Meaning of Scale Drawing

    Scale drawing is different from ordinary drawing or sketching because it provides an accurate representation of the object (s) under consideration. There are scales for reduction and for enlargement of the size of the object. This is to introduce you to ways of drawing different objects to various scales.

Scale drawing

Let us take a simple object like a cupboard , for an example. Assuming the height of the cupboard is 1800 millimetres, a line of 18 millimeters long can be drawn to represent 1800 millimeters. In scale drawing, this means that each millimeters on the drawing represents 100 millimeters on the object.

    The word ' scale drawing' is a simple statement of basic facts relating to 'size' either by reduced ratio or enlarged ratio. It is not possible to draw the full size of a train on a standard sheet of drawing paper, nor do you a piece of paper as large as the area of the world to be able to produce the world map. Both can be drawn to scale. Once we know the actual size if any object and the ratio in which it is drawn, we can interpret every detail in the drawing accurately.

However , the scale is usually given as a ratio. In scale drawing, the scales are stated in the ' title block and a scale rule is used to take the actual dimension if not stated as well as ratio.

   Having  understood what ' scale drawing'  is , we can now think of a scale for 'decreasing' the size of an object. By this, it is meant that the full size is reduced in ratio, and if the ratio is divided by that proportion, the full size is obtained, e.g .., a scale of 5 millimeters to 40 metres. On the scale, every 5 millimeters represent 40 metres for the actual size. If a line 100 metres long is desired, from the above scale the graduation will then be a 100 metres, 10.0mm on the scale, means 100 metres in actual size.