Technological Drawings

1. Sketch vs. Diagram vs. Drawing

Sketch vs. diagram vs. drawing Sketch : quick free hand drawing Diagram: (how the object is made) Drawing: (how the object looks)

2. Basic lines

Basic Lines Visible Contour Line Hidden Contour Line Center Line Extension Line Dimension Line

What is the difference?

What is the difference?

3. Types of Projections

Projections Oblique 1 face is parallel to the paper Depth is altered

Projections Orthogonal Isometric All three sides are shown

Projections Top Front Side Orthogonal Multiview Shows all three sides with details Top Front Side

Projections Axonometric Shows in details all parts of an object Also called the exploded view Comes with a list of parts (nomenclature)

4. Scales

What is it?

What is it?

Purpose of scales Reduction Scale Enlargement Scale 1:2 1 mm in the drawing represents 2 mm in real life Enlargement Scale 2:1 2 mm in the drawing represents 1 mm in real life Actual size representation 1:1 Object is life size

Scale What scale would you use to draw a … Train Spider A parc statue A pencil

5. Cross-Sections and Sections

Cross-sections vs Section Shows the interior details of an object as if it were cut by a cutting plane Sections: Shows the interior details of a part of an object as if it were but by a cutting plane

Cross-Section

Sections Revolved Section Removed Section