Module 1 : Introduction and geometric constructions

Lecture 1 : Introduction to Engineering Drawing

 

Introduction
Drawing is the Graphical means of expression of technical details without the barrier of a language. Engineering Drawing is the Universal Language for Engineers

Communication in engineering is necessary for effectively transferring one’s ideas to others.  While communicating,  we use our memory to remember objects, sense organs to perceive objects and mind to imagine objects. Our perception are coloured or modified by our past experiences.

We see things around us, perceive the objects and identify them by their names. Later, when we hear these names we can remember these items easily and imagine various features like the shape, size, color, functions  etc,. e.g. if I say that a particular object is having the shape of a cricket bat, it is easy for a high school student to imagine the shape of the object since he has seen a cricket bat and has perceived the object. If I say that a particular object looks like the Dendrite formed during solidification of a metal, then it is difficult for the same student to imagine, since he has not seen a dendrite. His question will “how do a dendrite look like?” when we say that dendrite means tree-like structure,  his imagination can go to different types of trees, but still he may not have a clear picture of the dendrite. If we show him a picture of a dendrite, he can very easily perceive that object.

One picture/drawing is equivalent to several sentences. It is not easy for anyone to make another person understand somebody’s face just by explaining the features. Even if several sentences are used to explain the features of the face, words it would be difficult for the listener to perceive  the image of the face.  However, if you show a sketch or a photograph of the person, all these sentences can be saved. i.e., We grasp information easily if it is illustrated with diagrams, sketches, pictures, etc.

Engineering drawing
Drawings help us in developing our thoughts and ideas in to a final product.  
Drawings are also necessary for engineering industries since they are required and are being used at various stages of development of an engineering product.  Engineering drawing is completely different from artistic drawing, which are used to express aesthetic, philosophical, and abstract ideas. In an industry, these drawings help both the technical as well as commercial staffs at various stages like: