National 4/5Graphic Communication

Advantages of CAD

3D Modelling

Computer Knowledge

You will need to know about how computers are used with Graphic Communication and how this impacts upon the design and manufacture of products.

You will learn about advantages of using CAD (Computer Aided Drawing).

You will need to know how to use some commands and techniques used in 3D CAD packages.

Advantages of CAD

Reduced storage space required. Previously, paper drawings would

have required whole rooms to store the drawings for a building.

Now this information can be stored on a single disk.

Advantages of CAD

Corrections can be made easily. Before, whole drawings may have had

to be reproduced on paper if a mistake has been made.

Now a single line is deleted and redrawn in the correct place.

It takes less time to produce drawings using CAD systems than traditional manual drawing methods.

Advantages of CAD – CAD library

Repetitive parts of the drawing can be saved and imported as part of a CAD library.

A CAD library stores frequently used symbols.

Paper drawings require objects to be redrawn each time manually which is time consuming.

Being able to call the parts in from a library saves the user time.

Advantages of CAD

Drawings offices often produce their drawings using a standard layout so that people can immediately identify the drawings as belonging to that particular company.

Templates can be set up on a computer to make this easier.

Advantages of CAD

CAD systems can be linked with CAM machines to produce objects straight from the drawings.

This is referred to as CAD/CAM CAM stands for Computer Aided

Manufacture. This is a cheaper and quicker method

of producing the final product.

Advantages of CAD

No matter what size of drawing is being produced CAD systems can be used to produce them accurately.

Grid Snap, Zoom and Attach commands are 3 examples of methods of producing accurate drawings easily.

Advantages of CAD – virtual reality

Designers can use powerful CAD computer packages to make virtual reality simulations of the layout of their buildings.

This means that the client can have a “look around” the building as a virtual tour before it is built and changes can be made at this early stage.

This results in a faster design of the building and a higher quality end product.

It is also cheaper to make any changes at this stage rather than while the building is being constructed.

Advantages of CAD – the Internet

On an ever greater scale, the Internet can be used to share plans and designs with anyone in the world that also has an Internet connection.

This means that specialised work can take place between different countries quickly and cheaply.

Another benefit is that multi national companies can have 24 hour designing happening in offices across the world.

3D Modelling

3D Modelling is widely used by most design companies to create their products.

There are many advantages of using 3D Modelling over old fashioned 2D CAD packages.

3D Modelling - Advantages

The main difference between 2D and 3D packages is that the actual model of an object is made 3D rather than 2D views of it.

Orthographic and pictorial views can be produced from the 3D model.

3D models can be animated to show movement.

Simulations can be run from 3D models. 3D printing means that products can be

manufactured directly from the 3D model of an object.

Animation

Computer animation shows how an object moves.

It is a set, predefined sequence that can only be watched, its outcome cannot be changed.

Animation - advantages

Some advantages of using simulation are: to describe how an object can be

assembledto use as a set of instructions for

people to follow.

Simulation

Computer simulation is when the user can interact with an object to effect the outcome.

When using computers to design things, we can use computer simulation to test components.

This could be a wide range of factors. It can range from testing brake systems, the

aerodynamic performance or cars or flight simulators.

Simulation - advantages

Some advantages of using computer simulation are:It is a safer way of training people.It is cheaper to test designs without

destroying manufactured components.Changes can be made to designs

then tested immediately.

3D Modelling – rendering

3D models can be rendered to make them look very realistic.

Materials can be applied to any part of a 3D model.

Lights can be shone onto the model to create tone, shadows and reflections.

To further enhance the look of an object you can create suitable environments to place them in.

3D Modelling – rendering

Here a pen was produced using 3D modelling software. The room, table and paper was then produced to help

enhance the look of it.

3D Modelling - commands

There are a large number of commands available to a user of 3D modelling software.

The most common commands you will use at N4 & N5 are: Extrude Revolve Round Chamfer

3D Modelling - extrude

Extruding a sketch is like stretching it in a straight line to create a solid object.

The sketch of the circle (shown below) has been extruded into a cylinder.

3D Modelling - revolve

When you want to extend or extrude an object around a radius then you would use the revolve command.

Here the sketch (shown below left) has been revolved to make a bowl.

3D Modelling - round

Rounds can be added to corners of shapes. Here the corners of the support plate have

been rounded.

3D Modelling - chamfer

Chamfers are 45° edges that are added to corners to remove the sharp corners from an object.

3D Modelling – planning

When creating a 3D model of an object it is a good idea to plan the sketches and the different types of commands you will use.

This will allow you to keep a track of all the dimensions you use throughout your model.

NOTE: you should keep your planning notes you use when producing a 3D model as they will be used when assessing your N4 or N5 coursework.

3D Modelling – planning your model

The next few slides will explain how you can plan how to create the hinge pin shown on the right.

3D Modelling – planning your model

To make a plan of how you will create your 3D model you need to manually sketch the shape you need to extrude or revolve to make the 3D object.

It is important that you add the main dimensions to this sketch.

3D Modelling – planning your model

Once you have manually sketched the shape you need, you need to say what command you will use to make it 3D.

As described earlier, some of the most commonly used commands are: Extrude Revolve Round chamfer

Any other suitable command could be used.

3D Modelling – the plan