CAD stands for Computer Aided Design.

CAD systems consist of the hardware and software needed to enable designers to produce accurate plans and drawings.

A CAD workstation may be a standalone or a networked computer. It would have ...

• a powerful processor - needed for some of the processes such as 3D rendering.

• a powerful graphics card and a high resolution monitor.

• input devices such as mouse, light pen, graphics tablet, keyboard.

• output devices such as printer, graph plotter.

• backing store devices such as a hard drive for saving designs.

CAD software would allow a user to...

• Rotate: allows the architect to see the design from all angles.

• Stress/strain: Working out the weights materials can take. This allows the architect to see if there are any load bearing problems with the design before it is built. / Do calculations to see if the building is safe. Avoids disasters later on when building as the designer should build well within safety requirements.

• Wire drawing: Outline design (perspective) requires less processing to display.

• Walkthrough: allows the architect to see in virtual reality what the inside of the building will look like. You can view objects in 2D or 3D using different lighting effects, walkthroughs. An advantage being allows spatial awareness (size) of what the design looks like in relation to other features.

• Hatching/Rendering of surfaces. Different finishes or materials can be displayed. An advantage is you can do ‘what if’ type investigations to explore the best finishes.

• zoom for adding fine detail.

• draw lines, and polygons of any size.

• draw curves, circles.

• draw on a number of different layers.

• perform transformations such as scaling or rotating.

Some CAD software allows analysis of stresses, liquid flow etc...or testing of electronic circuits.

CNC machines may be..

• a lathe for turning metal or wood.

• milling machines for cutting metal shapes.

• drills

• welding machines

• soldering machines

• water jet machines

• lasers

• router or engraver

• robotic arms

Some CNC machines have automatic tool-changing facilities.

Advantages of CAD/CAM systems:

• good accuracy and precision.

• fine detail can be added.

• reliable and consistent results.

• fast development of designs.

• design facilities such as 3D views and walkthroughs and lighting changes can not easily be done on paper.

• easy editing of designs.

• some automatic calculations such as material costings.

Disadvantages of CAD/CAM systems:

• Expensive to buy and set up the hardware and software.

• Staff will need to be trained to use it.