DRAFTING

Terms in this set (44)

Computer Aided Drafting

Computer Aided Design

Reasons to use CAD

Can reduce drawing time and improves productivity
Prevents having to make repeated drawings of often used symbols
Improves overall appearance and readability of drawing
Allows for easy revision of drawings
Can be transmitted electronically
3D models, as a 3D database

Allows you to select coordinate and angle display formats and precision

Controls the imaginary boundaries of the drawing.
Should correspond to the drawing sheet size you choose.

Forces every line drawn to be either horizontal or vertical.

similar to a transparent paper overlay
C: Color
L: Line Type

enters exact distance and angles for lines

polyline enters a single line with multiple points seen as a single line

creates me a circle default is center point and radius

Used to create an arc of any size.
The default is to pick 3 points along the arc, two of the points being the end points.

creates a polygon

Allows you to create ellipses of any size by defining the axes.

The TEXT command is only useful when creating one line of text.
MTEXT creates multiple lines of text and allows you to choose your font.

perpendicular lines
Used to create a perpendicular line to a given line.

Parallel lines
Offset allows you to copy a given line a specific distance away.

Use tangent object snap to create tangent lines.

E: Extents makes the farthest edges of the actual drawing fill up the screen.
A: All fills the limits of the drawing to the screen. (Can also use LIMITS.)
W: Window has you pick the lower left corner and the upper right corner you wish to zoom.
D: Dynamic makes an adjustable lens appear on the screen, capable of being moved to different parts of the drawing.
P: Previous zooms back to the previous zoom.

regenerate
Forces synchronization of the drawing file and the screen display.

Dimension options

Dimension
Linear dimensions:
ALIGNED: For dimensions parallel to the object.
HORIZONTAL: For horizontal dimension lines.
VERTICAL: For vertical dimension lines.
Angular dimensions:
ANGULAR: Creates and arc and labels the angle between two lines.
Circles
DIAMETER: Draws a dimension line through the center.
Arcs
RADIUS: Draws the radius dimension.
Center line or mark
CENTER: Draws a pair of cross lines at the center of a circle or arc.
Leader lines
LEADER: Draws a line with an arrow head, and prompts for a note at the end of the line.

pattern filling

groups one or more objects

divides an object into a certain number of parts

reflects stuff across a choosen axis

alters the size of a object
R: Resizes with respect to a reference size

freehand drawing

Makes multiple copies of selected objects in a rectangular or circular pattern.
Options Include:
R: Rectangular array
P: Polar array creates a circular pattern

selects objects
Groups objects into selection sets.
Options Include:
W: Window selection allows you to create a rectangle that should COMPLETELY enclose all items that should be selected.
C: Window crossing allows you to create a rectangle that will select anything inside or touching the rectangle.
WP and CP work the same as the window, but with a polygon.
F: Fence allows you to create a polyline that you can draw through objects. Anything touching the fence is selected.
ALL: Selects all objects.
L: Selects the last object created.
P: Selects the last selection you defined.
R: Removes objects from the current selection set.
A: Adds objects to the current selection set.

COPY, ERASE, MOVE (m),UNDO

copy erase and moves, UNDO s

change prosperitys
Allows you to change an elements color, layer, linetype, and thickness.

object into separate entitys

Polyline edit
Allows you to modify polylines which are already drawn.
Options Include:
C: Closes an open polyline
E: Edits verticesJ: Joins a line or arc to a
F: Fits a curve to a polyline
polyline
O: Opens a closed polyline

2d point entrys

Cartesian or Rectangular Coordinates
Absolute Coordinates (X,Y): Specifies a point's exact distance from the origin point.
Relative Method (@X,Y): Specifies a point's exact distance from the last point that was entered.
Polar Coordinates (@Distance<Angle)
Specifies a point's exact location by a distance and angle from the last point that was entered.
Direct Distance
By pointing the cursor in the direction of the next line you can enter the length of that line. This works with the polyline command.

Wireframe Models
Surface Models
Solid Models

3d modeling systems

wireframe no fill

surfaces define the shape of a hallow model

solid primitives

Box or Rectangular Prism
Wedge or Triangular Prism
Cone
Cylinder
ect

Boolean Commands

Union: Adds parts together
Subtract or Difference: Removes parts or features
Intersection: Intersects overlapping volumes into a single feature

Extrude creates a feature by extruding a 3D object from a 2D sketch, essentially adding dimension.

Hide: hides edges that are not visible
Shade: a flat coloring system that takes minimum lighting into account.
Render: allows for more realistic and complex surfaces.
Includes sophisticated lighting and shadows
Includes texture and bump maps
Includes sophisticated backgrounds
Raytracing generates reflections, refraction and more precise shadows.

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