The document discusses isometric projection, which is a method for visually representing three-dimensional objects in two dimensions in technical drawings. It defines key terms like isometric axes and lines. The steps for constructing an isometric projection are outlined, including defining the axes and adding details to blocks. Various types of objects that can be drawn using isometric projection are described, such as those with normal, oblique, or curved surfaces. Circles are approximated as ellipses, while curved lines use a series of offset points.

1. Isometric Projection

2. Isometric Projection
• 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 angles between
any two of them are 120 degrees.

3. Isometric Terminology
• The three coordinate axes are called isometric
axes
• Any line parallel to isometric axes is called
isometric line
• A non-isometric line is a line not parallel to any
one of the three isometric axis
• In isometric projection of cube, the faces of the
cube and any plane parallel to them is called
isometric planes

4. Isometric Scale
• True lengths of the edges of the object
are equally foreshortened
• Correct isometric projection can be
drawn using an isometric scale (always
smaller than ordinary scale)

5. Isometric Drawing
• Isometric Projection:
Drawing prepared
with isometric scale on
isometric axes
Isometric Drawing:
Drawing prepared
with ordinary scale
on isometric axes

6. Steps for construction of Isometric :
Step 1
Isometric sketches begin with defining
isometric axes, three lines, one vertical
and two drawn at 30° from the
horizontal.

7. Step 2
Three lines of the isometric axes
represent the three primary dimensions
of the object: width, height, and depth

8. Step 3
Draw the rest of the isometric block.

9. Step 4
Add details to the block starting from
the front face. Then add details to the
other faces.

10. Step 5
Darken all visible lines to complete the
isometric sketch. (make sure that
construction lines are light)

11. • Axonometric projection shows all 3 dimensions, length, width and
height.
• The isometric lines are only drawn to scale. Objects composed
entirely of isometric lines can be drawn by taking all
measurements parallel to main edges of the enclosing box.
• Non-isometric lines are drawn by transferring the ordinates
(which are on isometric lines) of the end of the lines
• Inclined and oblique surfaces are drawn using end coordinates.
Box construction and offset measurements are common methods
• In an isometric drawing, an angle never appears in its true size.
Angles, irregular curves require special techniques

12. Objects with Normal Surfaces
Make an Isometric Drawing with corner
A at the bottom

14. Objects with Oblique Surfaces
• Make an Isometric Drawing with corner
A at the bottom

16. Objects with Non-isometric Lines
• Make an Isometric Drawing with apex A
facing front

17. Non-isometric lines are drawn with box construction and
offset measurements
Non-isometric lines are not drawn in true length in
isometric drawing (BA is shorter than CA in this drawing)

18. Irregular Objects
• Make an Isometric Drawing of the
following irregular object (pyramid)

19. • OA and OB offsets help to locate apex O
• Complete box construction may not be needed in each
case

20. Objects with Circular Geometry
•A circle in a orthographic projection will appear as an
ellipse in an isometric drawing.
•Instead of actual ellipses often approximate ellipses are
drawn for isometric drawing.
•Four-centre ellipses are used to approximate ellipses on
isometric planes.
How to draw four-centre ellipse???

21. •Draw the isometric centre lines of the circle. Using the centre
lines, draw an isometric square with sides equal to the diameter of
the circle.
•From the near corners of the box, draw two large arcs with
radius R, using the two red points as centres.
•Draw the two smaller arcs with radius r, using two green points as
centres.

22. Cylinder

23. Objects with Circular Geometry

24. Objects with Non-Circular Curved Surfaces
• Make an Isometric Drawing of the
following curved object

25. •A line that appears as a noncircular curve in a normal orthographic
view of an object appears as a non-isometric line in an isometric
drawing.
•Curves may be drawn using a series of points by measuring along the
normal lines in the orthographic view (offset measurements) and
transferring these points on isometric drawing. Accuracy increases
with number of points.

26. Presented By
Enrollment No. Name
130170111090 RANA ABHIMANYU S.
130170111091 RATHAWA JAYDEVSINH
130170111092 RATHOR VIJENDRASINGH R.
130170111094 RATHWA VIKAS P.
130170111090 RUDRA PAWAN M.

27. Hope you enjoyed our
presentation.
Thank you