4.1.6 Uses of ICT in Business/1 Computer-aided design (CAD) and Computer-aided manufacturing (CAM)

1. 4.1.6 Uses of ICT in Business/1Computer-aided design (CAD) and Computer-aided manufacturing (CAM)

2. Starter: What is CAD? What is CAM?

3. Main: CAD CAD = Computer Aided Design CAD is used by manufacturers and engineers to design things that will be built e.g. Toasters, cars, bridges, buildings CAD is usually vector-based software which is very powerful and often needs a lot of memory to run. There are two main types of packages - 2D (two dimensional) which concentrate on 'flat' drawings having width and height, for example, a garden design program. The other type of CAD package is 3D (three dimensional) which allow you to deal with depth as well, for example a kitchen design application

4. Main: Features of CAD packages • Ability to zoom in or out of a part of a design. • Ability to change 2D drawings to 3D surface models. • Ability to rotate a 3D design • No need to build a prototype (actual model) • Can add shading to a diagram to aid visualisation • Layers can be used with each layer adding more detail to the drawing (e.g. one layer showing the walls of the building, another the electrical circuits, another the plumbing) • Allows walk-through • As each appliance or unit is added, it is recorded and the costs are added up to give a final amount.

5. Main: Advantages of CAD Drawings are: • Easily stored and transferred ( digitised and can be sent via email) • Easily altered • Manipulated easily • Available in 3D • Easily scaled up and down • Use libraries of artwork to include in the diagrams e.g. trees, people etc. • Produce a list of components automatically, list of dimensions and parts needed to create the product • Stress/Strain calculations mean that the software will only allow you to design building that are safe. • Hatching , adding different types of shading to an image to add realism. • Rendering – using a computer to draw an image on a computer screen and this often means using ray-tracing to turn an outline sketch into a detailed image of a solid object.

6. Main: Examples of CAD • Producing kitchen or bathroom designs for customers • Producing the designs for a component that is to be manufactured • Used by architects for designing buildings • Used by gardeners/landscapers to design a garden • Used to produce engineering drawings • Used to produce maps and plans

7. Main: CAM CAM = Computer Aided Manufacturing If the machines used in manufacturing or testing are controlled by a computer, it is a CAM system.

8. Main: Features of CAM packages • Uses a computer • Takes the input from CAD packages and uses the information to produce a set of instructions to give to machinery to manufacture the article or component. • Used to program and control equipment • Products are made automatically • CAM equipment can be re-programmed to make new products or components with different dimensions.

9. Main: Advantages of CAM • Cheaper manufacture (as it is automatic so costs are reduced) • Faster time from design to manufacture • Better quality (no human involvement so no mistakes) • Lower wage cost (as less human involvement) • Machines can be re-programmed to make new products • Can make small quantities that would normally be uneconomical

10. Main: Examples of CAM • Used to manufacture components in car engines and gearboxes • Used to manufacture double glazed windows and conservatories

11. Hardware requirements for CAD and CAM

12. Input Devices • Keyboard • Mouse (2 buttons and a scroll wheel) • Space mouse

13. Main: Processing Speed CAD/CAM packages place large demands on the processor of a computer. Speed of processor CAD software needs to perform many complex calculations when scaling, transforming images or producing 3D models from 2D designs. The speed of the processor is the main influence on how fast the CAD system appears to the user. In order to speed up CAD systems, dual processors are used, meaning program instructions can be dealt with faster by allocating them between the processors.

14. Main: Processing Memory Memory Is used to hold programs and data which may need to be accessed immediately by the processor. Large amounts of RAM (random access memory) should be included and there should be space to add more RAM as future upgrades of the CAD software may require it.

15. Graphics Card • If an ordinary PC is used with CAD it may be necessary to change the graphics card as most graphic cards are designed with business uses and games in mind. • CAD places lots of demands on the graphics card. • The best graphics card will offer speed, stability and image quality. • A 3D graphics card is required to turn 2D designs into 3D designs.

16. Main: Output Devices - Screen Designers spend a lot of time looking at the screen so it needs to be: • As large as possible to reduce eye strain (min 17 inches) • Minimum resolution of 1024x768 pixels ( a pixel is the smallest dot of light on the screen) • Be flicker free with a very stable picture • Have a non-reflective coating on the screen to reduce glare

17. Main: Output Devices – Printers/Plotters • Detailed plans need to be printed on larger sheets of paper, so specialist plotters are used. • Drum plotters – these are used when drawings, plans and maps need to be printed on large sheets of paper.

18. Main: Output Devices - Machinery • Output from CAD design can be input into a CAM package to control machinery to make the item. • The output from the CAM package is the instructions to control devices, such as millers, lathes, cutters, drills, etc., that are used to automatically manufacture components or products.

19. CAD and CAM Software

20. Main: Pro/Desktop • This allows the visualisation of 3D objects on the screen which can be viewed from any viewpoint. • You can experiment with the colour and texture of the parts and look at them using different views. • There are a series of shapes contained in a library which you can select and drop onto the working area of the screen where the shapes can be sized and combined with other shapes to form an assembly. • One the shape has been assembled in 3D the material can be chosen and the mass and volume of the object can be determined. • Drawings other than 3D can also be produced which can aid manufacture. • It allows the designer to generate, design and model alternative ideas.

21. Main: ArtCAM • Is a CAD design and a CAM package. • It takes your 2D designs and turns them into 3D designs. • You can add textures and text on curved surfaces. • It can be exported into a CNC machine which includes lathes, laser cutters and routers.

22. Main: ProSketch • Is aimed at graphic design and design of textiles. It allows users to create initial sketches of garments and other textile products. • There is a library of objects including zips, buttons, sleeves, button holes, collars etc. • With another piece of software from the same company, users are able to select from a whole range of colours and textures of fabrics for their design, including stripes, spots, all-over colours, checks, etc. • The software allows you to drape the designed garment onto a drawn design such as a figurine.

23. Main: Websites for CAD/CAM • The following websites will allow you to download a trial version of the software to explore. • When looking at these websites think about the features they offer the user and the applications to which they are most suited. • www.prodesktop.net • www.artcampro.com • www.softwaresolutions.fibre2fashion.com/productDetail.aspx?refno=1760

24. Activity: 4 case studies In groups of 4 your will look at a different case study and answer the questions provided for each.

25. Extension : Trail of CAD Use Google Sketch Up to Design something of your choice.

26. Practice Questions: • (a) What do the abbreviations CAD and CAM stand for? (2) (b) Describe two features that you would expect to find in: (i) CAD software (ii) CAM software (4) 2. Explain two uses in which CAD/CAM software can be put. (2)

27. Practise Question: 3. An engineering company uses CAD systems to design components for car engines and gearboxes. • Give two advantages that CAD packages offer compared to producing designs and scale drawings manually. (2) • CAD software places demands on the computer used to run it. Describe the special hardware requirements for the successful running of CAD software. (3) 4. the engineering company is thinking of using CAM to help manufacture the components using information from the CAD software. Give two advantages of using CAM. (2)

28. Practise Questions: 5. (a) Explain what is meant by a CAD system and give two distinctly different applications for it. (4) (b) Explain what is meant by CAM. (3) 6. A garden design company is using a CAD package to help design gardens for their customers. Discuss the advantages and disadvantages of using CAD software for this purpose. (6).

29. Plenary: Split Quiz The class will be spilt down the middle. From the centre of the room a question will be asked. The 2 contestants will go head to head to gain a point for their team.

30. Exam question: 2. An architect uses specialist CAD software to design a new school. • Select any four of the following features of CAD software and describe an advantage of each to the architect when designing a new school from scratch. Rotate Zoom Costing Walk-through Hatching/rendering 3D modelling (4) (b) The architect and the people in her office use CAD software for long periods working on very detailed designs and drawings. State one health problem that could result from the use of a CAD system and explain how this health problem could be prevented (2).

31. More information on CAD and CAM: • http://www.teach-ict.com/gcse/software/cadcam/miniweb/index.htm • http://www.teach-ict.com/gcse/software/cadcam/starters_plenaries/gcsecadcamyesno.htm (CAD/CAM T/F quiz) • http://www.teach-ict.com/gcse/software/cadcam/starters_plenaries/flashcard.swf(matching game)