CAD Flashcards
2D CAD
Similar to a drawing board, 2D CAD creates technical line drawings. Architecture, automotive and industrial design industries make use of 2D CAD. When saved as specific file types, 2D CAD drawings export to 2D Computer Aided Manufacture machines such as laser cutters to create models, and to drum plotters to print large engineering and architectural drawings.
Advantages of creating 2D CAD drawings over 3D CAD:
No multiple components to assemble
Fewer steps required
As the drawing is 2D (flat) there is no depth to produce.
3D CAD modelling
3D CAD modelling is now the most common form of CAD modelling. It allows designers to create complex models including buildings and products in three dimensions. 3D CAD models are often created with multiple parts assembled together and projects can be collaborated on.
Advantages of 3D CAD modelling:
Models can be manipulated to be viewed around 360 degrees
More realistic than 2D CAD
Depth is visible
Can be imported into an environment
Lighting effects can be applied to 3D models
Can enable CAD/CAM
Can be simulated and animated
3D CAD Illustration
3D CAD Illustration is the process of applying materials, highlights and shadows to a CAD model and rendering it to create a realistic looking image of the model.
Advantages of 3D CAD Illustration:
Allows the designer to apply materials, textures, light sources, shadows and reflections to graphics
Models look far more realistic
Materials can be seen
Light, shadow, reflection, and highlights can be seen
Colours are shown
Better idea of how it might look in an environment
Easier for non-graphics specialists to understand
CAD terminology
need to print
2D drawing tools
need to print
Extrude
Extrude is the most commonly used 3D modelling feature. It takes a 2D shape and pulls it into a 3D form. This can be used to add or subtract material.
Revolve
Revolve is used to create cylindrical 3D solids. This is achieved by revolving a 2D sketch around a centre axis.
Add, subtract and intersect
ADD: Creates material
SUBTRACT: Removes material from a solid
INTERSECT: Keeps the material that occurs between a solid and the extrusion
Shell
Shell is used to remove material from inside a 3D model. This creates a specific wall thickness and can be used to remove a face of the object
Fillet
Fillet rounds the edge of an object to a specific radius.
Chamfer
Chamfer creates a straight edge, usually at 45 degrees, on the edge of an object. The size and angle of this can be edited.
Mirror
Mirror allows 3D modelling edits to be mirror copied.
Array (linear, box, radial)
Need to print
Mate
Mate allows for a face on one part to be to be stuck to the face of another part in an assembly.
Align
Align allows a face on one part to line up with the face of another part.
Centre axis
Centre axis is used with cylindrical items. It uses the centre axis of both parts to ensure that they are aligned using that centre axis.
Modelling tree
A modelling tree is a hierarchal list that shows how you have created your CAD model. It is useful because it allows designers to edit sketches, dimensions or other aspects of their model without having to start again.
Pictorial views
need to print
Orthographic views
Orthographic views are a key method in the communication between designers and manufacturers. They are easy to create from a 3D model in CAD software. The software is easily able to create the elevation, end elevation and plan from a 3D CAD model, as well as a range of other views.
Creating orthographic views in CAD software is a highly accurate way of creating this type of view and allows easy editing of scale and addition of dimensions and other annotation.
The use and function of CAD libraries
CAD Libraries store common drawing parts that can be added to drawings/models as often as required eg, screws, bolts, switches, sinks.
Benefits of using a CAD library:
It saves both time and effort as you do not have to create a part multiple times.
CAD libraries can be shared among CAD technicians so, when working on a project, common parts can be used.
Components in CAD libraries are usually quality controlled and are made to a good standard.
Environments
Environments are used to achieve a more realistic look in computer aided illustrations. Products can be placed in environments that are related to the use of the real-world item.
Lighting, highlights and shadows
To make renders look life like and realistic the correct lighting is essential. Designers can manipulate CAD lighting to look like light from the sun, or from a set light source such as a spotlight. These cast highlights and shadows and shows the surface texture of the selected material.
Materials
Selecting materials is important when making illustrations in CAD. Materials are created so that CAD models can look realistic when they are rendered into Computer Aided Illustrations.
Advantages of CAD
Easy to storage and retrieve drawings and files
Easy to modify models and drawings
Using the CAD Library reduces the need to redraw repetitive elements
Drawing speed and drawing quality are improved
The layout of drawings can be standardised
Drawings can be very large and not require paper
