Computer-aided drafting and design (CADD), also known as CAD or computer-aided manufacturing (CAM), is the process of using special software programs to draw new products or buildings. It is used by drafting professionals as well as architects, engineers, product designers and builders to create a graphic representation of a project before it is built. What used to take hours to draw by hand can now be completed in minutes using a computer keyboard or mouse.
Up through the 1950s, all drafting work was completed by hand. This process was long and tedious, and a small mistake or design change could send the drafter back to the drawing board. In 1950, Dr. Paul J. Hanratty invented a numerically controlled program that allowed designers to draw simple lines with a computer. At the time, computers were the size of a room, so this type of program was not widely available, though Hanratty is still credited as the "Father of CAD" for his contribution.
By 1957, researchers at MIT had expanded upon Hanratty's work to create a program called "Pronto." Pronto allowed designers to draw more advanced objects with a computer, though use was still very limited due to computer availability and costs at the time.
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The First Modern CADD Program
From 1960 to 1980, aerospace and manufacturing firms like Ford and Lockheed Martin invested heavily in CAD programs for in-house use. Companies like these were among the only ones who could afford this new technology until the early 1970s. In 1972, Dr. Hanratty formed a company known as MCS, where he produced a program known as "Automated Drafting and Machining." This program not only worked on a smaller 16-bit computer, but also featured many of the commands used by modern CAD programs. Instead of numerical inputs, users operate a small table of drawing commands using a regular keyboard. This program originally came with only an 11-inch screen, but Hanratty's company was able to increase the screen size over the next few years.
In 1982, the Autodesk Co. introduced AutoCAD, still among the world's most widely used CAD programs. By 1986, "PC World" magazine had named AutoCAD the world's best CAD program, a trend that would continue for the next 10 years as Autodesk introduced more advanced versions of CAD throughout the decade.
In 1993, Autodesk introduced a 3D CAD program for DOS-based computers. As personal computers became more widely available throughout the 1990s, so did the use of CAD. By the 21st century, many 3D drawing and modeling programs were created, including Autodesk's Revit. Revit and similar modeling programs combine design, drafting and building-information modeling (BIM) to create more sustainable and efficient buildings.
One of the biggest deterrents to CAD development was the high cost and limited availability of computers and software during the early years of its introduction. In the 1970s, Dr. Hanratty's 16-bit CAD program sold for an average of $125,000. By 1982, Autodesk was able to sell CAD programs for under $1,000. By 2000, Autodesk's Chief Architect program, which combined 2D and 3D CAD options for professional users, could be purchased for $895. In 2010, simple CAD programs can be had for a few hundred dollars, making them available to most computer users.
CAD offers a variety of advantages over traditional hand-drawn plans and blueprints. It helps both the designer and the owner or developer visualize the finished product. By seeing what it will look like ahead of time, they are able to make changes before heavy investments are made. Engineers and scientists can analyze a product's design to ensure it will be structurally sound, or that it will operate as intended. CAD speeds up the design process so products are cheaper to make and can reach stores more quickly. It is also helpful for creating accurate images of an object so builders or manufacturers know exactly how the final product should look.