To create interest and to motivate him in this direction, complete revision of the chapter on assembly drawings is done. The chapter provides individual component drawings and knowing the working mechanism of a subassembly, finally the parts are assembled. Hence, exercises/examples are included starting from simple subassembly to moderately complex assemblies. The chapter on part drawings provides examples Of assembled drawings and the student is expected to make the part drawings after imagining the shapes of them. A revision Of this chapter is supposed to provide the required guidance to the knowledge seeker.
The chapter on computer-aided draught is fully revised keeping in view the present day requirements Of the engineering students. The student should be trained not only to use draught equipment but also to use a computer to produce his latest invention. It is presumed that this chapter will provide him the required soft skills. The centers of excellence should revise the curriculum frequently, based on the changes needed by the academic requirements. Keeping this in view, the contents of the text are updated wherever necessary and incorporated.
It is hoped that the subject content satisfies both students, teachers and paper eaters. AUTHORS PREFACE TO FIRST EDITION Drawing, as an art, is the postulation of the imagination of the scene in its totality by an individual-?the Artist. It has no standard guidelines and boundaries. Engineering drawing on the other hand is the scientific representation of an object, according to certain national and international standards Of practice. It can be understood by all, With the knowledge Of basic principles of drawing.
Machine drawing is the indispensable communicating medium employed in industries, to furnish all the information required for the manufacture and assembly Of the components Of a machine. Industries are required to follow certain draught standards as approved by International Organization for Standards (ISO). When these are followed, drawings prepared by any one can convey the same information to all concerned, irrespective of the firm or even the country. Mechanical engineering students are required to practice the draught standards in full, so that the students after their training can adjust very well in industries.
This book on Machine Drawing is written, following the principles of drawing, as recommended by Bureau to Indian Standards (IBIS), in their standards titled “Engineering raring practice for schools and colleges”; SP:46-1988, This is the only book on Machine Drawing, incorporating the latest standards published till now and made available to the students. Typical changes brought in the standards, in respect of names of orthographic views are listed below. These eliminate the ambiguity if any that existed earlier. The latest designations as recommended below are used throughout this book.
Designation of the views as per 15:696-1972 Designations of the views as per SP:46-1988 I. Front view The view from the front 2. Top view The view from above 3. Left side view The view from the left 4. Right side view The view from the right 5. Bottom view The view from below 6. Rear view The view from the rear The contents Of the book are chosen such that, the student can learn well about the drawing practice of most of the important mechanical engineering components and subassembly, he studies through various courses.
Machine Drawing The principles forking, place of application and method of assembly of all the machine elements dealt with in the book will make the student thorough with the subject of mechanical engineering in general. This will also make the student understand what he is drawing instead of making the drawings mechanically. This book is intended as a text book for all mechanical engineering students, both at degree and diploma level and also students of MAIM. The contents of the book are planned, after thoroughly referring the syllabi requirements of various Indian universities and MAIM courses.
The chapter on Gigs and Fixtures is intended to familiarize the students, with certain production facilities required for accurate machining/fabrication in mass production. The chapters on Limits, Tolerances and Fits and Surface Roughness are intended to correlate drawing to production. In this, sufficient stress is given to geometrical tolerances which is not found in any of the textbooks on the topic. The student, to understand production drawings, must be thorough in these topics. The chapter on Blue Print Reading has been included to train the student to read and understand complicated drawings, including production drawings.
This will be of immense use to him, later in his career. Chapters on Assembly Drawings and Part Drawings are planned with a large number of exercises drawn from wide range of topics of mechanical engineering. The assemblies are selected such that they can be practiced in the available mime in the class. The projects like lathe gear box and automobile gear box are developed and included in the chapter on part drawings, These are mentioned in most tooth latest syllabi but not found in any tooth available books on the subject.
