Technological Drawings 1 Sketch vs Diagram vs Drawing

Technological Drawings

1. Sketch vs. Diagram vs. Drawing

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

2. Basic lines

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

What is the difference?

What is the difference?

3. Types of Projections

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

Projections Ø Orthogonal l Isometric • All three sides are shown

Projections Ø Orthogonal l Multiview • Shows all three sides with details

Projections Ø Axonometric l l l 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 Ø Reduction Scale l l Ø Enlargement Scale l l Ø 1: 2 1 mm in the drawing represents 2 mm in real life 2: 1 2 mm in the drawing represents 1 mm in real life Actual size representation l l 1: 1 Object is life size

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

5. Cross-Sections and Sections

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

Cross-Section

Sections Ø Revolved Section Ø Removed Section