Pictorials in AutoCADPictorials in AutoCAD
Class 8.2 : Using AutoCAD to Create Pictorial Drawings
Readiness Assessment Test 8.2.1
Individually take 3 minutes and respond to the following question:
What dimensions are contained on each of the principal projection planes?
Learning Objectives
Use AutoCAD to draw an oblique of an object given orthographic views of the object
Select the best orientation of an object in pictorial Define what makes a drawing a: cavalier oblique,
cabinet oblique, general oblique, isometric, axonometric, perspective, or orthographic views
Sketch pictorials of an object (either oblique or isometric) given orthographic views of the object
Use AutoCAD to generate Isometric Drawings of objects given the orthographic views of the object.
TypesTypes
Obliques– Cavalier– Cabinet
Axonometrics– Isometrics– Others
Perspectives
Cavalier Oblique
Front view true size Receding Axis Angle
(Normally 30°, 45° or 60°) is Variable
Depth dimension (receding axis) true size
Cabinet Oblique
Front view true size Receding Axis Angle
(Normally 30°, 45° or 60°) is Variable
Depth dimension (receding axis) half size
General Oblique
Front view true size Receding Axis Angle
(Normally 30°, 45° or 60°) is Variable
Depth dimension (receding axis) between half and full size
Angles in Oblique
Angles in front view are drawn true size Other angles must be located using coordinates Appearance of angles may be distorted
Obliques
Obliques are theoretical drawings. In reality, you can not actually view an object as an Oblique
Thin parts look very good as Obliques Parts with angular features on multiple
planes are difficult to draw as Obliques
Circles in Oblique
Drawn true size in front view Drawn as ellipses on receding planes Layout using a Rhombus
Today’s AutoCAD commands
Drawing setup– Drawing Aids
Display control– ZOOM
General Concepts– Keyboard Coordinates
Editing and inquiry– MOVE– COPY– TRIM
Object Snap– ENDPoint– TANgent– NEArest
Drawing Obliques in AutoCAD
Initially you should make a rough sketch of the object to get an idea of what your drawing should look like
Draw the front view as a flat orthographic view Use the COPY command along with keyboard coordinates
to place the front view along the receding axis to represent all frontal surfaces in the object
Connect the copies with lines representing the depth of the object. Remember to use OSNAP to assist in this process
Use ERASE and TRIM as appropriate to remove unwanted lines/arcs
Example
Example
Construction of an oblique
Draw the front view using normal AutoCAD commands and techniques
Construction of an oblique Use the COPY command to
replicate the front view to depict the depth
Command: COPYESelect objects: [Other corner:[ 11 found
Select objects:E<Base point or displacement>/Multiple: mEBase point: [Second point of displacement: @.8<40ESecond point of displacement: @1.8<40ESecond point of displacement:E
Construction of an oblique
ERASE the portions of the depth profiles which will not be seen.Command: eraseESelect objects:[Select objects:[…
Select objects: [Select objects: E
Construction of an oblique
Add receding lines using OSNAP and the LINE command.Command: lineEFrom Point: endpE of[To Point: endpE of[To Point:E…
Construction of an oblique
TRIM and ERASE the remaining lines which would not be visible.
Command: TRIMESelect cutting edges: (Projmode = UCS,
Edgemode = No extend)
Select objects: [1 found
Select objects:E<Select object to Trim>/Project/Edge/Undo:[<Select object to trim>/Project/Edge/Undo:E
Exercise 8.2.1
Isometrics
Axes equally separated (120°)
H, W, and D measurements are true size along iso. axes
Angles must be located by coordinates
Circles appear as ellipses on all surfaces
Drawing Isometrics in AutoCAD
Initially you should do a rough sketch of the object by hand to get an idea of what your drawing should look like
Switch the crosshairs to isometric mode Draw the object using the LINE and ELLIPSE commands Use F5 to toggle the current isometric plane Use OTRHO and OSNAP to assist you in the drawing TRIM or ERASE any portions which are not visible
Using isometric snap
If the crosshairs are not set in isometric mode, use the Drafting Settings dialog box.– Right click on
snap button and choose settings
Drawing Ellipses
In isometrics, circular features which lie on the principal planes are shown as ellipses
These MUST be drawn using the ELLIPSE command with the Isocircle option
Command: ellipseEArc/Center/Isocircle/<Axis endpoint 1>: iECenter of circle:[<Circle radius>/Diameter:[
Pair Exercise
Draw an Isometric pictorial of the object shown on the next slide using AutoCAD.
The grid is a .2” grid Use template E38c.dwt Erase the “Robot Foot” Include centerlines at the discretion of your
instructor
Isometric Example
Think-Pair-Share
In the next 1 minute as an Individual if I only answer one question . . . specifically what don’t
you understand about pictorials [at least 3 things] Now take 2 minutes to merge your list with the person sitting next to you AND
add 1 new item to the list In the next 5 minutes share the results with the other half of your team, delete
questions that you can answer for each other, AND prioritize the remaining questions your list
Paired Homework
Top Related