Technical DrawingVisual Communication of Technical Information

Technical DrawingVisual Communication of Technical Information

Unit Overview – 5 to 10 classes Precise Drawings Give More

Information Types of Technical Drawing

Isometric Projections Parallel, Perspective, and Oblique Orthographic Projections

Multi-view Sketches Practice

Tech Drawing -- Overview

Good drawings convey detailed information about solutions to technical problems. In this unit you will learn:

Technical Drawing (focus of two types)

Puzzle cube design and fabrication Orthographic and Isometric Layouts

Manufacturing diagrams

How can we present an object and learn the most about it?

This view shows a square object with a number and some other detail

This view shows two sides and more information. Note: All vertical lines are parallel

Isometric Projection

This view shows three sides and even more information. All vertical lines are parallel; all other lines are 30 to 60 degrees above the horizon.

Isometric Projection

A see-through version lets us infer information about the hidden sides

Isometric Projection

Oblique Projection

The front is drawn on the X and Y axes. The side and top are drawn at an oblique (not square) angle in the Z direction. A lot of information is shown regarding the front; less about the top and side.

Parallel Projection

Parallel lines remain parallel regardless of how they really appear

Perspective Projection

Parallel lines meet in the distance as they really appear

Perspective and Parallel

The cube is scaled to be 12 ft.

How can we make a standard drawing of this object?

To begin:

Horizon

All vertical lines are perpendicular to the horizon

Next:

Horizon

All other lines rise at 30 degrees from the horizon

Continue:

Horizon

All lines that complete the diagram are parallel to one of the three main lines

Complete:

Horizon

The final isometric drawing presents three sides and infers information about the other sides

Practice

Take a few minutes to copy EACH of these isometric figures in your notebook or on plain paper

1.

2.

Start with each of the three isometric axes

Add vertical lines from the corners. They should be parallel to the center line

Height

WidthDepth

Practice

Take a few minutes to copy EACH of these isometric figures on a practice sheet

3.

4.Erase where you need to

Add lines for width parallel to the width axis

Finish the cube with lines for depth parallel to the depth axis

Practice

Draw an isometric sketch of the boxes in the front of the room

This is Isometric Paper

Horizon

To make drawing easierUse isometric paper

Graph paper with linesThat follow isometric60-degree axes

Use this to practice Drawing isometricfigures

More Practice

There are seven 3-D figures made of cubes on your work sheet.

Construct each using plastic cubes.

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More Practice

Then draw each on isometric paper.

A standard method of 3-dimentional (3D) drawing that shows the most detail about three adjacent sides of an object.

Isometric Projection