Chapter 1: Basic Elements of Drawing

1.1 Introduction

Drawings can be created quickly and precisely using drawing tools. The quality of the tools has a significant impact on how accurate the drawings are. It is simple to achieve desired accuracy using high-quality devices. Therefore, it is crucial to get instruments that are as high-quality as possible.

Below is the list of minimum drawing instruments and other drawing materials which every student must possess:

1. Drawing board

2. T-square

3. Set-squares - 45° and 30°- 60°

4. Scales

5. Protractor

6. French curves

7. Drawing papers

8. Drawing pencils

9. Eraser (Rubber)

10. Drawing pins, clips or adhesive tapes

11. Drafting machine

12. Roll-n-draw

We shall now describe each of the above in details with their uses:      

1).Drawing boards

Drawing boards are scale plastic boards designed specifically for technical drawing. They are used to draw parallel lines easily and precisely, e.g., for three-dimensional projections and much more. They feature a mechanical device with rail-mounted rulers that run horizontally and vertically at an exact 90° angle.

Figure 1.1

Drawing board is made in various sizes. Its selection depends upon the size of the drawing paper to be used. The sizes of drawing boards recommended by the Bureau of Indian Standards (IS:1444-1989) are tabulated in table 1-1. For use in schools and colleges, the last two sizes of the drawing boards are more convenient. Large-size boards are used in drawing offices of engineers and engineering firms.

The drawing board is placed on the table in front of the student, with its working edge on his left side. It is more convenient if the table-top is sloping downwards towards the student. If such a table is not available, the necessary slope can be obtained by placing a suitable block of wood under the distant longer edge of the board.

2). T-square

T-Square is basically a scale attached to a vertical head and as per definition,it is a tool used to draw horizontal lines on the Drawing Sheet, apart from this it is also used to support Set Square which can be used to produce lines in multiple of 15°.

The measuring portion is called Blade and is used to draw horizontal lines on Drawing Sheet. The edge of the scale is called Working Edge.The remaining black portion is called Head/Stock which is used to support the T-Square against the slotted edge of the Drawing Board so that it can facilitate drawing parallel horizonal lines as shown in figure 1.2

Figure 1.2

T-SQUARE is basically available in four different size for different size of sheet namely T0, T1, T2, T3.

3). Set-squares

A triangle-shaped tool that is often made of plastic or metal and is used to draw angles and straight lines. Set squares can also be used to draw perpendicular lines, angles, and complete shapes, such as squares, rectangles, and triangles.

They're particularly helpful for checking to see if a shape has a right angle - a set square will always contain a 90-degree angle, so you can use them to identify these angles in shapes.

Two different types of set squares are present in a geometry box, one with 90-45-45 degree angles and the other with 30-60-90 degree angles.

Figure 1.4

The set-squares are made of wood, tin, celluloid or plastic. Those made of transparent celluloid or plastic are commonly used as they retain their shape and accuracy for a longer time. Two forms of set-squares are in general use. A set-square is triangular in shape with one of the angle as right angle. The 30°-60° set-square of 250 mm length and 45° set-square of 200 mm length are convenient sizes for use in schools and colleges.

Figure1.5

4). Scales

The scales are the ratio of the linear dimension of an element of an object as represented in the original drawing to the actual linear dimension of the same element of the object it