IGCSE ICT CAD/CAM

Have an understanding of a broad range of ICT applications, including the use of 3D modelling:  Architecture  Manufacture  CAD/CAM The syllabus says you must:

if you wanted to design a new object or item to manufacture, it would have to be done by hand on paper. This shows a round object with 4 screw holes to be drilled. The drawing shows: 1.how far apart the screw holes should be placed (1.768 inches). 2. the scale that the drawing has been made to, in this cases 1 inch = 1.2 feet. Objects had to be designed and drawn like this because at this time, computers were very expensive and very rare. If you wanted to see different views or angles, you would have to make extra drawings.

 Creating paper designs of an object by hand was a highly skilled job and took many years of training. This method worked at the time BUT:  It takes a great deal of skill to draw something accurately, to scale  It took many years of training to learn the skills  It takes a long time to create each drawing  Many drawings were needed to see the object from different angles  Correcting mistakes was messy  It is not easy to make copies of the drawing.

Skill is still needed, however:  Lines can be shortened, lengthened, deleted or rotated at the click of a mouse button.  Different designs can be tried out very quickly to see the effect of changing things  Designs can be rotated and viewed from different angles.

 CAD is used to design a component.  Computer Aided Manufacturing (CAM) then makes use of that design to directly manufacture the component.  a computer is linked up to a cutting/drilling etc machine  The CAD file has all the details required for the CAM computer to convert the CAD drawing into a set of control commands for the cutting machine.

 Easy to change or adjust parts of the design  Different stages or versions of a design can be stored on the hard disk and accessed at any time.  Copies of the design can be produced by using a plotter or A3 printer  Design can be ed to another office for feedback

 The software can automatically check that the design meets any rules such as “the minimum width of any part must be more than 1mm”. While creating the design, an error message will display if any part of the design breaks this rule.  If one part of the design e.g. an aircraft wing, needs to be joined to another part of the design e.g. the body of an aircraft, then the software can check that both designs will fit together properly.

 Need very fast processor  Need a large, high quality monitor to be able to see the detail clearly on the screen  Training: CAD packages can be complex  Specialist CAD packages can be very expensive

Your assignment for today is to make sure your notes are complete!

 Go to the wiki page  Try the 2D and 3D CAD exercises  Complete the three quizzes Homework