Machine Drawing

717 Pages·2008·75.755 MB·English

by  Singh

M A C H I N E
D R A W I N G
Includes AutoCAD
About the Author
The author graduated in Mechanical Engineering from Jodhpur
University in 1963. While completing his Masters in 1970, he
also served at Malviya Regional Engineering College, Jaipur.
He acquired his Ph.D. degree in 1979 from Motilal Nehru
Regional Engineering College, Allahabad. As one of the most
distinguished faculty member of his college, he also served
as Professor and Head of Mechanical Engineering Department
followed by Dean Academic and Dean Research and Consu-
ltancy position.
Many Ph.D. students have benefitted from his guidance in-
cluding private and public companies to whom he has provided
consulting services. He has many research papers to his credit
in national and international journals and is also a life member
of ISTE and fellow member of Institution of Engineers, India.
With over 44 years of teaching experience, he is one of the most knowledgeable academicians in
machine drawing and AutoCAD. With over 15 years of international teaching experience, he has served
as faculty member for various universities abroad.
The author’s previous book, Working with AutoCAD 2000, published by Tata McGraw-Hill, was
widely accepted in India and abroad. He is pleased to introduce this new book that leverages modern day
technology using AutoCAD. Use of computer in every field and drawing too has motivated him to write
the book on Machine Drawing explaining the use of computer chapter by chapter.
M A C H I N E
D R A W I N G
Includes AutoCAD
Ajeet Singh
Retired Professor and
Head of Mechanical Engineering Department,
Motilal Nehru Institute of Technology,
Allahabad
Tata McGraw-Hill Publishing Company Limited
NEW DELHI
McGraw-Hill Offices
New Delhi New York St Louis San Francisco Auckland Bogotá Caracas
Kuala Lumpur Lisbon London Madrid MexicoCity Milan Montreal
SanJuan Santiago Singapore Sydney Tokyo Toronto
Published by Tata McGraw-Hill Publishing Company Limited,
7 West Patel Nagar, New Delhi 110 008.
Copyright © 2008, by Tata McGraw-Hill Publishing Company Limited.
No part of this publication may be reproduced or distributed in any form or by any means, electronic, mechani-
cal, photocopying, recording, or otherwise or stored in a database or retrieval system without the prior written
permission of the publishers. The program listings (if any) may be entered, stored and executed in a computer
system, but they may not be reproduced for publication.
This edition can be exported from India only by the publishers,
Tata McGraw-Hill Publishing Company Limited.
ISBN-13: 978-0-07-065992-6
ISBN-10: 0-07-065992-3
Managing Director: Ajay Shukla
Publishing Gen. Manager—SEM & Tech Ed: Vibha Mahajan
Asst. Sponsoring Editor—SEM & Tech Ed: Shukti Mukherjee
Jr. Editorial Executive: Sandhya Chandrasekhar
Executive—Editorial Services: Sohini Mukherjee
Senior Proof Reader: Suneeta S. Bohra
Deputy General Manager—Higher Education & Sales: Michael J. Cruz
Asst. Product Manager—SEM & Tech Ed: Biju Ganesan
Controller—Production: Rajender P. Ghansela
Asst. General Manager—Production: B.L. Dogra
Information contained in this work has been obtained by Tata McGraw-Hill, from sources believed to
be reliable. However, neither Tata McGraw-Hill nor its authors guarantee the accuracy or
completeness of any information published herein, and neither Tata McGraw-Hill nor its authors shall
be responsible for any errors, omissions, or damages arising out of use of this information. This work
is published with the understanding that Tata McGraw-Hill and its authors are supplying information
but are not attempting to render engineering or other professional services. If such services are
required, the assistance of an appropriate professional should be sought.
Typeset at Script Makers,19, A1-B, DDA Market, Paschim Vihar, New Delhi 110 063 and Printed at Sai Printo
Pack, Pvt. Ltd., A-102/4, Okhla Industrial Area, Phase-II, New Delhi-110 020.
Cover Printer: Rashtriya Printer
RQLYCRDXDRQCY
Dedicated to my grandchildren
Gaganjit, Karanjit, Ananya, Neha and Tanvi
Preface
Any machine part which is produced is first designed and then its drawing is prepared. The industry then
manufactures the part according to the details given in the drawing. Thus, drawing is the only means of
communication between the design office and the manufacturing shop floors. Hence Engineering Draw-
ing is quite an important communication tool for engineers.
Engineering drawings were made manually in the past but now they are made with the help of com-
puters, and are called Computer Aided Drafting (CAD). There are many good books in the market on
engineering drawing but only a few of them cover CAD. Some books give CAD as only a single small
chapter in the end, which does not help a student in correlating the art of drawing with CAD.
There are some good books which focus solely on CAD. They describe the tools available in the
software with a few examples. This book is written as a combination of both manual and computer
methods which run in parallel, chapter by chapter. The idea is that a student who makes a drawing
manually, should be able to create a similar drawing with the help of a computer. It will give a better
understanding of the use of the software for engineering-drawing purposes. The examples selected for
AutoCAD cover a majority of the relevant commands. The software is explained by showing actual
toolbars and dialog boxes which appear on the screen to enhance the understanding of students.
The software adopted in this book is AutoCAD 2005. For more details on the subject of CAD,
readers can consult the other book of the author, Working with AutoCAD 2000. A majority of the
commands used in AutoCAD 2005 are the same as those in AutoCAD 2000, and only a few new
commands have been added.
This book not only gives elaborate drawings, but an effort has been made to describe all the basic
knowledge required for each topic. The information given will be quite useful to answer questions asked
in the viva-voce examinations.
The contents of the book are selected to cover the syllabi of many good universities/institutions
offering machine drawing. Some chapters like Applied Geometry, Surface Developments, Intersections,
Cams, Jigs and Fixtures, etc., are not given in the book as some universities do not have these topics in
their syllabi but these chapters will be put on the internet to make the book comprehensive. The chapters
have been arranged in a logical order for step-by-step mastering of the subject. The problems chosen are
such that a student is able to finish them in a usual class of three hours.
The contents are such that at least 2 semesters are required to finish the whole book at the diploma or
the degree level. The book is suitable for first year degree courses in Civil, Mechanical and Electrical
engineering and the second year of Mechanical engineering courses. The production drawings section
of the book on Tolerances, Limits, Fits, Geometric Tolerances and Surface Finish, etc., is very helpful
viii Preface
for practicing engineers as well. The internet websites given in the Appendix makes the book useful for
any person searching information on a topic concerning machine drawing.
The conventions and terminology used in the book are mostly as per the Bureau of Indian Standards
(BIS). But wherever there are different terms by BIS and AutoCAD, the terms of AutoCAD have been
used so that students do not get confused while using the software.
Explanations are accompanied by many pictorial drawings for better visualization of the concept.
The author has had a long experience of 44 years of teaching this subject and is fully aware of the
common mistakes which students commit. Therefore, these mistakes have been pointed out so that
students do not repeat the same.
The book has the following important features:
∑ Each chapter of the book has a summary at its beginning. This helps students revise the course
quickly at the time of examination.
∑ The book has many solved examples on manual drafting as well as on CAD to give a comprehen-
sive idea to the students.
∑ Theory questions at the end of each chapter help students know as to what type of questions can
be asked on the subject. They also help the teacher to select questions for setting examination
papers.
∑ Multiple choice questions are given at the end of each chapter for evaluating students quickly for
short quizzes, etc.
∑ Fill up the blank questions have been so chosen that they check the key knowledge points of the
chapter.
∑ A large number of unsolved problems for practice are given to create a thorough grasp on the
concepts of the drawing. They also form a good question bank for the teacher to set examination
papers. Solutions of the unsolved problems have not been given intentionally, otherwise students
just copy from the book without understanding.
The contents of the book are divided into six sections:
Section A The first chapter deals with the importance of drawing and Fundamentals of Drawing
while the second chapter is on the general tools available in CAD. The initial settings, and the draw and
modify commands are explained with the help of solved examples. The following chapters are on the
materials and tools used for drawing, standard conventions for lines, lettering, and dimensions.
Section B This is about Projection Methods. Various methods of projections like Orthographic, Iso-
metric, Oblique, Perspective, etc., are explained to fully describe a 3D object on a 2D sheet. This helps
to view an object from any side and to understand the methods of visualization.
Section C This is about Joints and Couplings. Permanent joints like riveted and welded joints are
described. Temporary joints formed by bolts/nuts, cotter, shaft couplings and pipe joints are also
explained. CAD can be of help in copying a part in rectangular or polar array form. Use of this tool for
copying many parts in an array is explained. How the drawings stored in a graphic library can be used in
creating drawings for the joints and couplings are demonstrated here by examples. Sections A, B and C
form the first course on Engineering Drawing for a majority of the universities/colleges and deal with all
the disciplines of engineering.
Preface ix
Section D This concentrates on Production drawings to be used in the shop floor. The mating parts
have to be specified by a type of standard fit required for an application. It is not possible to manufacture
any part of the exact dimensions put on the drawing and hence a certain amount of tolerance is also to be
put in addition to the basic dimensions. The type of machine to be used for manufacturing is decided by
the type of surface finish mentioned on the drawing. Geometric tolerances like squareness, flatness, etc.,
are sometimes specified on production drawings. Standard methods to specify materials and all this
information is described in this section. How AutoCAD helps in putting these values very easily on the
drawing is explained. This section and the next few sections are mainly for mechanical engineers and is
given in the second course on machine drawing. This can be useful for practicing engineers as well.
Section E This deals with Machine Parts like springs, belts and pulleys, bearings, and gears to trans-
mit power. AutoLISP is a programming language to be used in AutoCAD. Fundamentals of this lan-
guage are given to create parametric drawings. Once a program is made, it can be used to create a
drawing by defining the values of the variable sizes.
Section F This is on the Part and Assembly Drawings. Machines are made by assembling different
parts. How the parts are to be joined together are explained here. The main important parts of internal
combustion engines, steam power plants are selected for these drawings. Some parts of the machine
tools and hand tools have also been included. The drawings created as part drawings can be assembled
very easily using AutoCAD to produce an assembly drawing.
Due to development of internet facilities, useful websites for different topics are given in Appendix I.
Appendix II contains Standards.
The Online Learning Center of the book www.mhhe.com/singh/md provides a vast range of supple-
ments. Instructors can take advantage of the Solution Manual and Power Point slides which can be
used as effective teaching aids. For students, there are chapters on Applied Geometry, Developments,
Intersections, Chains, CAMS, Rotary Machines, Jigs and Fixtures as well as Sample Question Paper
with Solutions.
I am sure that the contents of the book will help readers in getting sufficient proficiency and knowl-
edge on machine drawing and CAD for mechanical drawings.
No human being is perfect. Errors and omissions are always possible from any one in spite of the best
efforts. I hope the readers will take them in proper spirit and inform the publisher/author for
improvements and corrections in the subsequent editions.
Constructive suggestions for the improvement of the book are most welcome at my email address:
[email protected].
DR. AJEET SINGH
5 June 2007
Acknowledgements
The manuscript of the book and drawings were finalized at Salalah College of Technology, Salalah,
Sultanate of Oman where I was working during that period. I am thankful to the Ministry of Manpower and
the college administration for providing excellent computing facilities in the department.
I convey my sincere thanks to Dr. R.R. Gaur, Professor of Mechanical Engineering, Indian Institute
of Technology, Delhi, for his valuable suggestions during the initial discussions for the book. I am
thankful to my colleagues for their help and academic discussions from time to time regarding the book.
I would also like to thank the editorial and production teams of Tata McGraw-Hill, who have been
very cooperative and fast in communication even while they were located thousands of kilometres away.
The book has undergone thorough reviews by some eminent academicians and the remarks of each
have been very encouraging, mentioning the usefulness and uniqueness of the book. Their names are
listed below.
Name Affiliation
Prof. Goutam Ghosh Department of Mechanical Engineering
Future Institute of Engineering and Management, Kolkata
Prof. D K Mondal Department of Mechanical Engineering Jadavpur University, Kolkata
Prof. Samar Chandra Mondal Department of Mechanical Engineering Jadavpur University, Kolkata
Prof. R S Deshmukh Department of Mechanical Engineering Vidhya Vardhini College of
Engineering and Technology, Thane
Prof. G N Kotwal Department of Mechanical Engineering
Vishwakarma College of Engineering, Pune
Prof. Sundareswaran Department of Mechanical Engineering, Anna University, Chennai
Mr. Abdul Shareiff Department of Mechanical Engineering,
Sri Siddhartha Institute of Technology, Tumkur
Prof. Raman Bedi Department of Mechanical Engineering
National Institute of Technology, Jalandhar
It will not be out of place to mention, that I would have not been a professional and an author, without
the encouragement of my parents right from my childhood. I thank my wife, Mrs. Kanwaljeet, for reliev-
ing me from the domestic duties to spare time for the book and bear my engagement in the book. Thanks
are due to my daughter Mrs. Maneet Kaur for the proofreading of the book and my daughters
Mrs. Diljeet Kaur and Mrs. Preety Singh who had inspired me to take up this work.
AJEET SINGH
First Look
Integrated course material for manual machine
drawing and Computer Aided Drafting (CAD)
∑ First course in Engineering Drawing
∑ Detailed course on Machine Drawing
MEANT FOR ∑ Practicing Engineers
Section A–Drawing Fundamentals (6 Chapters)
Section B–Projection methods (5 Chapters)
Section C–Joints and couplings (7 Chapters)
Section D–Production drawings (4 Chapters)
Section E–Machine parts (4 Chapters)
CONTENTS
Section F–Part and Assembly drawings (4 Chapters)
Arranged in a logical order
QUICK STUDY
Every chapter gives a comprehensive
introduction in the beginning.
AutoCAD Fundamentals of
AutoCAD are described
concisely in a separate chapter
on AutoCAD.
RELEVANT THEORY
For viva voce examination—
Key points are shown in bold.