WHAT IS CAD?

CAD was invented in 1966 by Pierre Bézier, a French engineer at the Arts et Métiers ParisTech with the help of his UNISURF program.

Computer-aided design software is a software program used by designers and engineers to create two-dimensional and three-dimensional models of physical components. CAD software has replaced the t-squares and protractors used in manual drafting which was the original method of making engineering designs.

CAD systems need hardware such as a high-quality graphics monitor, a mouse, light pen, or digitizing tablet for drawing, and a special printer or plotter for printing design specifications.

CAD/CAM (computer-aided design/computer-aided manufacturing) is a software program used to design products such as electronic circuit boards in computers and other devices.

How can CAD be used?

  • To produce detailed engineering designs through 3-D and 2-D drawings of the physical components of manufactured products.
  • To create the conceptual design, product layout, strength and dynamic analysis of assembly and the manufacturing processes themselves.
  • To prepare environmental impact reports, in which computer-aided designs are used in photographs to produce a rendering of the appearance when the new structures are built.

CAD software are specific in function and companies choose the software programs that suit their needs. They can be used to analyze the effect of stress-strain on components, calculate heat transfer, and measure the dynamic response of mechanisms and so on. However, the most widely accepted CAD software are the ones that can perform design and drawing operations. These CAD software can perform all the designing operations like: making various calculations, performing simulations of the designed components, checking them for stress, and more.

Which Professions or Careers Use CAD?

  • Civil engineers
  • Mechanical engineers
  • Aeronautical engineers
  • Architects
  • Structural engineers

History of Computer Aided Design

The development of CAD applications was a by-product of advances in the field of computer engineering and high-level computer programming languages. Though it started during the early days of the computer, CAD as we know it now was made possible through the capabilities provided by fourth generation computers.

What is the Meaning or Definition of CAD?

The meaning of CAD or CADD is Computer-Aided Design & Drafting. It is entirely different from the draw and paint procedures where measurement is an integral part. A “paint” procedure allows you to alter every pixel in a combination of pixels that are in a picture. For instance, if an image projects a house, building, and a vehicle, there seems to be no difference between them to distinguish one from the other. It is just a combination of colored dots you can handle with the help of painting gears.

Moreover, a “draw” procedure is an advanced plan which has various components like lines, circles and so on. This process can offer items to classify these elements into “building” and “car”, but the outcome is a picture analyzed regarding its look on paper.

One significant benefit of a CAD program is its utilization of real-world measurement. You can make a drawing of a vehicle in its original size and re-arrange it into sheets, where you can make prints of the scale you want. Correct measurements selected from the drawing should align with the object in the real world if the picture were formed properly.

For example, paint programs possess layers that act as different sheets of overlaid clear paper, but every layer will comprise a pixel-based picture. It is also interesting to know that paint and draw procedure have also included scaling features that are required for printing purposes or conversion of an image to be used on the web. Both of them cannot be utilized for structural detailing or accurate measurement.

Modern Historical Background of Computer Aided Design

In 1955, the Lincoln Laboratory of the Massachusetts Institute of Technology (MIT) developed the first SAGE (Semi Automatic Ground Environment) system for the US Air Forces. The system used a cathode ray tube screen to display radar information.

In 1962, Ivan Sutherland developed the Sketchpad system based on his Ph.D thesis “A Machines Graphics Communications System” also at the MIT’s Lincoln Laboratory. The thesis was the foundation of interactive computer graphics. Sutherland proposed the idea of using a keyboard and stylus to draw an image on a screen. During this period, ITEK and General Motors also developed a project called “The Electronic Drafting Machine” which used a vector display with hard disk refresh memory, a PDP-1 computer from Digital Equipment Corp, and a tablet and electronic pen as the input media.

Modern Introduction and How Modern CAD Started

In 1965, the first CAD which was developed using the ITEK Control Data Corp’s design was sold for $500,000. The following years saw a lot of scientists coming out with different innovations in the CAD industry. Companies such as Computervision, Textronic, and Dassault came out with industry leading CAD products. Leading companies in the automotive and aeronautics industries including Chrysler, Ford, Lockheed and General Motors adopted these technologies. In 1981, 3D/Eye Inc. was established as the pioneer of 3D graphics technology.

The Global Diffusion of CAD

John Walker and a team of like-minded people founded AutoCAD 1982. Their goal was to produce a PC version of CAD with a price tag under $1000. The Universal Data Transfer System STEP (Standard for the Exchange of Product Model Data) was launched in 1983. Two years later MicroStation was presented, a CAD development for PCs, based on Bentley System’s PseudoStation, which allowed viewing drawings in IGES format.

Back in the 1990s, McDonnell Douglas (Boeing) selected the Unigraphics system for his company. In 1992, the first AutoCAD on the Sun platform was released, and the first version for Microsoft Windows (version 12) was released three years later.

In 1997, Autodesk developed AutoCAD R14. The R14 was a rebirth of AutoCAD. The program was completely rewritten, and it was given a simple interface that was better and faster than its older versions. The AutoCAD 14 became an industry standard for other CAD software due to the increased productivity and quality it brought to work.

From the year 2000, we saw new software such as the ArchiCAD (in its versions 6.5 to 14) oriented to a design by parametric objects built in an integrated 2D / 3D environment, with a clear architectural orientation.  We also saw Sketchup, which revolutionized the concept of CAD by incorporating the idea of intuitive construction using object lines, it’s similar to the traditional manual drawing, but with the contribution of an associated three-dimensional construction.

BIM (Building Integrated Model) was developed recently and provides interchangeability and interoperability between computer-aided design programs such as AutoCAD, ArchiCAD, Sketchup and other specific use software.

Why Do We Need CAD Software?

This technology makes product design more efficient by automating manual processes. With 3D CAD software, designers can also do solid modeling and create three-dimensional representations of their products.

CAD software is mostly used for designing and drafting. Some of the benefits of using CAD systems include:

  • Increased productivity of the designer: The CAD software helps the designer in visualizing the final product that is to be made, its subassemblies and the building components. It provides animation which can be used to check how the finished product will work and make needed adjustments. CAD software helps the designer to synthesize, analyze, and document the design which leads to higher productivity regarding cost and project completion periods.
  • Improve the quality of the design: With CAD programs, the designers can use specific tools which help in undertaking specific engineering analysis. This helps in identifying flaws in the design, thereby reducing error and production time.
  • Better communications: With CAD software, more accurate and standardized drawings which are free from errors can quickly be produced and documented.
  • Creating documentation of the design process: CAD software makes the documentation of designs, such as geometries and dimensions of the product, its subassemblies, and its components, material specifications for the components, and bill of materials for the components easy.
  • Creating the database for manufacturing: CAD also helps to create a database for manufacturing by storing products and component drawings, materials required for the components, their dimensions, shape, and so on.
  • Saving of design data and drawings: CAD also helps to keep drawings and designs for future use.

CAD Software by Autodesk

Autodesk customers use CAD software for the design of ships, automobile, bicycles, prosthetics. The software can be used on Mac and Windows computers. CAD software is also included in Autodesk product suites for the design of buildings, products, factories and so on.

Is CAD Only Suitable for Design Drawings?

Customers can apply CAD to other designing activities, though the main function of CAD is to produce true-scale, structurally valid drawings. What other areas can be used with CAD?:

  • When scaling and relationships are important to an image, making the image in CAD and exporting it as a bitmap for touch up, and conversion can be very productive.
  • Visually accessed databases
  • It can be used to edit data in large drawings
  • Laser-cutting patterns for garment factories
  • Schematic design using CAD’s symbol libraries
  • Printed-circuit board layout
  • Page layout and web graphics

How Can You Learn CAD Drafting and Design?

Online Availability

CAD online courses are available

Requirements

High School Diploma or GED

Example CAD Courses

Courses such as Principles of Building Construction, Blueprint Reading, Technical Design, Cartographic Design Basics and Architectural Design are available.

CAD Continuing Education Programs

Though Bachelor’s degrees in CAD drafting are few, degrees in Architecture, Industrial and Product Design are not in short supply.

Educational Programs in CAD

While most vocational schools, universities and community colleges provide educational training in CAD software, other institutions provide associate’s degrees or CAD certifications in technology, while other schools introduce CAD courses through their engineering or drafting programs. Professional drafters are required to possess an associate’s degree or certificate while engineers and architects are expected to have at least a graduate-level education or baccalaureate according to the guidelines of the U.S Bureau of Labor Statistics. These are various means through which professional drafters can make use of the CAD software.

What are the Types of CAD?

There are two types of CAD which are the 2D and 3D. Drafts that are 2-dimensional are flat, while 3-dimensional and 2.5-dimensional drawings show the depth and space of design. Wireframe, surface and solid modeling can be used to calculate the dimensions of a design or simulate the appearance of the inner structure of the design.

Two-Dimensional CAD Drafting

CAD allows drafters to efficiently create simple, 2-dimensional drawings that are usually the foundation of more complex projects. For instance, 2D drafting may be used in the creation of the floor plan of a house.  2D drafting can be used to achieve the following tasks:

  • Scaling
  • Curve creation
  • Point construction
  • Rotating

2D CAD models are flat, two-dimensional drawings that provide overall dimensions, layouts, and information needed to reproduce or build the subject. Examples of these types of drawings can be seen in industries such as aerospace, architecture, automotive, cartography, civil engineering, interior design, landscaping and more.

Three-Dimensional CAD Drafting

A three-dimensional CAD model offers greater detail about the individual components and assemblies of a physical object. It is mostly used in the design of objects with many moving parts such as the intricate pieces used in the automotive or manufacturing industries.

3D modeling is used in the creation of solids, such as machine parts, bridges and buildings. CAD can be used to add or subtract volume from geometric forms, such as cylinders or spheres. With most CAD software, 3D models can be easily converted into 2D drawings to be presented as traditional drafting documents. 3D drafting is considered a more realistic approach to drafting because its renderings most accurately resemble real-life objects.

What is the Difference Between CAD and AutoCAD?

Computer-aided design (CAD) refers to the use of computers in the design of houses, office buildings, interiors and other things which were done with manual drafting. However, AutoCAD is specific CAD software employed by architects and designers for commercial design purposes.

AutoCAD is a patented product of Autodesk. AutoCAD provides users the ability to draft 2-D and 3-D designs and creates photorealistic rendering. There are several versions of the AutoCAD application for a variety of work types such as: architecture, piping design and mapping.

CAD Educational Programs

The U.S. Bureau of Labor Statistics reports that professional drafters usually require a minimum of a certificate or an associate’s degree. Architects and engineers need baccalaureate and graduate-level education. Community colleges, vocational schools and universities offer training in CAD software. Some schools offer entire certificate or associate’s degree programs in CAD technology, and some provide CAD courses through drafting or engineering programs. Some programs teach only the AutoCAD software while some use other CAD applications

Autodesk also provides training programs through authorized certification centers. These courses can prepare you to earn certification in AutoCAD from the vendor. Autodesk certification shows you are proficient at using the AutoCAD application.

Most Popular CAD Software

There are a lot of CAD software currently being used in different industries. The most popular CAD software is AutoCAD, while others such as CADopia, Catia, MathCAD, QuickCAD SolidWorks and so on have also gained wide acceptance. AutoCAD has been around for a long time and has many versions. Its latest version, AutoCAD 2009, has ribbon in its user interface similar to the one in Office 2007. AutoCAD is very expensive, but there are alternative CAD software with the same functions but at lower prices.

Key Skills for CAD

Technical drawing skills, understanding CAD software, engineering, manufacturing, architecture and design.

Work Environment

Office setting, construction sites, or other field sites.

CAD Professional Certifications

Different certification levels are available through Autodesk sponsored courses and exams such as AutoCAD Certified User, AutoCAD Certified Associate and AutoCAD Certified Professional.

What is DWG?

Drawing (DWG) is a computerized drawing file format used mainly by the AutoCAD program. The name of the extension .dwg was derived from “drawing” and was due to a three letter limitation from the protocols of the MS DOS Operating System. DWG files from different CAD programs are usually incompatible, but the need to read these files by other programs led to an exchange, import-export file, known as DXF (Drawing eXchange File), though many CAD programs are prepared to operate non-native with such files.

Because this file format has become an industry standard, the Free Software Foundation has created the LibreDWG libraries, similar to the non-free OpenDWG.2 libraries. DWG files store drawing information in three dimensions in vector form.