This document provides information about the 2D Essentials class including test scores, the course calendar, project details, and content covered in chapters 6 and 7 such as orthographic sketching conventions, section views, and common manufactured features. It outlines techniques for visualizing and drawing complex cylindrical shapes and features like fillets, rounds, and holes. Groups practiced applying various drawing conventions. The next topics will cover orthographic sketching and common features shown in views. Homework includes reading the rest of chapter 3 and answering review questions.

1. 2D ESSENTIALS
Instructor: Laura Gerold, PE
Catalog #10614113
Class # 22784, 24113, 24136, & 24138
Class Start: January 18, 2012
Class End: May 16, 2012

2. Tests
• Class Average = 87%
• Class Scatter
• A, 90-100, 6 people
• B, 80-89, 7 people
• C, 70-79, 0 people
• D, 60-69, 2 people
• Class Problems:
• Scaling!
• Using a Protractor to Measure Angles
• Sketch means to freehand draw, Draw means to use your tools

3. Course Calendar
• Tentative Schedule for the rest of the semester:
• 3/28 – Isometric Sketches (Chapter 3)
• 4/4 – Finish Isometric Sketches, Sections Views (Chapter 7)
• 4/11 – Section Views
• 4/18 – Auxiliary Views (Chapter 8)
• 4/25 – Auxiliary Views, Dimensioning (Chapter 10)
• 5/2 – Dimensioning
• 5/9 – Review for Exam 2
• 5/16 – Exam 2

4. 2D Essentials Project
• 4/4/12 – 50% Project Plans Due. Turn in what you have
drawn so far and comments will be added to your plans
on Post-it notes. Plans at this point should include scale,
drawing border, three views. (30 points)
• 5/9/12 – Final Project Due

5. 2D Essentials Project – Scoring Guide
• Project will be scored on the following items:
• Drawing Border
• Scale
• Six Orthographic Standard Views
• Auxiliary Views
• Section Views
• Dimensions
• Neatness
• Line Types

6. Orthographic Sketching Refresher
• Build an object with your block
• Draw the necessary views
• Exchange your plan with someone not in your row
• With your new plan in hand, build the item drawn by your
classmate
• Compare items with your classmate when you have both
finished – did you recreate the item accurately?

7. 1st and 3rd Angle Projections
• 1st – Europe (except U.K.), Asia
• 3rd – United States, United Kingdom, Canada, Australia
• Extra Credit – What other countries use 1st or 3rd Angle
Projections?
• Turn in what country and your reference
• 5 extra credit points
• Due by April 11th

8. CHAPTER 6 – 2D DRAWING
REPRESENTATION

9. Why Chapter 6 – 2D Representation?
• Standard orthographic projections don’t show the
complexities of many shapes that are drawn on plans out
in the field, we are going to learn the standard
conventions of drawing some complex shapes.
• What objects did you bring to class with “Common
Manufactured Features?” What features do they have?
• Let’s learn how to draw these objects . . .

10. REMOVED VIEWS
A removed view is a complete or partial view removed to another place on the sheet
so that it is no longer in direct projection with any other view.
Removed View Using
View Indicator Arrow
Removed View Using
Viewing-Plane Line

11. Removed Views
• Use removed views when you need to move a view on a
sheet so that it does not follow the standard
arrangement.
A
Standard Arrangement
Removed View

12. NECESSARY VIEWS
One-View Drawing
What are the absolute minimum views
required to completely define an object?
Two-View Drawing
Three-View Drawing

13. PARTIAL VIEWS
A view may not need to be complete but needs to show what is necessary to clearly
describe the object. This is called a partial view and is used to save sketching
time and make the drawing less confusing to read.
OR
You can use a break line to limit the partial view…

14. Showing Enlarged Details
When adding a detail,
draw a circle
around the features
that will be included in
the detail
Place the detail view on the
sheet as you would a removed
view. Label successive details
with the word DETAIL followed
by a letter, as in DETAILA,
DETAIL B,

15. Conventional Breaks
To shorten the view of a long object, you can use break lines…
Using a break to leave out a portion of the part, but allows the scale for the ends
to be increased to show the details clearly.

16. ALIGNMENT OF VIEWS
Always draw views in the “standard” arrangement...
Because CAD makes it easy to move whole views, it is
tempting to place views where they fit on the screen or
plotted sheet and not in the standard arrangement. This
is not acceptable.
3D CAD software that generates 2D drawing views as
projections of the 3D object usually has a setting to
select from third-angle or first-angle projection. Check
your software if you are unsure which projection methods
are available.

17. VISUALIZING AND DRAWING COMPLEX
CYLINDRICAL SHAPES
Steps

18. VISUALIZING AND DRAWING
COMPLEX CYLINDRICAL SHAPES
• In this drawing, how many views are necessary?
• Which views are repetitive?
• Is the centerline required to locate the rounded top?

19. VISUALIZING AND DRAWING
COMPLEX CYLINDRICAL SHAPES
• In this drawing, how many views are necessary?
• Which views are repetitive?
• What purpose does the centerline serve on this drawing?
• How do you locate the hole on views other than the front
view?

20. VISUALIZING AND DRAWING
COMPLEX CYLINDRICAL SHAPES
• In this drawing, how many views are necessary?
• Which views are repetitive?
• How many lines are used to show the counterbore in the
side and top views?

21. VISUALIZING AND DRAWING
COMPLEX CYLINDRICAL SHAPES
• In this drawing, how many views are necessary?
• Which views show the necessary detail?
• Where do the lines for the removed portion appear in the
top and side detail?

22. CYLINDERS WHEN SLICED
Cylinders are often machined to form plane or other types of surfaces.
Normal surfaces appear true shape in the view where the line of sight is
perpendicular to the surface. In the two other views that normal surface
appears on edge. The back half remains unchanged.

23. CYLINDERS WHEN SLICED
In the diagrams below (page 207), as a group, identify which view is the “line
of sight” with the normal surface shown as a true shape and which view
shows the normal surface as an edge.

24. Plotting Curves by Hand
• Step 1: Break up the
curves into several points
and locate them in the
adjacent view
• Step 2: Project the points
along the projection lines
into the top view from the
front view. Transfer the
depth from the side view,
using the back surface as a
reference plane.
• Step 3: Draw the curve
through the points.

25. CYLINDERS AND ELLIPSES
If a cylinder is cut by an inclined plane, the inclined surface is bounded by
an ellipse. This ellipse will appear as a circle in the top view, as a straight
line in the front view, and as an ellipse in the side view.
When a circular shape is shown inclined in another view and projected into
the adjacent view it will appear as an ellipse, even though the shape is a
circle. It is not shown as a true shape in any view, but we will learn how to
draw auxiliary views to show the true shape in a couple of weeks.

26. Cylinder Group Project
• As a group, draw the necessary views of a cylindrical
shape (can use shapes that you brought, or a shape that I
give you).
• Present your drawings.

27. INTERSECTIONS AND TANGENCIES
Where a curved surface is tangent to a plane surface no line is drawn (a), but
when it intersects a plane surface (b), a definite edge is formed.
When curves join each other or planes smoothly (tangent) a line is not drawn to
show where they come together (c). If a combination of curves creates a vertical
surface (d), the vertical surface is shown as a line.

28. INTERSECTIONS AND TANGENCIES
When plane surfaces join a contoured surface, a line is shown if
they are tangent, but not shown if they intersect. (e – h) As a
group, talk through e-h. Do they make sense to you?

29. Intersections of Cylinders
When the intersection is small, its
When the intersection is larger,
curved shape is not plotted
it can be approximated by
accurately because it adds little to
drawing an arc with the radius
the sketch or drawing for the time it
the same as that of the large
takes. Instead it is shown as a
cylinder.
straight line.

30. Intersection and Tangencies Group
Project
• Draw the necessary views of an item with intersection or
tangencies. Use an item that a group member brought in
or one that I have.
• Talk through your views and show the class.
• What was difficult about drawing/visualizing this object?

31. FILLETS AND ROUNDS
A rounded interior corner is called a fillet. A rounded exterior
corner is called a round.
Rounds on a CAD Model of a
Design for a Three-Hole Punch
Fillets on a CAD Model.
(Courtesy of Douglas Wintin.)
(Courtesy of Ross Traeholt.)

32. RUNOUTS
Small curves called runouts are used to represent
fillets that connect with plane surfaces tangent to
cylinders.
Runouts from different filleted
intersections will appear
different owing to the shapes of
the horizontal intersecting
members.

33. CONVENTIONAL EDGES
There is a conventional way of showing rounded and filleted edges for
the sake of clarity. Added lines depicting rounded and filleted edges.
Rounded and filleted intersections eliminate sharp edges and can make it difficult to
present the shape clearly. Small Y shapes are used where rounded or filleted
edges meet a rough surface.

34. Fillets, Rounds, Runouts Group Project
• Select an item in your group (from your items or one of my
items) that has fillets or rounds and apply the conventions
as you draw the necessary views.
• Present your drawings
• Any problems?

35. RIGHT-HAND AND LEFT-HAND PARTS
Often, parts function in pairs of similar opposite parts, but opposite
parts can rarely be exactly alike.
On sketches and drawings a left-hand part is noted as LH, and a right-hand part as RH.

36. REVOLUTION CONVENTIONS
Regular multiview projections are sometimes awkward, confusing, or
actually misleading.
Revolutions like these are
frequently used in connection
with sectioning. Revolved
sectional views are called
aligned sections.

37. REVOLUTION CONVENTIONS
• As a group, think about items in your household, at work,
that you saw on the way to class that would be best
represented in a drawing by using revolution conventions
• Will you need to use revolution conventions on your
project?
• Report your thoughts to the group

38. Common Hole Features Shown in
Orthographic Views

39. Apply Hole Representation Conventions
to Sketches
• As a group, draw necessary views with Hole
Representation Conventions. Use my blocks, regular
blocks, one of your items.
• Present results.

40. Common Features Shown in
Orthographic Views

41. Common Features Shown in Orthographic
Views Continued…

42. Putting in all together . . .
• As a group, pick an item that has the most “common
features” on it from items brought in, something you can
find in the room, or something in my stash.
• Draw the necessary views and label the “common
features.”

43. What’s Next?
• Chapter 3 – Orthographic Sketching

44. Questions?
• On one of your sketches, answer the following two
questions:
• What was the most useful thing that you learned today?
• What do you still have questions about?

45. Homework
Finish Reading Chapter 3 (3.5 – end)
Chapter 6 Review Questions: 1, 2, 3, 4
Chapter 6 Exercises: 6.1 (1), 6.2, 6.4, 6.14