1. Sketching Techniques Sketching Techniques Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Sketching Techniques

2. Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Purposes of Sketching
Think through a design – look at it instead of just thinking about it
Communicate your ideas – let others look at what you are thinking
Uses lines and symbols to describe a design – it takes a lot of words to describe even a simple shape
There are several purposes for creating sketches. Sketches help you to think through a design. They also help you convey your ideas to other people for better understanding. Sketching is a language just like any other. The difference is that in sketching we use lines and symbols to describe the shape, size, and even the function of a design.
Draw a 3” horizontal line
Draw a 3” line extending from one end of the horizontal line at 45 degrees
Connect the ends of the two lines with a third line

3. Common Uses of Sketching
Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Common Uses of Sketching
Brainstorming ideas
Piggy backing on variations
Communicate
Pass on information
Document Dimensions
Size of surfaces and features
In the engineering field, sketches are often used to brainstorm ideas and to solve problems. Many times they are used to communicate ideas to other people for better understanding or explanation of an object. Sketches are also used to document measurements taken in the field to be used back at the office.

4. Advantages of Sketching
Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Advantages of Sketching
Convenient
Inexpensive
How many words would it take you to describe this pair of pulleys?
Creating and using sketches provides several advantages. Sketches are convenient and can be created almost anywhere, plus they are inexpensive. Few additional materials are needed. Only pencil and paper is required to create a sketch.
There would be a lot of assumptions and prior knowledge necessary for someone to be able to draw this from a verbal description

5. Sketching Techniques #1
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Sketching Techniques #1
Sketching a Line 1) 2)
When sketching a line, first, plot the start and end points. Next, draw short line segments between the two points so that you have an idea of where the line will be drawn. Finally, darken the smaller lines so that one solid line appears between the two points. You will repeat the same process when drawing vertical or inclined lines. 3)

6. Sketching Techniques #1
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Sketching Techniques #1
Lines (if you didn’t have graph paper)
Inclined Line
Run
Rise
Vertical Line
Horizontal Line
There are some skills that we need to discuss, such as vertical lines, horizontal lines, plus inclined or slanted lines. To create any of the lines shown, it is important to plot or locate two points, the start and end points, before you attempt to draw the line.

7. Sketching Techniques #1
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Sketching Techniques #1
Sketching a Circle in 5 steps
The lines in steps 1 – 5 should be thin and light
(barely visible) “Construction Lines”
1) Set up the
diameter
2) Square in the
diameter
3) Sketch
diagonals
To sketch a circle, you will complete a five step process. In step one, create a horizontal and vertical line the size of the desired diameter of the circle. Make sure the two lines intersect each other at the midpoints of the lines. For step two, sketch a square the size of the desired diameter. Make all horizontal and vertical lines the same length to ensure a true square shape. In step three, create diagonal or slanted lines connecting the four original diameter size marks together.

8. Sketching Techniques #1
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Sketching Techniques #1
Sketching a Circle
The lines in steps 1 – 5 should be thin and light
(barely visible) “Construction Lines”
4) Identify triangle
centers
5) Sketch arcs
Now in step four, create a mark at the center location for each of the triangles. In the last step, sketch curved lines using the original diameter marks and the center marks just created to complete a perfect circle.

9. Alphabet of Lines #2 Construction Object Hidden Center
Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Alphabet of Lines #2
Construction
Object
Hidden
Center
There are four main types of lines used when creating sketches. In the following slides, you will be shown each type of line and where it is used on a sketch.

10. Alphabet of Lines Construction Line Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Alphabet of Lines
Construction Line
Construction lines are lightly drawn lines used as guides to help all other lines and shapes to be drawn properly. If you hold your paper an arm’s length away, you should not be able to see construction lines. They can even be erased after the object is sketched.

11. Alphabet of Lines Object Line Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Alphabet of Lines
Object Line
Object lines are thick lines used to show visible edges of an object. In many situations, construction lines turn into object.

12. Alphabet of Lines Hidden Line Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Alphabet of Lines
Hidden Line
Hidden lines are used to show interior details not visible from the outside of the object being drawn. In this part a hidden line is used to show a hole not visible from this side of the object.

13. Alphabet of Lines Center Line Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Alphabet of Lines
Center Line
Center lines are used to define the center of the arcs, circles, or symmetrical parts. They are drawn half as thick as object lines. In this example the center line is used to define or show the center of the hole in the object.

14. Sketching Techniques
Gateway To Technology®
Unit 1 – Lesson 1.4 – Sketching and Dimensioning Techniques
Image Resources
Microsoft, Inc. (2008). Clip Art. Retrieved October 20, 2008, from