Isomeric projection has a proper role in Engineering drawing without this the engineering drawing is incomplete. This Assignment slides are created by Alamdar Naqvi. Student of BS Electrical Engineering of GC University Faisabad.

1. Engineering Drawing Lab Manual

2. Engineering Drawing Lab Manual
Experiment No. 05
Sketch the Isometric projection
OBJECTIVE:
Draw a pictorial or an isometric projection from orthographic projections of simple solids or
objects bounded by plane surfaces.
EQUIPMENT:
 Set squares
 Drawing board
 Protector
 Mini drafter
 T square
 Drawing sheet
 Pencils
 Templates
 Compass
Theory:
Isometric projection is a method for visually representing three-dimensional objects in two
dimensions in technical and engineering drawings. It is an axonometric projection in which the
three coordinate axes appear equally foreshortened and the angle between any two of them is 120
degrees. In isometric projection the object, instead of having its faces parallel to the plane, is
rotated and tilted in such a way that all the principal faces on the object are inclined. The
projected views are then drawn connected so that they form an object.
An isometric drawing is a type of 3D drawing that is set out using 30-degree angles. It's a type of
axonometric drawing in which the same scale is used for every axis, resulting in a non-distorted
image. Isometric grids are relatively easy to set up, and once you've mastered the basics of
isometric drawing, creating a freehand isometric sketch is quite straightforward.
Note: All dimensions are in mm

3. Engineering Drawing Lab Manual
PROCEDURE:
1. Select axes along which to block in height, width, and depth dimensions
2. Locate main areas to be removed from the overall block. Lightly sketch along isometric
axes to define portion to be removed.
3. Lightly block in any remaining portions to be removed through the whole block.
4. Lightly block in features to be removed from the remaining shape along isometric axes
5. All measurements drawn backward is one side the original measurement.
6. Between any two extension lines, there must be one and only one dimension line bearing
one dimension.
7. As far as possible, all the dimensions should be placed outside the views. Inside
dimensions are preferred only if they are clearer and more easily readable.
8. The same unit of length should be used for all the dimensions on a drawing.
9. The unit should not be written after each dimension, but a note mentioning the unit
should be placed below the drawing.
10. Dimension lines should not cross each other. Dimension lines should also not cross any
other lines of the object.
Draw the Isothermal projection of following figure

4. Engineering Drawing Lab Manual