Orthographics in AutoCAD
Class 3.2: Multi-view Drawings
Readiness Assessment Test 3.2.1
• As a team, respond to the following
question. You will be given 2 minutes:
• Name the six principal orthographic views.
Learning Objectives
• Name the three principle projection planes
and the dimensions that each one shows
• Use AutoCAD to create orthographic views
of objects
• Know the correct line weights for printing
drawings from AutoCAD
Orthographic Projection
• 2 Dimensional projections on Orthogonal
planes
• Show lines based on change of plane or
change of material
• Use multiple linetypes
– Visible
– Hidden
– Center
Describing a “Step Wedge”
• A relatively simple
object
• Pictorial view may be
difficult
Glass Box Concept
• Envision the object
surrounded by a glass
box
• Project the views out
onto the glass panes
• Each pane shows a 2D
projection of the
object
Projection Planes
• The three panes of glass represent the
principal orthographic planes
– Horizontal
– Frontal
– Profile
• Each plane illustrates two of the principal
dimensions of:
HEIGHT, WIDTH or DEPTH
Readiness Assessment Test 3.2.2
• Individually respond to the following
question. You will be given 1 minute:
• Name the six principal orthographic views
and the dimensions each shows.
Class Exercise
• As a team you have 3 minutes to discuss the
following:
• What dimensions are contained on each of
the principal projection planes?
Converting to Orthographics
• By unfolding the box,
you generate the
FRONT, TOP, and
RIGHT SIDE views
• Others (Back, Bottom,
Left Side) could also
be created if needed
Completed Orthographics
Choice of Orthographic Views
• If the object has an obvious top, then it must
be the top view
• Minimize the number of hidden lines
• Use the most descriptive view as the front
view
• Conserve space by choosing the depth to be
the smallest dimension
Linetypes
•
•
•
•
Visible (0.6 mm)
Hidden (0.3 mm)
Center (0.3 mm)
Construction (0)
Precedence of Lines
• When lines coincide
with each other, the
more important lines
take precedence over
the other lines. The
order of precedence is:
– Visible
– Hidden
– Center
Paired Exercise
• Sketch three orthographic views of the
object shown on the next slide.
• Include visible, hidden, and centerlines
where appropriate.
• Use the grid paper from the back of your
workbook or your engineering sketch pad.
Object for Exercise
AutoCAD commands Review
• Drawing setup
– SNAP
– GRID
• Display control
– ZOOM
– PAN
• Drawing
–
–
–
–
LINE
DTEXT
CIRCLE
ARC
• Editing and inquiry
–
–
–
–
–
–
–
ERASE
DDEDIT
TRIM
FILLET
UNDO
Modify properties
Grips
• General Concepts
– Layers
– Ortho Mode
Entering AutoCAD
• Log on to the network
• Double click on
AutoCAD icon
• Select Use a Template
– Find drawing template
E09C.dwt
– Select OK
Status line at the bottom
• The status line at the bottom of the display tells you
whether any of the modes are on or off.
• The “pressed” modes are on. (SNAP, GRID, ORTHO and
MODEL in the picture below)
• These are saved with the computer, so if your drawing
does not have the correct modes selected, please modify
the choices as shown below.
Working with Layers
• Layers are used to
control the type of line
that will be drawn
• They are pre-defined
on the templates used
for this class
• They are accessed
from a dropdown list
as shown to the right
Display Control
• ZOOM -- scales the screen view to an area
of the drawing surface
– “Window” will zoom down to a window
– “All” will zoom out to show the larger of the
drawn entities or limits
– Realtime allows you to shrink or enlarge the
display in real time.
• PAN -- moves around on the drawing
surface
Drawing Objects
• Drawing commands are found on the
toolbar located at the left of the screen
• The four of interest today are Line,
Arc, Circle, and Mtext
• These may be abbreviated from the
keyboard using the first letter(s) (e.g.)
–
–
–
–
Line
Arc
Circle
Line - L
Arc - A
Circle - C
Mtext - MT
Mtext
Completing the Title Strip
• Rather than using the MTEXT command to compete the
title block, it is simpler to edit the existing text.
• The command to do this is DDEDIT, or find “Text…”
under the Modify pulldown menu.
• Or you can double click on the text to be edited.
Formats of Keyboard Coordinates
• Either absolute or relative
– Absolute -- references origin of drawing (0,0)
– Relative -- references previously selected point
• Absolute is the default
• Precede relative coordinates with an @ sign
– @10,20 or @ 10<45
• Direct Distance
– Enter a distance in the direction of the cursor and return
Paired Exercise
• Start a new drawing.
• Use template E09c.dwt
• You have 15 minutes to complete as many
of the drawings as possible
• Save your solutions on a floppy disk.
Printing in AutoCAD
• Printing is done via
the PLOT command
• Always plot limits
• Set origin to “Center
the Plot”
• Always plot at a
scale appropriate to
the drawing
(normally 1:1)
• ALWAYS GET A
FULL PREVIEW
BEFORE
PRINTING
Plot Device Settings
• Under Plot
Device, make
sure the printer
is selected and
the Plot Style
Table is set to
“endg105.ctb”.
• Select the
printer for the
room you are in.
Homework