COMPUTER- AIDED DRAFTING (CAD)

DRAFTING The process of representing three- dimensional objects in two-dimensions. The language of industry.

CAD ADVANTAGES Faster More accurate Neater

CAD SYSTEM COMPONENTS

HARDWARE Fast, powerful computer Input devices Monitor Plotters

SOFTWARE CAD programs – some are easy to use, others are difficult to use. Make sure that it has all the features you’ll need. Make sure that it’ll work with your hardware.

CARTESIAN COORDINATE SYSTEM

A system that allows you to plot points on a drawing. Based on an imaginary grid.

X axis plots width Y axis plots height Z axis shows depth on 3D drawings

Origin : point where X and Y axes meet (=0) Coordinate pair : set of two numbers that locate a point on the grid (X,Y)

TWO-DIMENSIONAL AND THREE-DIMENSIONAL CAD DRAWINGS

2D DRAWINGS width and length; width and height; or length and height

3D DRAWINGS Add depth (Z axis) to a 2D drawing

Wireframe drawings : look like wire sculptures.

Surface models: show solids instead of just lines

Solid models : so realistic that they resemble a photograph or the work of a skilled artist.

CATEGORIES OF CAD COMMANDS

DRAWING Used to create lines, circles, and other geometric shapes. (object/entity) – LINE – CIRCLE – ARC – TEXT – DIMENSIONING

EDITING Used to make changes on drawings. – ERASE – MOVE – COPY – ROTATE – MIRROR

UTILITY ZOOM PLAN PLOT