Computer Control and CAD/CAM

Designing and making by computer

Computers now sit at the heart of how products are designed and made. Designers use CAD, computer-aided design, to draw, model and test a product on screen before anything is built. That design can then drive CAM, computer-aided manufacture, where computers control the machines that cut and shape the material. Many products are made on computer numerical control machines that follow a program exactly, and many devices run on control systems that sense the world and respond to it. This module covers CAD and CAM, control machines, the idea of input, process and output, and the benefits and drawbacks of automation.

Control and CAD words

Learn these terms before the ideas are described. They name the tools of computer design and control.

Match each control term to its meaning

CAD against CAM

CAD and CAM work together but do different jobs. Keeping them apart is a common exam point.

What does CAD do?

What does CAD, computer-aided design, let a designer do?

• Design and model a product on a computer
• Physically cut the material by hand
• Sell the finished product in a shop
• Paint the product by hand

Input, process, output

Control systems all follow the same simple pattern: input, process, output. An input device, such as a sensor, detects a change in the world, like light, heat, movement or pressure. A process, run by a computer or control program, decides what to do about it. An output device then acts, turning a motor, lighting a lamp or sounding a buzzer. Think of an automatic door: a sensor detects a person, the control decides to open, and a motor is the output that moves the door. When you explain any control system, name the input, the process and the output, and you have described how it works.

Pick the benefits of automation

Select every genuine benefit of using automation and CAM in manufacturing.

• Parts are made precisely and consistently
• Products can be made quickly
• Machines can work continuously
• The machines cost nothing to buy or set up
• A badly written program will still make perfect parts

Order making a part with CAD and CAM

Put the steps of making a product with CAD and CAM in the correct order.

• Design the product on CAD software
• Test and edit the design on screen
• Send the design data to a CAM machine
• The CNC machine makes the part
• Check the finished part against the design

Complete the control facts

Designing a product on a computer is called _____. Using computers to control the making machines is called _____. A device that detects a change, such as light, is a _____. A control system follows the pattern input, process and _____.

One part, made by computer

Follow a small plastic bracket from idea to object. A designer draws it in three dimensions using CAD software, then tests it on screen, checking it fits and editing the shape until it is right, all without wasting any material. When the design is ready, its data is sent to a CAM machine. A computer numerical control cutter reads the data and shapes the plastic exactly to the design, making one bracket after another that are all identical. Finally the finished part is checked against the original design. Notice that the computer carried the design from screen to shelf, with precision at every step. That linked path from CAD to CAM is the heart of modern making.

Tap the input devices

Tap the TWO devices that are inputs in a control system.

• a light sensor
• a temperature sensor
• a motor
• a lamp

The technology run

Answer each one correctly to keep your lives. Choose the correct answer.

Apply the technology

Read each situation and choose the best answer.

• A designer wants to test and change a product before any material is cut. What should they use?
• An automatic light must switch on when a room goes dark. What is the input?
• A factory needs many identical parts made precisely. What suits this best?

Build a point about control

Choose the word for each gap to complete one clear point about control systems.

Explain computer control and CAD/CAM

A friend thinks products are still designed and made entirely by hand. Using what you have learned, explain how computers are used to design, make and control products.

• Explain what CAD and CAM are and how they link
• Explain what a CNC machine does
• Explain the input, process and output of a control system
• Explain the benefits and drawbacks of automation