Computer-aided design and manufacture

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Computer-aided design and manufacture

• Computer-aided design, or CAD, is the use of a
  computer to display designs, accept any changes
  to them and calculate and display the results.
• CAD has many different applications, which
  include-
• Designing new cars
• Bridge and building design and testing
• Printed circuit board (PCB) design
• Designing new aircraft
• Designing fitted kitchens.

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Making changes to a design requires a large
number of complex calculations. These need to be
performed as quickly as possible so that their
effect can be viewed straight away. A powerful
processor is required for this. A CAD system
also needs a high-resolution monitor so that
clear close-up detail can be seen on the screen.
Input to CAD systems is normally given using a
mouse and keyboard but other input devices such
as graphic tablets and scanners are also used.
Output from a CAD system is produced using a
high quality printer such as a laser printer or a
plotter.
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• The advantages of CAD systems are-
• Changes to a design can be made quickly and their
  effects seen straight away
• Designs can be viewed from any angle without
  being re-drawn
• Designs can be tested without the need to build
  expensive models or prototypes
• Drawings can be stored on disk and re-used at any
  time
• Designs can be instantly sent anywhere in the
  world using electronic communications
• Designs can be used directly in computer aided
  manufacturing processes.

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Computer-aided manufacture, or CAM, is the use of
a computer to control all or part of a
manufacturing process. Some examples of CAM
include the production of printed circuit boards,
car manufacture, pattern cutting for clothing
manufacture and making postage stamps. Very
often a CAM process follows directly on from a
CAD process, in such cases the complete design
and manufacture process is called CAD/CAM. The
main advantage of this approach is that the CAD
design can be used to generate the program which
will control the manufacturing process.
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The student shown in this picture has used CAD
software to prepare a design which he is going to
manufacture using the milling machine connected
to the computer behind him.
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• The advantages of CAM systems are-
• Products can be made very accurately and
  consistently
• Around the clock production is much cheaper
• A product's design can be modified without the
  need to bring production to a complete
  standstill
• Waste can be kept to a minimum.

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Disadvantages of CAD / CAM

• Can be very expensive to set up. A single
  industrial robot can cost millions
• It can take a long time to train people to use
  more complex equipment.
• Little need for poorly qualified workers.
• Fewer people are needed, and this can result in
  higher unemployment

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Computer Integrated Manufacture

• CIM systems are complex pieces of equipment that
  combine CAD and CAM
• e.g. a system that will respond automatically to
  changes made to the design of the product

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Questions

• What does CAD stand for?
• What does CAM stand for?
• Where would CAD / CAM be used?
• What do all CAD packages have in common?
• Why is it an advantage to use CAM?