# Isometric Drawing

Subject : Basic Technology

Class : Basic 9 / JSS 3

Term : 1st Term / First Term

Week: 7

Topic: Isometric Drawing

Previous Knowledge : The pupils have been taught

Production of Materials – Plastics and Rubber

during their previous lesson or class

Behavioural Objectives : By the end of the lesson, learners will be able to

• Say the meaning of Isometric Drawing
• Define Isometric Axes
• Construct Isometric Drawing of Simple Shaped Blocks

Contents:

1. Meaning of Isometric Drawing

2. Isometric Axes

3. Isometric Drawing of Simple Shaped Blocks

4. Drawing Isometric Blocks with Freehand

Meaning of Isometric Drawing

Isometric drawing is a pictorial method of drawing which shows the three faces of an object together. It is a clear way of presenting information about the physical outlook of an object. An isometric drawing is constructed by using a pair of set-squares. The receding lines (Isometric lines) are drawn at 30o to the horizontal plane or x – y line while the other lines are vertical.

Isometric drawings help students to develop their imagination.

Isometric Axes

An isometric drawing is built around three lines called isometric axes, this comprises a vertical axis and two receding axes. Note that the two axes of 30o and there is 120o between the three axes, they are called the isometric axes and on them the drawing is built up.

Isometric axis

Isometric Drawing of Simple Shaped Blocks

Step 1: Draw with set-squares; place the set-square and make sure that both the face and side are inclined at 30o to the horizontal plane.

Step 2: Draw the isometric box that contain the object first. The box must have the overall size of the length, the breadth and the width of the desired object. (Note that this must be drawn with very thin lines)

Step 3: Draw the desired shape with faint lines inside the box using the correct dimension.

Step 4: Draw the correct shape of the object with thick continuous line (i.e. outline.)

Step 5: You may rub off the construction lines or you may not if they are very neat and faint.

Drawing Isometric Blocks with Freehand

Freehand sketching is a method of drawing object without the use of drawing materials except a pencil. Students should try as much as possible to attempt drawing isometric blocks with freehand. It may seem difficult in the beginning but with constant practice, good results will be achieved.

In technical drawing, a freehand sketch is made in exactly the same way as drawing done with instruments. AOX is drawn first, then, the measurement is transferred; constant practice will also help you to achieve good proportion.

Presentation :

The Topic is presented step by step for easy assimilation by the learners.

Step 1 : The teacher revises the previous topics that had been taught during the precious lessons

Step 2 : The subject teacher introduces the new topic of the learners

Step 3 : He or she allows the students to give their own contributions and he corrects them when the needs arise

Assessment / Evaluation

Briefly define the following terms :

• isometric drawing
• isometric axes.