First 599 words of the document:
Computer aided design CAD
CAD packages are used by engineers and designers to design many things including cars, bridges, ships, waterways,
circuit boards, computers, machinery, dams, chemical plants, oil rigs and buildings.
CAD packages have many features including:
Allowing the designer to draw an object in 2-dimensions (flat) and then having the software build and display a
3-dimensional, "solid" version of the design
Allowing the object to be rotated and viewed from different angles
"suggesting" suitable materials for constructing the objects, e.g. materials with sufficient strength or flexibility
calculating the stresses and strains that a structure will have to withstand and, where necessary, give warnings of
designs that are not safe
simulating and testing the finished design, e.g. where CAD is used to design an electronic circuit it can simulate
the operation of the circuit
Monitors used for CAD are usually large (e.g. 21" screens) and have high resolutions so as much as possible of the
design can be seen at the same time in as much detail as possible.
Graphics tablets are often used to construct drawings and trace images.
Where a hard copy (printout) is required, plotters, A4, A3 and A2 printers may be needed.
Using CAD software enables drawings to be done more quickly. Changes can be made without having to start the
whole drawing again and parts of the drawing which are needed more than once can be copied and duplicated as
many times as required. Many companies have large libraries of drawings held on disk which can be retrieved and
modified very rapidly. Very fine detail can be achieved by zooming in on the drawing and the tedious task of shading
areas can be done automatically by the computer.
Using a computer network a number of designers can work on the same project at the same time and workers
throughout the company, from the boardroom to the shop floor, can access drawings on their terminals to assist
them with their work and decision making.
CAD software is not just a drawing package. It can be sophisticated software that can calculate, from the dimensions
of the drawing, the weight, strains and stresses that the finished object will endure. In this way, weaknesses in
structures like bridges can be avoided. When using CAD software to design electronic circuits, the software can
simulate voltages to test the circuit even before it has been constructed.
Computer aided manufacture CAM
CAM is a process of aiding production in manufacturing companies by using computers to operate machines. Some
machines shape materials; three of the more common processes are lathing, milling and drilling. Other machines
transport the goods between one process and the next and computer-controlled robot arms may be involved in
spraying paint or welding joints.
The most effective method of production is to design products using a CAD package and then pass instructions
directly from this package to the machines able to manufacture the product (CAM). Data from the design software is
translated into instructions for guiding the lathes, milling and drilling machines. The whole process is fully automated.
The introduction of these systems into the manufacturing industry has:
increased production machines do not need breaks or sleep
dramatically reduced the number of workers
reduced the demand for machine operators
created the demand for skilled computer operators