EGR 105 Intro to Engineering:
Fall 2014
Lecture 4: Orthographic Projections and Dwg files in SolidWorks
Topics Today:
1) Orthographic Projections and Multiview Drawing
2) Creating a Drawing file in SolidWorks
3) Editing the Title Block and Changing Drawing Properties
4) Classwork
5) Homework Assignment
EGR 105 Intro to Engineering: Lecture 4:
Multiview Drawings:
The drawings that you have created so far in this class have all been
pictorial drawings. They attempted to show the entire object using a
single projection of a 3-dimensional object on a two dimensional
medium.
Done correctly, these offer a great visualization tool, but they do so at
the cost of including distortion of angles, shapes, and lengths.
There is a better drawing method for showing exact shape and size.
The most commonly used method to communicate exact shape and size
is the method known as Multiview Drawing.
A Multiview Drawing consists of a number of orthographic projections
which show an object from several different sides or views, and taken
together, completely specify all sizes and features of the object. (This
also means that no one view shows all the information needed to
specify a unique object. Therefore, you have to develop the ability to
visualize three views together to describe the object.)
Top
View
Right
Side View
Front
View
Orthographic Projection: A two dimensional projection of an object
using parallel projection lines that run from the edges and corners of an
object out to a projection plane which is normal to the projection lines.
(You can think of this as the view that is seen by an observer who is
standing an infinite distance away from the object on the other side of a
perpendicular projection plane.)
Projection
Plane
Parallel
Projectors
Projection
Plane
Projection
Multiview Drawings extend this concept of orthographic planar
projection to include views from more than one side.
The most common views include Front View (Frontal Plane)
Top View (Horizontal Plane)
and either Right Side or Left Side View (Profile Plane)
(don't include both side views because more than one is redundant)
Multiple
Projection
Views
Top View
(Horizontal Plane)
Front View
(Frontal Plane)
Right Side View
(Profile Plane)
Compare the previous views to a Multiview which includes the Left
Side View
Top View
(Horizontal Plane)
Left Side View
(Profile Plane)
Front View
(Frontal Plane)
It's important to notice that the different views align.
Each view shows two dimensions:
Top View: Shows Width and Depth
Front View: Shows Height and Width
Side View: Shows Depth and Height
The multiview drawings shown up to this point have all been classified
as 3rd Angle Projection. These views result when the projection plane is
placed above and in front of the object to be drawn. This is the standard
used in the U.S.
SI
3rd Angle Projection Symbol
SI
1st Angle Projection Symbol
If the object is instead placed in front of and above the projection
planes, this is referred to as 1st Angle Projection. This is the standard
used for drawings in Europe.
Multiple
Projection
Views
Right Side View
What is a common effect
of using a 1st angle
projection drawing
as a 3rd angle projection
drawing?
Front View
Top View
You may end up with a left handed part.
Line Types in Multiview Drawings:
Visible Lines: Thick, dark solid lines used to show the location of
edges, planes in edge views, and curved surfaces which turn normal to
the projection plane which are visible from the projection plane view.
Hidden Lines: Thin, dark dashed lines (approximately
1
8
" to
1
4
" long
separated with 132 " to 116 " gaps) used to show edges, planes in edge
view, and curved surfaces where they turn normal to the projection
plane, but are not visible in the projected view because they fall behind
other solid features of the object.
Center Lines: Thin, dark lines that consist of alternating short and
long dashes. They are used to show axes of circular or symmetrical
features and paths of motion. These lines usually extend out past the
feature associated with the axis by 1 4 " to 3 8 ".
Order of Importance: On some drawings Visible, Hidden, and Center
lines will all occur at exactly the same location. If this happens draw
only the line of highest precedence.
Highest
to
Lowest
Visible Line
↓
Hidden Line
↓
Center Line
Alphabet of Line Types:
(Copied from Engineering Graphics by Giesecke, Mitchell, Spencer, Hill, Loving, Dygdon, and Novak.)
Some Do's and Don't of Center Lines:
When an axis is seen as a point, two center lines are used and cross with
the short dashes intersecting at the axis.
When an axis is seen from the side, a single center line is used.
Examples:
Copied from Techical Graphics Communications by Bertoline, Wiebe, Miller, and Mohler.
Multiview Example:
Draw the Front, Top, and Right Side View of the object.
Front View
How would this change if we cut some additional features into this
object?
-- back cutout
-- reorientation of tri. prism
-- oblique surface
-- cylindrical hole
The Multiview would look like that below:
B
A
C
Notice the following characteristics:
Plane A is called a normal plane. How does it show up in the three
different views? _______________________________________
Plane B is called an inclined plane. How does it show up in the three
different views? ________________________________________
Plane C is called an oblique plane. How does it show up in the three
views? ________________________________________________
How does the cylindrical hole show up in the three views?
______________________________________________________
Note the center lines used to show the axis of the hole.
Multiview Drawing in SolidWorks
Creating a multiview drawing in Solid Works is almost too easy.
You start by constructing a regular 3-dimensional part file (.SLDPRT).
Using the completed part file, you then create a drawing file (.SLSDWG).
A drawing file will bring together a number of orthographic and/or
perspective views of the model. It can also be used for auxiliary views,
sectional views, dimensioning, material lists, and other details that are
to be given with the drawing. This is the file that will contain all the
detail that is to be passed on to the workers who will be manufacturing
the part or assembly.
Demo 4.1:
Create a multiview of the object below as a SolidWorks part file.
A .sldprt file of this part has been sent to your email account. You may
save it and open it if you wish to follow along with the steps.
1) Open up the part file:
2) Create a new .dwg file using the File…Make Drawing from Part
command.
3) Select your choice of layout sheet (select B-Landscape for drawings
in this class unless instructed otherwise).
4) Right click on the layout background and check the drawing
properties. Make sure the Type of Projection is Third Angle.
(The default setting may be First Angle, so you may need to correct
this…next week we will set the default using a drawing template).
5) Select the View Layout Tab, and create a view of the Standard 3
Views (Front, Top, and Right Side).
If the views are not quite what you had in mind, use the Drawing View
box near the left of the screen to modify the view. You can change line
appearance, scale, shading, and other aspects from this box. You can
also drag the views around on the screen if they need better placement.
5) Use the Projected View tool to add an isometric to the drawing.
Change its scale to 1/2 size of the other views and turn off all hidden
lines in the isometric view.
6) Select the Annotation tab and add centerlines and centermarks
where appropriate. You will usually have to drag them to the proper
length once they've been added, because they usually not the correct
length as inserted.
7) Right click the background sheet and select Edit Sheet Format to
allow you to add information to the Layout Sheet. You may want to
zoom in and use the Note tool under the Annotation tab to add new
information to the Layout Sheet.
You will be expected to add information including your name, the name
of the class, and the title of the drawing to the title block.
When complete simply return to the drawing
mode by Right clicking the background and
click the Edit Sheet command.
While there are many more features you will
learn to add to a drawing that's all we'll cover
for now, so you would then normally save and
print your completed drawing at this point.
Classwork:
CW 4.1: Create a Solid Model from the Principal Views and then make a drawing
showing these three views and the isometric view. Make sure any hidden lines are
shown on the front, top, and side views. Hidden lines should be suppressed on the
isometric view. Units are in inches.
CW 4.2—Create a solid model of the same model used in HW 2.1 and create a Csize drawing of it showing the three principal views and
an isometric view of this object. Use a scale where
1 isoblock = 20 mm. Make the five sided face shown to the
left-front in the figure (and shown in the right margin of this page)
the front view of your drawing. Fill in the title block with your name,
the date and a title. Once again make sure you show hidden lines in the front, top,
and side view. Do not show hidden lines in the isometric view.
CW 4.3: Using a straight edge, draw in the missing lines and views of these multiviews
Homework:
HW 4.1-- Using Solid Works, create a solid model of the object shown in Figure
HW4.1 below. Use a scale of 1 block = 10 mm. Make a B-size drawing of four
views of this object (front, right, horizontal, and isometric). Type your name
and HW4.1 in the title block. Show hidden and center lines in the top, front, and
right side view. Do not show hidden lines, center lines in the isometric view. If
possible, also turn off tangency lines. (hint: Right mouse click the view to find
the tangency on/off toggle switch)
HW 4.2 -- Using Solid Works, create a revolved 180o extrusion about the x-axis
of the area shown in figure HW 4.2 below. Use a scale of 1 block = 10 mm.
Make a B-size drawing of only the isometric view of the object. Fill in the title
block information including your name and HW4.2
HW 4.3: Work through the Detail Drawing tutorial in your Beginner's Guide for
Drawing One: the Housing which starts on page 243 of the 2013 Beginner’s
Guide to Solid Works . Fit the drawing to a B size landscape title block. Fill in
your name and the title HW4.3 to the title block.
HW 4.1
HW 4.2