PLACING OF DIMENSIONS

          It is necessary to indicate the size, and other details of the object for the construction and function, using lines, numerals, symbols, notes etc, we indicate the details in a drawing by proper dimensioning. Dimensions are written either above the dimension lines or inserted at the middle by breaking the dimension lines.

Normally dimensions are placed according to either of the following two systems:

1) Aligned System and

2) Unidirectional system

1) Aligned system:

          In Aligned system, the dimension is placed perpendicular to the dimension line in such a way that it may be read from the bottom edge or the right-hand edge of the drawing sheet. The dimension should be placed near the middle and above, clear of the dimension lines.

2) Unidirectional system:

          In unidirectional system, all the dimensions are placed in one direction such that they can be read from the bottom of the drawing. In this system, the dimension lines are broken near the middle for inserting the dimensions. This system is mainly used on large drawings -- as of automobiles etc., where it is inconvenient to read dimensions from the right-hand side.

   

DRAWING SHEET

          Drawing sheet is the medium on which drawings are prepared by means of pencils (or) pen. Drawing Sheets are available in many types and sizes (like A4, A3, A2, A1, A0 etc.,). In general we prepare pencil-drawings, for this the paper we selected should be tough, strong and smooth surface. It's thickness should be uniform and as white as possible. When the rubber eraser is used on it, fibres should not disintegrate. Good quality of paper should be selected for drawings which are to be inked and preserved for a long time. It should be such that the ink does not spread. Thin and cheap quality paper may be used for drawings from which tracings are to be prepared.

          The Standard sizes of drawing papers: ~ recommended by the Bureau Of Indian Standards (B.I.S) are given below

While in the drawing sheet .. first we have to draw border lines and title box and then we have to start drawing

Title block:

          The document's title in an engineering drawing block is found in the bottom right-hand corner of the page. Also known as the information blocks. It includes the part name, the names of the people who worked on the part (design, checking, and approval), the name of the company, the drawing number, ad other relevant information.

          In addition, it includes technical details such as the measurement units, the angle of projection, the surface polish criteria, the scale, and the material of construction. Title blocks are used for a better understanding of all parts of technical drawing.