s/he is told by a note thereon that this drawing is not the governing instrument (because the MBD dataset is). In these cases, the drawing is still a useful document, although legally it is classified as "for reference only", meaning that if any controversies or discrepancies arise, it is the MBD dataset, not the drawing, that governs.

BSI British Standards launches drawing practice guide to help students survive in the real world

Teachers of Design and Technology and students of Applied Engineering or Manufacturing at GCSE, GNVQ or Advanced VCE level now have access to an essential guide to the conversion of design concepts into instructions for manufacturers. BSI British Standards has launched PP 8888-1, A guide for schools and colleges to BS 8888:2006, Technical Product Specification. This guide highlights the relationship between the process of quality management of products designed and manufactured in the classroom, and good industrial practice. By raising students’ awareness of these links, they will be better prepared to participate in the rapidly changing technologies of today’s world. The guide explains how to ensure that design concepts conform to current international technical drawing practices through the use of general principles, indications of dimensions and the employment of technical product documentation and specifications as specified in BS 8888:2006. This demonstration of effective communication tools between designers, manufacturers and quality managers will help prepare students for the real world of commerce and provide relevance to their everyday studies. This Guide to BS 8888 includes sections on all the main areas contained in current syllabi, such as orthographic layouts, dimensioning, sectioning, assembled views, exploded views and part lists. All examples are taken from BS 8888:2006. What does PP 8888-1 contain? • Design brief; function; specifications • Orthographic layouts • Dimensioning and sectioning • Assembled views, exploded views and parts lists • An introduction to communicating product design • Layout of drawing; line work; lettering; numerals; style • Projection and presentation method • Representing standard components • Dimensioning of technical drawings • Glossary Phil Childs, Chairman of the BSI Technical Committee responsible for Technical Product Specifications, said, “PP 8888-1 provides an insight into the requirements of BS 8888 so that both students and teachers can understand the rudiments of technical drawing. It should help show why it is necessary to convey the Engineer’s intent in a consistent pictorial manner so that both the maker and verifier of the component can understand it.” For the full list of contents, preface and sample chapter please visit www.bsigroup.com/PP8888-1. For orders, please contact: BSI Customer Services Tel: +44 (0)20 8996 9001 Fax: +44 (0)20 8996 7001 Email: orders@bsi-global.com

Engineering drawings: common features

Drawings convey the following critical information: Geometry – the shape of the object; represented as views; how the object will look when it is viewed from various angles, such as front, top, side, etc. Dimensions – the size of the object is captured in accepted units. tolerances – the allowable variations for each dimension. Material – represents what the item is made of. Finish – specifies the surface quality of the item, functional or cosmetic. For example, a mass-marketed product usually requires a much higher surface quality than, say, a component that goes inside industrial machinery. Line styles and types Standard engineering drawing line types A variety of line styles graphically represent physical objects. Types of lines include the following: visible – are continuous lines used to depict edges directly visible from a particular angle. hidden – are short-dashed lines that may be used to represent edges that are not directly visible. center – are alternately long- and short-dashed lines that may be used to represent the axes of circular features. cutting plane – are thin, medium-dashed lines, or thick alternately long- and double short-dashed that may be used to define sections for section views. section – are thin lines in a pattern (pattern determined by the material being "cut" or "sectioned") used to indicate surfaces in section views resulting from "cutting." Section lines are commonly referred to as "cross-hatching." phantom - (not shown) are alternately long- and double short-dashed thin lines used to represent a feature or component that is not part of the specified part or assembly. E.g. billet ends that may be used for testing, or the machined product that is the focus of a tooling drawing. Lines can also be classified by a letter classification in which each line is given a letter. Type A lines show the outline of the feature of an object. They are the thickest lines on a drawing and done with a pencil softer than HB. Type B lines are dimension lines and are used for dimensioning, projecting, extending, or leaders. A harder pencil should be used, such as a 2H. Type C lines are used for breaks when the whole object is not shown. They are freehand drawn and only for short breaks. 2H pencil Type D lines are similar to Type C, except they are zigzagged and only for longer breaks. 2H pencil Type E lines indicate hidden outlines of internal features of an object. They are dotted lines. 2H pencil Type F lines are Type F[typo] lines, except they are used for drawings in electrotechnology. 2H pencil Type G lines are used for centre lines. They are dotted lines, but a long line of 10–20 mm, then a gap, then a small line of 2 mm. 2H pencil Type H lines are the same as Type G, except that every second long line is thicker. They indicate the cutting plane of an object. 2H pencil Type K lines indicate the alternate positions of an object and the line taken by that object. They are drawn with a long line of 10–20 mm, then a small gap, then a small line of 2 mm, then a gap, then another small line. 2H pencil.

Drawing Braket

DRAWING WORK BRAKET

Getting Started in CAD

Introduction: Is it time to abandon the trusted paper and pencil? If I begin to depend on the computer to assist in my design work will I face all sorts of issues such as corrupted files and lost drawings? After all, a pencil drawing on paper can be stored in a file cabinet and will stay put. Paper is compact, it is cheaper by far than the cheapest computer, lasts for years, it can be dropped into a file drawer and accessed days or years later without an expensive terminal. I have all the knowledge I need about drawing already and will face having to buy "programs" costing hundreds and even thousands of dollars before creating even a simple sketch. I will face having to learn a whole lot of skills I do not now have. My work will be compared with lots of people who already have these skills. How is drawing with a computer accomplished? What is the best software to begin with, to stay with for the long haul? Should I learn the standard drawing programs like AutoCAD, Corel and Adobe? Can my current computer handle the special requirements of CAD? These and other questions for the CAD student will be answered in the following article. Why Start in CAD?: There are five reasons why people start using CAD: 1. File Sharing: Clients, equipment suppliers, contractors, lenders, regulators and others may have requested that drawings be sent to them over the Internet. Scanning hand drawn designs with a scanner for transmission has limitations. Bitmaps resulting from scanners reduce the detail of drawings so that information may be lost. Pencil drawings and blue-prints are particularly hard to scan due to the large amount of background information that clutters up the final image and may require long sessions of editing before the image is clean enough to send. Also, the bitmap image, depending on resolution, may become a huge file that takes forever to send and receive and takes up too much storage space. All good CAD programs have convenient file sharing utilities that will translate drawings into standard formats such as DWG and DXF and others that can be easily and conveniently sent and received on the net. 2. Design Efficiency: Designing in the real world often requires the use of repetitive images and standard drawings. These standard drawings may be yours or commercially available drawings such as available here. Believe me, the computer can store, manipulate and manage your graphics much better than a metal file cabinet. Also, as government regulations increase each year, officials often want only small changes to a series of complex drawings. The computer makes creating and changing drawings relatively simple with a series of standard drawings and mouse clicks rather than starting from scratch each time a new drawing is needed. 3. Organizing Work: At some point in your business, searching for a certain drawing or a special detail begins to take up time. Having ten years of drawings fit on one or two CDs has some advantages. Computerized drawings force the designer to constantly backup, organize and simplify the products of the design process. Believe it or not, the computer can help in the organization and storage of drawings, for both the compulsive saver and the impulsive artist. 4. Just Keeping Up: As time goes on, the computer, the Internet, the cell-phone force themselves on us and we give in. To keep fighting may help one's image as an independent thinker, but it will not help a bottom line. When tools such as CAD become industry standards, avoiding their use may isolate the holdout designer from others in the marketplace favoring the competition. 5. Improving Job Skills: Many schools offer classes in CAD. There is a vast range of teachers and programs available. Many are not very useful. A term of several weeks of study will not be enough to prepare you for a job, but you will get to experience what CAD drawing feels like. Many new graduates from qualified CAD schools are not useful in a tech position without a lot of practical experience. You will have to learn a lot in any CAD job that is not taught in any school. The diploma may just get you inside the door. Time spent at the computer, solving problems on your own develops the skills you will need quicker than classes in my opinion. Drawing Basics: The most important difference between CAD drawings and other computer graphics is the way the drawing is saved and used. Computer images (non CAD images) are bitmaps. Bitmaps are a grid made up of thousands of dots. Bitmap images lend themselves to computers because the monitor screens and printers already talk the language of bitmaps, a map made up of tiny bits. The smallest bits on the screen you are viewing is 72 pixels (picture elements) per inch. There is no point in providing images on your website that has more than 72 pixels per inch because the screen will not be able to show the larger detail. When you encounter a slow loading photo on a website it probably is saved on the server to a higher resolution than 72 pixels per inch. The CAD drawing, however, is like a pencil drawing made up of lots of lines. This is a vector image. Each line in the vector drawing is a mathematical curve. When you click the mouse to start and finish a line, the resulting line becomes a mathematical formula with a point of beginning, an end point, a thickness, a color, and a style (dashed, solid, dotted etc). CAD drawings being made up of vectors are saved as a list of mathematical formulas for each line based on a point of origin. Resolution or scale of the drawing or the details of each individual line or point can be changed without altering the other objects in the drawing. This is why this type of drawing is more useful than a bitmap. Take a look at the drawing below. It is a jpg file downloaded from the eco-nomic server and is a bitmap file as are all images on internet WebPages. It is 72 dots per inch for optimum viewing on your computer screen. DXF of the DRAWING (webmaster note: DXF and DWG files can be difficult to download on some computers - we recommend right clicking on the underlined links to the left and saving them first (choose "save target as. . .") before opening.) DXF is a universal drawing exchange format developed by AutoDesk for sending vector files. Fortunately this idea for drawing exchange has endured. Once you download and click to open this file, your drawing program should display the CAD drawing. Experiment with the drawing by turning on and off (see and hide) separate layers in the downloaded file. The exterior features of the car and the interior and motor are in different colors and on different layers. This is how CAD drawings can combine information for reference or extract certain views for printing, viewing or other reasons. The car for instance can be viewed and saved as the body only (red lines) without the motor and the hidden interior details (blue lines). DWG of the DRAWING in AutoCAD® 2004 The AutoCAD business model will not easily allow older copies of the software to open drawing files created in newer versions. That is, if I have AutoCAD 2004, and someone sends me a drawing created in AutoCAD 2008, I will not be able to open it easily. AutoDesk claims that it would be too hard to constantly make newer drawings compatible with older versions. They may have a point. However Adobe has not claimed this restriction and have managed to make all PDF files mostly universally readable in all versions of their software. PDF of the Drawing Most computers can now open Adobe PDF files. This will give you the general appearance of a vector drawing especially when you zoom in. However Acrobat files by nature discourage editing and altering. PDF files are sort of half way between vector drawings and bitmaps. Your computer if it can read this image has downloaded a reader from Adobe that creates a "posterized proxy image" that can be scaled and printed like a vector image, but unlike a vector file, this format is not for editing. GCD GENERIC CADD DRAWING File Just for fun, here is a GCD file of the car created in the program I used to use every day, Generic CAD. See if your software can recognize it. More About Vectors: Vector drawings are used for mechanical drawing and design because the shapes of the objects being designed, being exact mathematical shapes, can be modified and duplicated with very few commands (keystrokes). Lets say you have a drawing of a tank and you want to stretch it out a little to make it longer. With a CAD drawing you can grab one end of the tank with the mouse and pull. The dimensions shown on the drawing will automatically change to reflect the new dimensions. Also, the area and volume of the new tank size can be instantly calculated. Try that with a bitmap. Also text in the drawing can be edited even if it runs over parts of the drawing. Also parts of the design can be grabbed, erased, flipped, changed and copied without disturbing or changing the basic drawing. Designers always have favorite parts such as pumps, tanks and plumbing fittings that appear in all designs. The CAD operator can create standard parts called components or blocks which can be easily dropped into a drawing when needed with a few mouse clicks. This cut and paste feature is a great time saver and applies to such ordinary things as north arrows and title blocks as well as drawing parts and entire pages of details. The Drawing Process: Drawing in CAD is not exactly like drawing with a pen or pencil. The mouse is used to drag a point across the screen where you click to finish a line. If this sounds awkward, it is. However, certain features make up for the awkwardness. You can, once the line is drawn, tweak and twist it to suit your needs. A line can be started by "snapping" it to connect to another point. Note the drawing above where smooth curves connect to straight lines without a bump. Car bodies are generally composed of compound curves and gentle arcs. Cad drawings create these complex forms from lowly straight lines, arcs and the occasional spiral. In the same way that a word processor is, lets face it, a lot of ways, better than a typewriter, CAD programs also allow changes to already drawn objects. You may move, copy, bend, trim any line or set of lines in the drawing. Drawing tangents to circles, angles and geometric shapes of all kinds are done with a few clicks. CAD programs have special commands that shortcut operations. Multiple trims, rotary copy and move point are three examples of this type of command. Every good CAD program has dozens to hundreds of these shortcuts. The operator is free to make objects in the long way or discover a time saving command. I find cool shortcuts in even the oldest programs. Experience develops special short-cuts and tricks that will increase your speed. The CAD program understands geometry in ways that will impress you as a new user, guaranteed. One word of caution: You will lose an important drawing more than once as you learn how to prepare and organize your work. This will happen under a stiff deadline, and your drawing will either disappear, become hopelessly corrupted, or revert to a few stray lines. The CAD thing has never been a priority of Windows which is essentially a word processing and business operating system. CAD developers are aware of this and work around this constraint as best they can. You will wind up in conversation with a special club of nerds who are often at odds with the computer industry. You will probably demand special attention from your computer tech and sales people and hopefully you will get the help you need from time to time. I have been fortunate in my area to have found sympathetic support. Layers: Drawings can be built up with several layers. Layers are like transparent sheets that build up to form the final drawing. Each layer can be changed, printed or edited without changing the other layers. The drawing can show the top and the interior of a pump chamber, the electrical wiring, survey lines, easements, the plumbing etc all on the same drawing. Certain layers can be turned on or off for printing or display depending where the emphasis is to be placed. Most CAD programs can handle several hundred layers. Scale changes are simple to make: CAD drawings can be shown at any scale. When creating a septic design, the drainfield details can be created on the same drawing as the site plan. The final results can be cut out of the overall plan for separate sheets such as the site plan, the drainfield, the tank and pump chamber, etc. It is possible to zoom in to fill the screen with a single screw head from the control panel and zoom out to show the entire county that the system will be built in, all at an accuracy of six decimal places of an inch. How Much Computer Do You Need? When I started in CAD about 1990, I think the hard drive had twenty MB (Megabytes) of space. After drawing each line, I had to wait for a second or two for the computer to recalculate the vectors in the drawing. The screen would blink off for a second. Drawings had to be saved on floppies to keep space on the drive to run the program. As the drawing grew, the computer ran slower and slower. Sometimes it ground to a halt and another sheet was required. After about 1993, computers began to catch up to the CAD programs following the invention of the math co-processors, modular ram and larger hard drives. Today, the playing of video games and movies on computer and the Internet have pushed computers beyond the needs of any small design firm's CAD program. Any decent Internet computer will work for CAD. Windows XP is a good operating system for a CAD computer. If you have an older computer, do the check below. You may have to upgrade to the minimum required system. Most CAD operators avoid new operating systems. Windows Vista and 7 have shown problems running some older CAD programs. Buying a new computer will sometimes force you to visit compatibility limbo. Minimum Clock Speed: Older machines used to run at CPU CLOCK or CPU TYPE of 200 Hz or 533 Hz etc. This is the speed of your processor. Any computer bought in the last seven years should have enough speed for running all CAD programs if it is healthy. Hard Drive Space: Most CAD programs need a few hundred MB of free space or more before loading the CAD program and this does not include the space required for the drawings themselves which could be as much as a 5 MB or much more per drawing. To check your free space, go to your desktop or Control Panel and double click on My Computer. Right click on C: drive and click on "Properties" on the bottom of the list. The pie diagram that opens shows your Free Space which is where you load and run your CAD program. Do not attempt to run CAD if you do not have at least 25% free space on the hard drive following the installation of the software. Hard drives are cheap. A business program may not experience the same kinds of weird problems as a CAD computer running out of resources. So, don't take the advice of someone without CAD experience even if they are a qualified nerd. RAM: To check your RAM, at the bottom of your screen, Click Start, Settings, Control Panel, and double click on the System icon. The bottom line on the General tab will state your RAM in Megabytes or Gigabytes. You should have at least a Gig of RAM. Upgrading your Ram today is cheap but it must match your computer and your existing RAM. If your machine is a few years old, this may not be a simple upgrade. The software manufacturer will tell you the minimum required for your CAD program. Choosing Software: There is an array of drawing programs out there. Although Corel and Adobe have a good ability to create and modify vector drawings, these are drawing programs, not CAD programs. You will become frustrated marching endlessly through the menu maze in a simple drawing assignment. The goal of the CAD program is to allow the operator to create precision plans in scale, often in large format drawings to be plotted into drawing sets for the construction of structures. The bulk of drawing programs are used to create graphic images, usually bitmaps, for graphic presentation on screen or in print. Most web artists and graphic designers would find the graphic possibilities of CAD software quite limited. However for a designer of structures, a precision hand drawing or CAD drawing has no substitute. What About AutoCAD and AutoCAD LT? I have the latest software available from AutoDesk Retail and never use it. AutoCAD is the standard in the building, mapping and manufacturing industries. If you aspire to a job in this area, then spend the time and the four plus thousand dollars and learn all the details of the latest release. However, the capabilities of the program are too vast in my view to meet the simple needs of a small design office. The same applies to AutoCAD LT, the stripped down version. For CAD drawing, I personally use an old DOS based CAD program called Generic CAD which was bought up by AutoCAD in the mid 90's and put to death. There are still many loyal users out there. The beauty of this program is that all the drawing commands do not require the use of drop down menus. Simple two letter commands with the left hand on the keyboard control all drawing functions. The mouse in the other hand never leaves the drawing. This simple setup has never been embraced by the industry. Alas, the simple way is simply not enough. In most standard CAD programs, the rampant menus either clutter up the drawing screen when not needed or slam shut prematurely. So What Is Out There? There used to be several programs out there that would do a good job for $100 or so. My personal favorite, Generic CAD sadly has expired. I have made it run on everything before Windows XP Professional. Because printers and plotters must talk to the CAD program, staying loyal to older programs however good will eventually let you down. Visual CADD 5.0. emulates many of the great features of Generic and even opens Generic GCD drawings. Although I yearn for something better, I use this software every day. There will probably never be a drawing software as intuitive and nimble as Generic, but Visual is close enough for now. However they are long overdue for any upgrades and their website has more than a few tumbleweeds blowing around. Drawing exchange between computers and programs is happening more all the time, particularly over the internet. PDF's are simply the universal format for drawing exchange. Drawings in PDF format can be saved in scale for large format printing. Quality is only good enough for print quality and the PDF file can not transmit precision values, but most communication, particularly to clients or regulators for general discussion, these drawings are more than adequate. Your CAD program must be able to print to PDF. I am rewriting this section and trying out some new software - more on this important topic later. The Learning Process: Go ahead and install the software on your machine. Then create a folder and a file for your work and constantly save to that folder and file. Once you start drawing, your files will grow and multiply. I recommend that you create a file system by year that uses short file names of no more than 8 characters. I start each file with the year and designate the jobs in sequential order followed by the sheet designation, aa ,ab ,ac ,etc: i.e. 03000aa. In this way, you can usually identify a stray drawing, or find a specific job by doing a search of your storage drive. Next, Start Drawing: Learning CAD drawing takes about as much time as learning to drive a car. You will get places as you learn, but don't do rush hour. The basic drawing is created first with dimensions and text added after. You will become frustrated while trying to do simple things. Changing line width or style, customizing drawing settings and choosing options from vast menus can take forever as you learn the system. The books that come with the programs seem to be mostly useless, except for the exercises in some. The help menus never seem to have specific answers. You are guaranteed to have crashes, blue screens, black screens, lost files etc. I once created two identical files connected with a line. Technical support for AutoCAD asked me to send it to them for their private collection. It could not be opened and that day spent drawing was lost. It helps to have a specific job to do in CAD, a floor plan for a house to build, a pattern for a fabricator to cut, or some other "real" project. Attempting to learn CAD on your own, simply to enhance your attractiveness to a potential employer is unlikely to bear fruit. Remember, if you are job hunting, you will be competing with experienced operators with books of work samples. Your objective should be the same as someone learning a new language. You must become conversational. Be prepared to create a dozen drawings. By that time you will be proud of your work, and a potential employer, or client will see value in the results. If you are stuck for a project to start with, reconstruct the floor plan for your own apartment or house. Get out your tape measure and a note pad and pencil, and measure everything about your space including the toilet, sinks and furniture. Now get on the computer and produce a scale drawing of everything. Note wall widths and drawing details such as door swing arcs and railings. This will require the knowledge of trimming lines to exact length, parallel lines, scale, arcs, and other basic operations. Name and save every drawing to your hard drive. Just play around and see what you can do. Use the help menu as you go. If you become stuck, find a friend who is literate in CAD. Cook them dinner and ask for support. Community college classes will probably only teach AutoCAD and are likely to be of limited help in your work. Dinking on your own and one-on-one help are the quickest ways to learning the language. I make available here a CAD drawing as an example. Click here to get an example of a typical CAD septic design drawing. The drawing shows a tight site on a lakefront. This drawing set contains over 1,500 separate lines and parts and the file contains about 200 KB of data. This drawing is an example only of the septic designs for sale on this site in both the PDF and DXF fully editable CAD drawing exchange format. How to Print Your Work In Scale: (Editor's note: There are a lot of questions about scale and printing - we will expand this section soon). When you print your drawing, slap a ruler on it to make sure your printer is giving you the right scale. Trial and error is the best way to resolve errors of scale. Each software will have a slightly different approach to the scale problem. If your scale is 1/4 inch = 1 foot, a ten foot wall should be 2 and a half inches on the print. If this turns out not to be the size, then the scale is something different than you thought, and you must adjust the print scale, the paper size, or the drawing scale. The scale of your print must correspond exactly with the stated drawing scale. This is where you may wind up spending your time. Resist the temptation to change the scale of the drawing. Instead, adjust the size of the border to control the printing scale. You may need to chose a different scale entirely to fit everything on the page. Once you start printing, all this will make sense if it doesn't now. And with computers, once you get it right, it usually stays for good. Start a note book to jot down tips and operations as you go. Understanding Scale: Working in Generic, or any of the open scale software, keep your note book handy to jot down scales for different sizes of paper (letter size, 11 x 17, 2ft x 3 ft, etc). In your book, include standard blocks, type styles, macros and other bits and pieces of info helpful to the drawing experience. In Generic, one can start drawing in real scale without setting any parameters. Start a line and define the length from a millimeter to half way to the moon. "Zoom All" and the drawing fills the screen, no mater how small or large your project. AutoCAD on the other hand demands a finished paper size before drawing one line. Repeated adjustments are required as you draw to fit everything in. Starting in AutoCAD is hard, but printing is easy. In Generic, the opposite is true. I must throw a border around my drawing and arrange the layout before printing to get the exact scale. I must also scale the drawing to a known printer. I chose to load all my possible borders on one layer and find the one that fits my drawing. Throw all the others away and hit the print button. Easy. Again, this may all sound like gobble-de-gook, until you get into the drawing process. Don't give up. Push through the learning curve and experience the pleasure of creating clean accurate beautiful drawings for your business or pleasure. by John Glassco © 2001-2008

DRAWING BRAKET

DRAWING VALVE WARDROBE

DRAWING WORK VALVE WARDROBE

DRAWING VALVE WARDROBE

DRAWING SEKRUP

DRAWING WORK SEKRUP

DRAWING SEKRUP

DRAWING ORDERING CAKRAM

 DRAWING WORK ORDERING CAKRAM

D

DRAWING ORDERING CAKRAM

DRAWING PULI

 DRAWING WORK PULI

DRAWING PULI

DRAWING TROLI

 Schedule Drawing Troli 1

 Schedule Drawing Troli2

Drawing Troli

DRAWING WORM GEAR

 DRAWING WORK WORM GEAR

DRAWING WORM GEAR

DRAWING PINION GEAR

 DRAWING WORK PINION GEAR

DRAWING PINION GEAR

Drawing Straight Cover

 Drawing Work Straight Cover

Drawing Straight Cover

DRAWING STAGE DISK

 DRAWING STAGE DISK

 DRAWING WORK STAGE DISK

DRAWING ASSEMBLE GEAR

DRAWING WORK ASSEMBLE GEAR

DRAWING ASSEMBLE GEAR

DRAWING FLEXIBLW CLUTH

DRAWING WORK FLEXIBLE CLUTCH

DRAWING FLEXIBLE CLUTC

DRAWING RESERVOIR TANK

                                                                                             

DRAWING WORK RESERVOIR TANK

DRAWING RESERVOIR TANK

DRAWING CUTTING HALF RESERVOIR TANK

DRAWING GEAR

ddrawing work gear

dDRAWING GEAR

carriage drawing

  

                                                               (work drawing carriage)

                                                                                 CARRIAGE DRAWING

3D Modeling

3D modeling is the “process of developing a mathematical representation of any three-dimensional surface of object… via specialized software.”1 The process of 3D modeling and the cost of 3D modeling software are not easy to cope up with.2 Dedicated programs or application components are used in creating 3D models, and sometimes scene descriptions languages are involved. At other times, modeling is merely a part of a creation process.1 And the “most powerful tool” is our imagination.5 3D models are seen everywhere: in movies, in product designs, in advertisements, etc, but this does not mean that they are easily created.2 Creating 3D models is not as easy as creating 2D ones.5 3D models are “objects that are constructed on three planes.”2 They are composed of points connected by geometric entities. Examples of geometric entities are triangles, lines, curved surfaces, etc. There are two ways to create models: automatic and manual (which is similar to sculpting). They are made by hand, algorithmically, or scanned.1

3D computer graphics are “programs used to create 3D computer-generated imagery.” Some of these programs are specifically developed for certain objects only, such as chemical compounds or internal organs, and for certain processes only, such as skeletal animation.1,3 Users of 3D computer graphics interact with each other in forums to share their ideas. They share some tips and tricks on how to use graphics software. For example, three or more designers can collaborate on a project. A sub-forum is a “great place to share your experiences and do your Q&A with other users.” Groups are “starting points for discussions and collaborations.”5

Tessellation is the “process of transforming representations of objects, such as the middle point coordinate of a sphere and a point on its circumference into a polygon representation of a sphere.” This is used in breaking down primitives (spheres, cones, etc) to meshes (interconnected triangles). Lighting is an “important aspect of scene setup” and a “significant contributing factor to the resulting aesthetic and visual quality of the finished work.”1

The following are the three basic phases of the process of creating 3D graphics:2

1. 3D modeling
2. 3D animation
3. 3D rendering

Majority of solid models belongs to one of the following categories:1

* Solid
* Shell/Boundary

Solid models are realistic models that are hard to build. They have uses in non-visual simulations and in visual applications. Examples of non-visual simulations are medical and engineering simulations. Examples of visual applications are ray tracing and constructive solid geometry. Compared to solid models, shell/boundary models are easier to deal with. The exteriors of these objects define their boundaries. For instance, the focus of a shell/boundary model is its surface and its boundaries but not its volume.1

The following are digital approximations that are required to be used for nonfinite surfaces:1

* Polygonal meshes
* Point-based representations
* Level sets

Polygonal meshes are the “most common representation.” However, point-based representations are now gaining popularity. Level sets are a “useful representation for deforming surfaces which undergo many topological changes.” An example of these surfaces is fluids.1

The following are popular ways to represent models:1

* Polygonal modeling
* NURBS (Non-Uniform Rational B-Spline) modeling
* Splines and patches modeling
* Primitives modeling
* Sculpt modeling

The flexibility and ease of rendering have caused users to create a lot of models using polygonal modeling. NURBS modeling and splines and patches modeling are similar with each other in terms of their dependence to curved lines in defining visible surfaces. But if it is based on flexibility and ease of use, splines and patches modeling falls between the first two: polygonal modeling and NURBS modeling. Primitives modeling is more suitable to use in technical applications that does not have much organic shapes. It provides the following benefits: quick and easy construction, mathematically defined and absolutely precise forms, and simpler definition language. Geometric primitives serve as the building block of its models. Examples of these primitives are balls, cylinders, cones, etc.1

There are two types of sculpt modeling:1

* Displacement
* Volumetric

Both of them allow a very artistic exploration of the model. However, the former is more popular than the latter.1

Some modeling techniques are the following:1

* Constructive solid geometry
* Implicit surfaces
* Subdivision surfaces

3D modeling has advantages over 2D methods. These are the following:1

* Flexibility
* Ease of rendering
* Accurate photorealism

Flexibility is the “ability to change angles or animate images with quicker rendering of the changes.” Ease of rendering results from an automatic calculation and rendering, and mental visualization and estimation. Accurate photorealism is marked by minimized human errors in applying visual effects. However, sometimes it is difficult to achieve certain photorealistic effect. This is one disadvantage of 3D modeling.1

3D Modeling, Drafting, Product Design, Pro/ENGINEER, SolidWorks

Definition of Terms

3D Modeling, Drafting, Product Design, Pro/ENGINEER, SolidWorks

2D drawing

- An indirect and incomplete representation of an engineering product or system, subject to interpretation and error1

3D
- A real object or true depiction of real image1
3D computer graphics
- Graphics that use a three-dimensional representation of geometric data… that is stored in the computer for the purposes of performing calculations and rendering 2D images3
3D computer graphics software
- Programs used to create 3D computer-generated imagery9
3D model
- The product of 3D modeling2
- An object that is constructed on three planes27
3D modeling
- The process of developing a mathematical representation of any three-dimensional surface of object… via specialized software2
- The construction, manipulation, and storage of geometric objects to represent objects… around us or virtual objects17
3D printing
- A form of additive manufacturing technology where a three dimensional object is created by successive layers of material6
3D rendering
- The 3D computer graphics process of automatically converting 3D wire frame models into 2D images with 3D photorealistic effects on a computer5
3D wireframe
- Extension of 2D drafting12

Assembly modeling
- Technology and methods used by Computer-aided design and Product visualization computer software systems to handle multiple files that represent components within a product15

Computer-aided design (CAD)
- The use of computer technology for the design of objects, real or virtual12
- A combination of both hardware & software that helps architects, engineers and related professionals in the real estate & manufacturing industry worldwide18
- An important industrial art extensively used in many applications, including automotive, shipbuilding, and aerospace industries, industrial and architectural design, prosthetics, and many more12
- A major driving force for research in computational geometry, computer graphics (both hardware and software), and discrete differential geometry12
- Especially important technology within the scope of computer-aided technologies, with benefits such as lower product development costs and a greatly shortened design cycle12
- One of the many tools used by engineers and designers and is used in many ways depending on the profession of the user and the type of software in question12
- One part of the whole Digital Product Development (DPD) activity within the Product Lifecycle Management (PLM) process12
Computer-aided geometric design (CAGD)
- The design of geometric models for object shapes, in particular12
Computer animation or CGI animation
- The art of creating moving images with the use of computers10
- An artful blend of creative vision and technology31

Design intent
- How the creator of the part wants it to respond to changes and updates4
DWGgateway
- A free data translation tool that enables any AutoCAD software user to open and edit any DWG file, regardless of the version of AutoCAD it was made in4

eDrawings Professional
- An e-mail-enabled communication tool for reviewing 2D and 3D product design data across the extended product development team4
Electronic design automation (EDA or ECAD)
- A category of software tools for designing electronic systems such as printed circuit boards and integrated circuits26

Features
- Building blocks of the part4
- The shapes and operations that construct the part4
FeatureWorks
- Feature recognition software that lets designers make changes to static geometric data, increasing the value of translated files4
Flexibility
- The ability to change angles or animate images with quicker rendering of the changes2

Group
- A starting point for discussions and collaborations28

Innovation
- A vital ingredient of business success29
Interoperability
- The key issue which integrates various CAD CAM CAE tools1

Kinetic design
- Aesthetic design of physical movement32

Level sets
- A useful representation for deforming surfaces which undergo many topological changes2
Lighting
- An important aspect of scene setup2

MACRO (merge and correlate recorded output)
- Anything more than a single command19
- Rule or pattern that specifies how a certain input sequence should be mapped to an output sequence according to a defined procedure20
Macro program
- Computer programs that capture the user’s actions as if it is recording the user21
MoldflowXpress
- A mold design validation tool that was built into a solid modeling environment4

Parameters
- Constraints whose values determine the shape or geometry of the model or assembly4
Polygonal modeling
- An approach for modeling objects by representing or approximating their surfaces using polygons8
Print3D
- A 3D printing feature that allows users to convert their 3D CAD model to a .STL file and then have it sent to specialty manufacturers for quote4
Procedural modeling
- An umbrella term for a number of techniques in computer graphics to create 3D models and textures from sets of rules7
Product design
- The efficient and effective generation and development of ideas through a process that leads to new products30
Pro/ENGINEER
- A parametric, integrated 3D CAD/CAM/CAE solution created by Parametric Technology Corporation13
- The first to market with parametric, feature-based, associative solid modeling software13
- An integral part of a broader product development system developed by PTC13
- A piece of software that falls within the category of CAD/CAM/CAE and site alongside other similar products currently on the market13
- A feature based modeling architecture incorporated into a single database philosophy with advanced rule based design capabilities13

Skeletal animation
- A technique in computer animation, particularly in the animation of vertebrates, in which a character is represented in two parts: a surface representation used to draw the character… and a hierarchical set of bones used for animation only11
Solid modeling
- A consistent set of principles for mathematical and computer modeling of three dimensional solids14
SolidWorks
- A 3D mechanical CAD… program that runs on Microsoft Windows and was developed by Dassault Systèmes SolidWorks… a subsidiary of Dassault Systèmes4
- A competitor to CAD programs such as Pro/ENGINEER, I-DEAS, Unigraphics, and CATIA4
- A parasolid-based solid modeler4
SolidWorks Flow Simulation
- A tool that tests fluid-flow simulation and thermal analysis so designers can conduct tests on virtual prototypes4
SolidWorks MoldBase
- A catalog of standard mold base assemblies and components4
SolidWorks Motion
- A virtual prototyping tool that provides motion simulation capabilities to ensure designs function properly4
SolidWorks Simulation
- A design validation tool that shows engineers how their designs will behave as physical objects4
SolidWorks Simulation Premium
- A design validation tool that caters to designers without engineering background4
SolidWorks Sustainability
- A product that measures the environmental impact of designs while they are modeled in SolidWorks4
SolidWorks Toolbox
- A library of parts that uses “Smart Part” Technology to automatically select fasteners and assemble them in the desired sequence4
SolidWorks Utilities
- Software that lets designers find differences between two versions of the same part, or locate, modify, and suppress features within a model4
SolidWorks Viewer
- A free plug-in for viewing SolidWorks parts, assemblies, and drawings4
SolidWorks Workgroup PDM
- A PDM tool that allows SolidWorks users operating in teams of 10 members or less to work on designs concurrently4
Sub-forum
- A great place to share your experiences and do your Q&A with other users28

Technical drawing or Drafting
- The academic discipline of creating standardized technical drawings by architects, interior designers, drafters, design engineers, and related professionals16
- Integral communication of technical or engineering drawings and is the industrial arts sub-discipline that underlies all involved technical endeavors16
- Means of clearly and concisely communicating all of the information necessary to transform an idea or a concept into reality22
- Drawing plan, rendered to scale, used to communicate direction and specifics to a group of people creating something23
- Formal and precise way of communicating information about the shape, size, features and precision of physical objects24
- Universal language of engineering used in the design process for solving problems, quickly and accurately visualizing objects, and conducting analysis24
- A graphical representation of objects and structures24
- Expression of bodies by lines24
- Skill, a vocation25
Tessellation
- The process of transforming representations of objects, such as transforming the middle point coordinate of a sphere and a point on its circumference into a polygon representation of a sphere2
- A significant contributing factor to the resulting aesthetic and visual quality of the finished work2

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