Elucidation of Computer Aided Design

Computer Aided Design is assistance of computer in engineering processes such as creation,modifications & optimization,analysis.

Computer Aided Design involves creating computer models defined by geometrical parameters which can be readily altered by changing relevant parameters. CAD systems enable designers to view objects under a wide variety of representations and to test these objects by simulating real-world conditions.

It is an integration of Mechanical and Computer technology to aid in the design process like Drafting, Die Design, Tool Design, Sheet metal,Modeling, Assembly,  analysis of products.

It is both a visual and fast process which is used by Engineers in the Mechanical, Automobile, Production, Plastic, Aeronautics field to design and develop the entire product on the computer before realy producing it.

CAD is mainly used for detailed engineering of 3D models and 2D drawings of physical components, but it is also used throughout the engineering process from conceptual design and layout of products, through strength and dynamic analysis of assemblies to definition of manufacturing methods of components.

The designed product on the computer can be tested, modified and finalize for real production.

Primitive Commands

array	Ø  To use a Rectangular array option Ø   To use a Polar array option
Rotate	Ø  To rotate an object in clock wise direction or anti clockwise direction
Trim	Ø  To use  the trim commands
Extend	Ø  To use the extend ( project/edge/undo)
Break	Ø  To use the break at a point command Ø   to use the break command Ø  to use the First-point option
Chamfer	Ø  To create a chamfer (polyline/distance/angle/trim/method)
Fillet	Ø  To draw a fillet (polyline/radius/trim)
Osnap	Ø  To access the object Snap toolbar Ø  To turn Osnap on, To change the size of the Osnap cursor box Ø   Osnap –End point ( to snap to the endpoint of a line) Ø   Osnap –snap from (to move a line, To change the angle & the length of a line) Ø  To apply the snap from option to a circle, Osnap – Midpoint ( to draw a circle about the midpoint of a line) Ø   Osnap –Intersection (To use the osnap ontersection command to define an ellipse) Ø  Osnap-apparent Intersection (To draw a circle centered about an apparent intersection) Ø  Osnap –center ( to draw a line to the center point of a circle) Ø  Osnap-Quadrant ( To draw a line to one of a circle’s quadrant point) Ø  Osnap-perpendicular ( to draw  a line perpendicular to a line) Ø  Osnap-Tangent ( to draw a line tangent to a circle) Ø  Osnap-nearest ( To draw a line from a point to the nearest selected point on an existing line)
Grips	Ø  To turn the grip function off Ø  to access the grips dialog box,
Blocks insert	Ø  To create a block Ø  To insert a block Ø  To change the scale of a block Ø  To explode a block Ø  To insert blocks at different angles
Write block	Ø  To create a wblock Ø  To verify that a wblock has been created Ø  To insert a wblock into a drawing.
layers	Ø  To create new layers Ø  To change the color & linetype of a layer Ø  To draw in different layers,To change layer Ø  To change the scale of a linetypes Ø  To use the global line type scale factor,
Match properties	Ø  To use the match properties tool Ø   To turn layers off
Attributes	Ø  To add an attribute to a block Ø  To create a new block that includes attributes Ø  To insert an existing block with attributes Ø  To edit an existing attribute Ø  To use the edit global command Ø  Title blocks with attributes,

array	Ø  To use a Rectangular array option Ø   To use a Polar array option
Rotate	Ø  To rotate an object in clock wise direction or anti clockwise direction
Trim	Ø  To use  the trim commands
Extend	Ø  To use the extend ( project/edge/undo)
Break	Ø  To use the break at a point command Ø   to use the break command Ø  to use the First-point option
Chamfer	Ø  To create a chamfer (polyline/distance/angle/trim/method)
Fillet	Ø  To draw a fillet (polyline/radius/trim)
Osnap	Ø  To access the object Snap toolbar Ø  To turn Osnap on, To change the size of the Osnap cursor box Ø   Osnap –End point ( to snap to the endpoint of a line) Ø   Osnap –snap from (to move a line, To change the angle & the length of a line) Ø  To apply the snap from option to a circle, Osnap – Midpoint ( to draw a circle about the midpoint of a line) Ø   Osnap –Intersection (To use the osnap ontersection command to define an ellipse) Ø  Osnap-apparent Intersection (To draw a circle centered about an apparent intersection) Ø  Osnap –center ( to draw a line to the center point of a circle) Ø  Osnap-Quadrant ( To draw a line to one of a circle’s quadrant point) Ø  Osnap-perpendicular ( to draw  a line perpendicular to a line) Ø  Osnap-Tangent ( to draw a line tangent to a circle) Ø  Osnap-nearest ( To draw a line from a point to the nearest selected point on an existing line)
Grips	Ø  To turn the grip function off Ø  to access the grips dialog box,
Blocks insert	Ø  To create a block Ø  To insert a block Ø  To change the scale of a block Ø  To explode a block Ø  To insert blocks at different angles
Write block	Ø  To create a wblock Ø  To verify that a wblock has been created Ø  To insert a wblock into a drawing.
layers	Ø  To create new layers Ø  To change the color & linetype of a layer Ø  To draw in different layers,To change layer Ø  To change the scale of a linetypes Ø  To use the global line type scale factor,
Match properties	Ø  To use the match properties tool Ø   To turn layers off
Attributes	Ø  To add an attribute to a block Ø  To create a new block that includes attributes Ø  To insert an existing block with attributes Ø  To edit an existing attribute Ø  To use the edit global command Ø  Title blocks with attributes,

Primitive Commands of CADD

Line commands	Ø  Randomly select points Ø  set a specific value for the snap function, Ø  select points  using the snap spacing value Ø  entre the coordinate value for the start & end points Ø  use relative inputs & specify the start point Ø   the length, the direction of line
Erase commands	Ø  Select individual lines Ø  window a group of line
Construction line	Ø  Basic /hor/ver/ang
Circle command	Ø  To draw a circle-radius Ø  To draw a circle-diameter Ø  To draw a circle 2 point Ø  to draw a circle-3point Ø  To draw a circle-Tangent tangent radius Ø  Quadrant-Sensitive application (TTR)
Circle centerlines	Ø  Redefine the dimcen system variable Ø  use the centre mark option found on the dimension toolbar
Polylines	Ø  To draw a polylines: Arc /close/halfwidth/length/width Ø  To Verify that a polyline is a single entity Ø  To draw different lines thickness.
Spline	Ø  draw a Spline: Arc /close/halfwidth/length/width, To draw different lines thickness.
Ellipse	Ø  To draw an ellipse- axis end, Ø  To draw an ellipse-Centre Ø  To draw an ellipse- arc Ø  To draw an ellipse by defining its angle of rotation about the major axis
Rectangle	Ø  By point fixing method (by point fixing through mouse) Ø   through coordinate systems (absolute ,polar, relative )
Polygen	Ø  To draw a polygon –centre point Ø   To draw a polygon-edge distance
Point	Ø  To change the shape of a point Ø  To change the size of a points Ø  Including all options
Text	Ø  To use the Dtext command Ø  To use the text tool (mtext) Ø  the multiline text editor dialog box options Ø  To change the text justification Ø  To use the Symbol option, other options
move	Ø  To move a line Ø  to move a object Ø  to move a some part of a object
copy	Ø  To draw a Single copy of a object Ø   To draw a multiple copies
offset	Ø  To offset a line Ø  To offset a object
Mirror	Ø  Mirror a line Ø  mirror a object