Section 1 Introduction to Drafting
description
Transcript of Section 1 Introduction to Drafting
Section 1Introduction to
Drafting
Chapter 4CAD Commands and Functions
Permission granted to reproduce for educational use only.3© Goodheart-Willcox Co., Inc.
Objectives
• List several general categories of commands used in popular CAD programs.
• Explain how points and objects are located using a coordinate system.
• Explain the use of linear, angular, and leader dimensioning.
• Identify and describe drawing aids.
Permission granted to reproduce for educational use only.4© Goodheart-Willcox Co., Inc.
Objectives
• Discuss the purposes of colors, linetypes, and layers.
• Explain layer naming conventions as related to CAD drawings.
• Describe 3D drawing.• Explain rendering.• Explain animation.
Permission granted to reproduce for educational use only.5© Goodheart-Willcox Co., Inc.
Types of CAD Commands
• File management• Drawing• Editing• Display control• Dimensioning
Permission granted to reproduce for educational use only.6© Goodheart-Willcox Co., Inc.
Command Entry Methods
• Pull-down menus• Toolbars• Command line• Tablet
Permission granted to reproduce for educational use only.7© Goodheart-Willcox Co., Inc.
File Management Commands
• Used to create, save, or open file.• Files may originate from scratch or
template.• Drawings should be saved every 10 to 15
minutes.
Permission granted to reproduce for educational use only.8© Goodheart-Willcox Co., Inc.
Coordinate Systems
• Used to specify point locations for objects.• Cartesian coordinate system is most
common.
Permission granted to reproduce for educational use only.9© Goodheart-Willcox Co., Inc.
Cartesian Coordinate System
• X axis and Y axis used to locate points.
• Points designated as (X,Y).
• XY drawing plane sufficient for 2D work.
Permission granted to reproduce for educational use only.10© Goodheart-Willcox Co., Inc.
Types of Coordinate Entry
• Absolute coordinates• Relative coordinates• Polar coordinates
Permission granted to reproduce for educational use only.11© Goodheart-Willcox Co., Inc.
Absolute Coordinates
• Measured from origin (0,0).
• Most basic way to locate points.
Permission granted to reproduce for educational use only.12© Goodheart-Willcox Co., Inc.
Relative Coordinates
• Used to locate point from previous point.
• Designated with @ symbol.
Permission granted to reproduce for educational use only.13© Goodheart-Willcox Co., Inc.
Polar Coordinates
• Used to locate points at relative distance and angle.
• Designated @distance<angle.
• Angles typically measured from 0 horizontal.
Permission granted to reproduce for educational use only.14© Goodheart-Willcox Co., Inc.
Three-Dimensional Coordinates
• Z axis used to define “vertical” measurement.
• Points designated as (X,Y,Z).
Permission granted to reproduce for educational use only.15© Goodheart-Willcox Co., Inc.
User Coordinate System (UCS)
• Used to establish different origin from world coordinate system.
• Commonly used with 3D drawing functions.
• Created with UCS command.
Permission granted to reproduce for educational use only.16© Goodheart-Willcox Co., Inc.
Drawing Commands
• Line• Double Line• Point• Circle• Arc
• Spline• Ellipse• Rectangle• Polygon
Permission granted to reproduce for educational use only.17© Goodheart-Willcox Co., Inc.
Line Command
• Used to draw straight lines.• Two points specified.• Coordinates entered or
picked on screen.
Permission granted to reproduce for educational use only.18© Goodheart-Willcox Co., Inc.
Double Line Command
• Used to create parallel lines.• Allows user to set
distance between lines.
Permission granted to reproduce for educational use only.19© Goodheart-Willcox Co., Inc.
Point Command
• Used to create point objects.• Helpful for construction purposes.• Visibility modes used to change display.
Permission granted to reproduce for educational use only.20© Goodheart-Willcox Co., Inc.
Circle Command
• Used to create circles based on user input.• Center and radius• Center and diameter• Three points• Two points
Permission granted to reproduce for educational use only.21© Goodheart-Willcox Co., Inc.
Arc Command
• Used to create arcs based on user input.• Three points• Start, center, end• Start, center, angle• Start, center, chord
length• Start, end, radius
Permission granted to reproduce for educational use only.22© Goodheart-Willcox Co., Inc.
Spline Command
• Provides several ways to create spline.• Picking points along
curve.• Converting existing
lines into spline.
Permission granted to reproduce for educational use only.23© Goodheart-Willcox Co., Inc.
Ellipse Command
• Used to create ellipse.• Points specified for
major and minor axes.
Permission granted to reproduce for educational use only.24© Goodheart-Willcox Co., Inc.
Rectangle Command
• Provides several methods for drawing rectangles.• Width and height• Opposite corners
Permission granted to reproduce for educational use only.25© Goodheart-Willcox Co., Inc.
Polygon Command
• Provides several options to create regular polygon.• Circumscribed• Inscribed• Side length
Permission granted to reproduce for educational use only.26© Goodheart-Willcox Co., Inc.
Text Command
• Used to create text objects.• Allows text font to be
set.• Provides justification
and rotation options.
Permission granted to reproduce for educational use only.27© Goodheart-Willcox Co., Inc.
Hatch Command
• Used to “hatch” areas in section views.• Provides selection of
standard material patterns.
• Internal areas typically picked for hatching.
Permission granted to reproduce for educational use only.28© Goodheart-Willcox Co., Inc.
Editing Commands
• Erase• Undo• Move• Copy• Mirror• Rotate
• Scale• Fillet• Chamfer• Trim• Extend• Array
Permission granted to reproduce for educational use only.29© Goodheart-Willcox Co., Inc.
Mirror Command
• Used to “mirror” objects about mirror axis.• Useful for symmetrical
features.
Permission granted to reproduce for educational use only.30© Goodheart-Willcox Co., Inc.
Fillet Command
• Used to create fillet or round.
• Creates radial curve between two selected objects.
Permission granted to reproduce for educational use only.31© Goodheart-Willcox Co., Inc.
Chamfer Command
• Used to chamfer corners.• Operation similar to
Fillet command.
Permission granted to reproduce for educational use only.32© Goodheart-Willcox Co., Inc.
Array Command
• Used to copy objects in rectangular or polar pattern.• Rows, columns, and offset specified for
rectangular array.• Number of objects, center point, and angle
specified for polar array.
Permission granted to reproduce for educational use only.33© Goodheart-Willcox Co., Inc.
Arrays
Permission granted to reproduce for educational use only.34© Goodheart-Willcox Co., Inc.
Inquiry Commands
• List• Properties• Distance• Area
Permission granted to reproduce for educational use only.35© Goodheart-Willcox Co., Inc.
List and Properties Commands
• Used to display object data.• Coordinates• Line lengths• Layer assignments• Linetype settings
Permission granted to reproduce for educational use only.36© Goodheart-Willcox Co., Inc.
Area Command
• Used to make area and perimeter calculations.• Points picked to define
enclosed area.
Permission granted to reproduce for educational use only.37© Goodheart-Willcox Co., Inc.
Display Control Commands
• Zoom• Pan• View• Redraw• Regenerate
Permission granted to reproduce for educational use only.38© Goodheart-Willcox Co., Inc.
Zoom Command
• Used to enlarge or reduce display of objects.• Does not change actual size of objects.• Allows “real time” zooming and specified
magnification factor.• Useful for “zooming in” on object details.
Permission granted to reproduce for educational use only.39© Goodheart-Willcox Co., Inc.
Pan Command
• Used to move drawing on screen.• Does not “zoom” drawing.• Helpful for large drawings with objects “off”
screen.
Permission granted to reproduce for educational use only.40© Goodheart-Willcox Co., Inc.
View Command
• Used to save current display of drawing.• Allows restoring certain display without
zooming or panning.
Permission granted to reproduce for educational use only.41© Goodheart-Willcox Co., Inc.
CAD Dimensioning
• Provides major advantage over manual drafting.
• Permits flexibility for placement of text and dimension elements.
• Types of commands relate to dimension method and content.
Permission granted to reproduce for educational use only.42© Goodheart-Willcox Co., Inc.
Dimensioning Commands
• Linear• Angular• Diameter• Radius• Leader
Permission granted to reproduce for educational use only.43© Goodheart-Willcox Co., Inc.
Drawing Aids
• Grid• Snap• Ortho
Permission granted to reproduce for educational use only.44© Goodheart-Willcox Co., Inc.
Grid
• Used to show display grid on screen.• Composed of configuration of dots.• Provides visual cue for drawing size and
spacing.
Permission granted to reproduce for educational use only.45© Goodheart-Willcox Co., Inc.
Snap
• Permits alignment of cursor with specific points on screen.
• Useful for “connecting” to endpoints, intersections, and centers.
• Provides critical tool for ensuring accuracy of point locations.
Permission granted to reproduce for educational use only.46© Goodheart-Willcox Co., Inc.
Types of Snap
• Grid snap• Object snap
Permission granted to reproduce for educational use only.47© Goodheart-Willcox Co., Inc.
Common Object Snaps
• Endpoint• Center• Midpoint• Perpendicular• Tangent• Intersection
Permission granted to reproduce for educational use only.48© Goodheart-Willcox Co., Inc.
Ortho
• Forces lines to be drawn horizontally or vertically.
• Useful when lines must be drawn “square.”• Must be deactivated to draw inclined lines.
Permission granted to reproduce for educational use only.49© Goodheart-Willcox Co., Inc.
Layers
• Similar to overlays in manual drafting.• Each object has assigned layer.• Used to control visibility of drawing
content.• Usage typically regulated by company or
industry standards.• Same naming conventions should be
followed by everyone working on project.
Permission granted to reproduce for educational use only.50© Goodheart-Willcox Co., Inc.
Display Colors
• Typically assigned to layers to identify content.
• Useful for distinguishing dimensions and text from object lines.
• Usage often dictated by layer standards.
Permission granted to reproduce for educational use only.51© Goodheart-Willcox Co., Inc.
Linetypes
• Used to follow conventions in Alphabet of Lines.
• Scale settings used to control appearance.• Assigned by layer or by object type
depending on standard practice.
Permission granted to reproduce for educational use only.52© Goodheart-Willcox Co., Inc.
Blocks
• Provide way to store drawing symbols for repeated use.
• Typically saved to symbol library.• May include attribute definitions to indicate
different sizes and types.• Used to generate schedules when created
with attributes.
Permission granted to reproduce for educational use only.53© Goodheart-Willcox Co., Inc.
Block and Attributes
Permission granted to reproduce for educational use only.54© Goodheart-Willcox Co., Inc.
3D Drawing Functions
• Used for creating realistic representations of objects.
• Available in more advanced programs.• Include analysis tools in some
manufacturing applications.
Permission granted to reproduce for educational use only.55© Goodheart-Willcox Co., Inc.
Isometric Drawing
• Shows object in 3D, but it is actually two-dimensional.
• Typically made using isometric grid and snap.
Permission granted to reproduce for educational use only.56© Goodheart-Willcox Co., Inc.
Types of 3D Modeling
• Surface modeling• Solid modeling
Permission granted to reproduce for educational use only.57© Goodheart-Willcox Co., Inc.
Surface Modeling
• Creates 3D objects by giving wireframe “skin.”
• Used for rendering and animation.• Not typically used in manufacturing
applications.
Permission granted to reproduce for educational use only.58© Goodheart-Willcox Co., Inc.
Solid Modeling
• Most realistic form of 3D modeling.• Permits testing for manufacturing purposes.• Rendering and animation functions
typically supported.
Permission granted to reproduce for educational use only.59© Goodheart-Willcox Co., Inc.
3D Viewing Functions
• Hide command• Preset isometric views• Dynamic rotation
Permission granted to reproduce for educational use only.60© Goodheart-Willcox Co., Inc.
User Coordinate Systems
• Used to establish 3D drawing planes for modeling.
• Particularly useful for models with many surfaces.
• Icon used to identify system origin and orientation of XYZ drawing axes.
Permission granted to reproduce for educational use only.61© Goodheart-Willcox Co., Inc.
User Coordinate Systems (Cont.)
Permission granted to reproduce for educational use only.62© Goodheart-Willcox Co., Inc.
3D Animation and Rendering Commands
• Material• Used to define and apply surface textures to
objects• Render
• Used to “color” the drawing• Animate
• Used to add movement to objects
Permission granted to reproduce for educational use only.63© Goodheart-Willcox Co., Inc.
Rendered Model
(Bucyrus International)
Permission granted to reproduce for educational use only.64© Goodheart-Willcox Co., Inc.
Review Questions
1. Distances, areas, and perimeters can be calculated using _____ commands.
A. editingB. drawingC. inquiryD. file management
C. inquiry
Permission granted to reproduce for educational use only.65© Goodheart-Willcox Co., Inc.
Review Questions
2. The _____ command is used to create a smooth curve through a series of points.
A. LineB. EllipseC. SplineD. Hatch
C. Spline
Permission granted to reproduce for educational use only.66© Goodheart-Willcox Co., Inc.
Review Questions
3. The _____ command is used to reverse the last command operation.
A. UndoB. EraseC. MoveD. Copy
A. Undo
Permission granted to reproduce for educational use only.67© Goodheart-Willcox Co., Inc.
Review Questions
4. The _____ command is used to create multiple copies of objects in rectangular or circular patterns.
A. ScaleB. RotateC. LayerD. Array
D. Array
Permission granted to reproduce for educational use only.68© Goodheart-Willcox Co., Inc.
Review Questions
5. The _____ command is used to enlarge or reduce the drawing display by changing the magnification factor.
A. ScaleB. ZoomC. PanD. Hatch
B. Zoom
Permission granted to reproduce for educational use only.69© Goodheart-Willcox Co., Inc.
Review Questions
6. _____ coordinates define point locations at a given distance and angle from a fixed point.
Polar
Permission granted to reproduce for educational use only.70© Goodheart-Willcox Co., Inc.
Review Questions
7. A(n) _____ dimension measures the distance from the center of an arc to a point on that arc.
radius
Permission granted to reproduce for educational use only.71© Goodheart-Willcox Co., Inc.
Review Questions
8. The _____ function allows you to align the cursor with points on screen.
A. snapB. orthoC. gridD. redraw
A. snap
Permission granted to reproduce for educational use only.72© Goodheart-Willcox Co., Inc.
Review Questions
9. A _____ is a virtual piece of paper on which objects are placed.
A. gridB. hatchC. layerD. block
C. layer
Permission granted to reproduce for educational use only.73© Goodheart-Willcox Co., Inc.
Review Questions
10. A(n) _____ is text information saved with a block.
A. layerB. hatchC. gridD. attribute
D. attribute
Permission granted to reproduce for educational use only.74© Goodheart-Willcox Co., Inc.
Review Questions
11. The _____ command is used to “color” a drawing for presentation purposes.
A. RenderB. LayerC. UCSD. Hatch
A. Render
Permission granted to reproduce for educational use only.75© Goodheart-Willcox Co., Inc.
Review Questions
12. A(n) _____ drawing is a 2D drawing that shows a 3D representation of an object.
isometric
Permission granted to reproduce for educational use only.76© Goodheart-Willcox Co., Inc.
Review Questions
13. A(n) _____ is a series of still images played sequentially at a fast rate.
animation