TECHNO INDIA SALT LAKE

Mechanical Dept.
Report on:-
Development Of Surface In Engineering Drawing

NAME:- Navnit Kumar Singh

SEC:- A
YEAR:- 03RD SEM:- 05th
UNIVERSITY ROLL NO:- 13000715055
UNIVERSITY REG. NO:- 151300110425
PAPER CODE:- ME(581)
 CERTIFICATE

This is to certify that the project report entitled

Development Of Surface In Engineering Drawing

Submitted by Navnit Kumar Singh in partial ful-

Fillment for technical support to core subject.

Engineering is bona fied work carried out under my

guidance and supervision at Techno India, Salt Lake,

Kolkata.

_________
SIGNATURE
 LETTER OF TRANSMITTAL
August 182017
BC Sir
HOD
Department Of Mechanical Engineering
Techno India , Salt Lake

Subject:- Letter Of Transmittal

Dear Sir,
With due respect I,the undersigned student of ME(A) batch has
reported on Development Of Surface In Engineering
Drawing under the course of core subject.
Though we are in learning curve, this report has enabled us to
gain insight into the core fact of technical knowledge. So it beco
-mes as an extremely challenging and intereting experience. Thank
you for your supportive consideration for formulating an idea.
without your inspiration this report would have been an incomplete
one.

Lastly I would be thankful once again if you please give your judicious
advice on effort.

Yours sincerely,
Navnit Kumar Singh
 ACKNOWLEDGEMENT

Firstly,I would like to express my sincere gratitude to my advisor

HOD BC SIR for the continuous support of my study and related
research, for his patience, motivation, and immense knowledge.
His guidance helped me in all the time of research and writing of
this thesis. I could not have imagined having a better advisor and
mentor for my core studies.
Besides my advisor, I would like to thank the rest of my thesis
committee:Prof.S PAL, Prof. ADITI MAJUMDAR, Prof. ARB SIR
and Prof. S MALLICK, for their insightfull comments and
encouragement, but also for thr hard question which incented
me to widen my research from various perspectives.
My sincere thanks also goes to writes who has written the great
books providing more ideas and opportunity to join their team as
intern, and who gave access to the better report.Without its
precious support it would not be possible to conduct this
research.
Also I thank my friends.
Last but not the least,I would like to thank my family: my parents
and to my brothers and sister for supporting me spiritually
throughout writing this report and my life in general.
 CONTENTS

Page No.

Inroduction.

 INTRODUCTION

What is Engineering Drawing??

From the very early days,man realised that if he had to construct any
structure or machine correctly and methodically, he must first record
his ideas become more vivid and forceful if they are shown on paper in
form of a drawing of the structure or machine .Such a drawing will be
of very great help to the man who looks after the contruction of this
structure or machine.

Indeed , Engineering drawing is the language of Engineering. Without

the good knowledge of drawing, an engineer is nowhere and he could
not have constructed the various magnificent structures or intricate
machines.Evidently, any one connected in any way ,with engineering
drawing construction must understand this language of engineers.
Engineering drawing is , therefore, indespensible today and shall
continue to be so as long as engineering and technology continue to
be use in the activities of man.

By means of drawing,the shape,size, finish, colour, and construction of

any object (no matter how complex) can be described accurately and
clearly.
 Development of Surface

A Development is the unfold /unrolled flat /plane figure of a 3-D

object. Imagine that a solid is enclosed in a wrapper of thin material,
such as paper. If this covering is opened out and laid on a flat plane,
the flattened-out paper is the development of the solid. Thus, when
surfaces of a solid are laid out on a plane, the figure obtained is
called its Development.

Here, this figure shows a square prism covered with paper in process
of being opened out. Its development consists of four equal rectangles
and two similar squares for its ends. Each figure shows the true size
and shape of the corresponding surface of the prism. The development
of a solid, thus represents the actual shape of all its surfaces which,
when bent or folded at the edges, would form the solid.
 METHODS OF DEVELOPMENT

Methods of Development of surfaces are:

Parallel line development

Radial line development
Triangulation development
Approximate development

Parallel line development

Parallel line development uses parallel lines to construct the expanded

pattern of each three-dimensional shape. The method divides the
surface into a series of parallel lines to determine the shape of
pattern.Example: Prism, Cylinder.

The cylinder is positioned such that one element lies on the

development plane. The base and top of the cylinder are circles, with a
circumference equal to the length of development. All elements of the
cylinder are parallel and are perpendicular to the base and the top.
When cylinders are developed, all elements are parallel and any
perpendicular section appears as a stretch-out line that is perpendicular
to the elements.
Development of objects with parallel elements or parallel lateral edges
begins by constructing a stretch-out line that is parallel to a right section
of the object and is therefore, perpendicular to the elements or lateral
edges.

In the front view, all lateral edges of the prism appear parallel to each
other and are true length. The lateral edges are also true length in the
development. The length, or the stretch-out , of the development is
equal to the true distance around a right section of the object.
STEP 1. To start the development, draw the stretch-out line in the front
view, along the base of theprism and equal in length to the perimeter of
the prism.
Draw another line in the front view along the top of the prism and equal
in length to the the stretch-out line.
Draw vertical lines between the ends of the two lines, to create the
rectangular pattern of the prism.
STEP 2. Locate the fold line on the pattern by transferring distances
along the stretch-out line in length to the sides of the prism, 1-2,2-3,3-
4,4-1.
Draw thin, dashed vertical lines from points 2,3, and 4 to represent the
fold lines.
Add the bottom and top surfaces of the prism to the development, taking
measurements from the top view. Add the seam to one end of the
development and the bottom and top.

Radial line development

Radial line development uses lines radiating from a centre point to

construct the expanded pattern of each three-dimensional shape.
Example: Cone, Pyramid.

Radial line developments are made from figures such as cones and
pyramids. In the development , all the elements of the figure become
radial lines that have the vertex as their origin. The cone is positioned
such that one element lies on the development plane. The cone is then
unrolled until it is flat on the development plane.
One end of all the elements is at the vertex of the cone. The other ends
describe a curved line.

Development Of right Circular Cone

To begin this development, use a true-length element of the cone as

the radius for an arc and as one side of the development.
A true- length element of a right circular cone is the limiting element of
the cone in the front view. Draw an arc whose length is equal to the
circumference of the base of the cone.
Draw another line from the end of the arc to the apex and draw the
circular base to complete the development.
 Triangulation development

Triangulation developments are made from polyhedrons, single curved

surfaces, and wrapped surfaces. Example: Tetrahedron and other
polyhedrons.

Made from polyhedrons, single-curved surfaces, and wrapped

surfaces.
The development involve subdividing any ruled surface into a series of
triangular areas.
If each side of every triangle is true length, any number of triangles can
be connected into a flat plane to form a development.
Triangulation for singe curved surfaces increases in accuracy through
the use of smaller and more numerous triangles.
Triangulation developments of wrapped surfaces produces only
approximate of those surfaces.
 Approximate development

In approximate development, the shape obtained is only approximate.

After joining, the part is stretched or distorted to obtain the final
shape.Example: Sphere.

An approximate development is one in which stretching or distortion

occurs in the process of creating the development.
The resulting flat surfaces are not the same size and shape as the
corresponding surfaces on the 3-D object.
Wrapped surfaces do not produce true developments, because pairs
of consecutive straight line elements do not form a plane.
Also double curved surfaces, such as a sphere do not produce true a
sphere do not produce true developments, because they do not contin
any straight lines.
 TRUE DEVELOPMENT

A true development is one in which no stretching or distortion of the

surfaces occurs and every surface of the development is the same
size and shape as the corresponding surface on the 3-D object.
Eg: Polyhedrons and single curved surfaces.

Polyhedrons are co posed entirely of plane surfaces that can be

flattened true size onto a plane in a connected sequence.

Single curved surfaces are composed of consecutive pairs of

straight-line elements in the samp plane.