Sketching and Technical Drawing Foundations of Technology Sketching and Technical Drawing © 2013 International Technology and Engineering Educators Association

Foundations of Technology

Sketching and Technical DrawingSketching and Technical Drawing

© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Foundations of Technology

Teacher Resource – Unit 2 Lesson 5

The BIG IdeaThe BIG Idea

Big Idea:

At various intervals of the Engineering Design Process, conceptual, mathematical, and physical models are used to evaluate the design solution.


Annotated SketchesAnnotated Sketches

Annotated Sketches are sketches that include notes or labels, dimensions, and/or symbols.

Sketches are often used to show an idea or visibly capture a thought.

All sketches should includesome type of annotation.


Annotated SketchesAnnotated Sketches

Sketching takes practice, but there are some basics to remember:

Use long, light, and flowing lines rather than heavy or short lines.

Sketches are a loose representation of the idea; accuracy is not critical.

Keep your sketches quick; include enough detail to get your idea across.

Use basic shapes to frame the sketch, then add more detail.


Technical DrawingsTechnical Drawings

Technical drawing is a visual communication language that is used to communicate how something works or is constructed.

All technical drawings include:

Standard symbols

Units of measurement



Technical Drawings can be produced using paper and pencil or on a computer using computer-aided design (CAD).

We will use two basics types oftechnical drawings:

Orthographic projection

Isometric projection



Orthographic projection is a way to represent a three-dimensional object in two dimensions.

Typically, two or more elevations or pictures areproduced to represent the entire object—known as multiview projection.



Orthographic projection typically displays the top, front, and ride side views of a three-dimensional object.


Top (yellow)

Front (grey)

RightSide

(green)

Top

RightSide

Front

Multiview Projection


Orthographic multiview projection has some basic terminology:


Top Elevation

Side ElevationFront Elevation

Construction Lines (light)

Part Outline(solid)

Hidden Lines (dashed)

Dimensions(singular or

stacked)


Drawing orthographically will take practice, but there are some basics to remember:

Use construction lines toframe out the work space.

The distance between elevations are equal.

Use construction lines to project details betweenthe elevations.


Construction Lines

Equal

Top

Side

Front


Drawing orthographically will take practice, but there are some basics to remember:

A 45°-angle line can be drawn to help project between the top and sideelevation.

Darken the lines thatrepresent the part.

Do not erase constructionlines.


45° Construction Line

Top

Side

Front

Finished Lines

(darkened)

Construction Lines (light)


Orthographic Drawing Practice


2

2

5

44

1. Establish an Origin (staring point)

2. Frame out the work space with Construction

Lines – total height, width and depth, leaving

equal space between objects

Depth = 4

Height = 5

Width = 4 Depth = 4

3. Project the outline of the top, front and side

views using Construction Lines

Top

Front

Side

5. Add points of interest to the most

descriptive view

4. Add a 45° line starting in the upper right hand corner –

used to project details between the top and side views

6. Project points of interest using

Construction Lines

7. Darken all finished lines for each view


Isometric projection is a simple way to show a three-dimensional object.

By using isometric projection, three sides of an object areshown proportionally.

All vertical lines are drawn vertically, and all horizontal lines are drawn at an angle of 30° degrees.



Drawing isometrically will take practice, but there are some basics to remember:

Use construction lines toframe out the work space.

Use construction lines to project details on surfaces.

Use accurate measurements on all surfaces.



Isometric Drawing Practice


2

2

5

44

1. Establish and origin

(starting point)

2. Frame out the work space with

Construction Lines – total height, width

and depth

Height = 5

Width= 4Depth

= 4

3. Add points of interest to the

most descriptive view(s)

4. Project points of interest using

Construction Lines

5. Additional points of interest can now

be identified – project those points using Construction

Lines

6. Darken all finished lines

Documents

Sketching and Technical Drawing Foundations of Technology Sketching and Technical Drawing © 2013 International Technology and Engineering Educators Association