1. Technical Drawing
Topic E: Sketching

2. Topic E: Sketching
Purpose:
The main purpose of sketching is to convey ideas. Engineers have to use sketches to brainstorm ideas, as well as, to show others what they are working on or what should be designed. Sketches are also used to document measurements from the field before they are produced as solid models on the computer.

3. Topic E: Sketching Techniques
Sketching a line:

4. Topic E: Sketching Techniques
Sketching a square:
1. Sketch 2 parallel
vertical lines
2. Sketch 2 parallel
horizontal lines
3. Put them together

5. Topic E: Sketching Techniques
Sketching an arc:

6. Topic E: Sketching Techniques
Sketching an arc:

7. Topic E: Sketching Techniques
Sketching a circle:
1) Setup the
diameter
2) Square in the
3) Sketch
diagonals

8. Topic E: Sketching Techniques
Sketching a circle:
4) Identify triangle
centers
5) Sketch arcs

9. Topic E: Sketching Techniques
Size and proportion:
Although you have learned to draw lines and arcs, you can not communicate properly until you understand how to sketch with the correct size and proportion. Without proper size and proportion your sketch will not look right.
Size: Length, width, height, distance. How big is the object you are sketching?
Proportion: If two objects are five feet apart in real life, then those two objects must appear to be five feet apart in your sketch.

10. Topic E: Sketching Techniques
Shape & Contour:
Shape refers to the outward outlines of a form. Basic Shapes include circles, ovals, squares, rectangle, and triangles
Contour is a drawing comprised of lines that follow the contours of the edges of various components of a drawing subject and define the outlines of its forms.