Engineering Drawing and Plans PDF

POLYTECHNIC UNIVERSITY OF THE PHILIPPINES Science Department College of Engineering and Architecture Anonas Street, Sta Mesa Manila ENSC 011 Engineering Drawing and Plans ARSENIO LIWAG DOMINGO 1 ...

POLYTECHNIC UNIVERSITY OF THE PHILIPPINES Science Department College of Engineering and Architecture Anonas Street, Sta Mesa Manila ENSC 011 Engineering Drawing and Plans ARSENIO LIWAG DOMINGO 1  Engineering Drawing and Plans (ENSC 011) Author by Engr Arsenio Liwag Domingo Registered Professional Civil Engineer Registered Professional Environmental and Sanitary Engineer Master of Science in Construction Management ALL RIGHTS RESERVED. No part of this learning module may be reproduced, used in any form, or by any means graphic, electronic, or mechanical, including photocopying, recording, or information storage and retrieval system without written permission from the authors and the University. Published and distributed by: Polytechnic University of the Philippines Address: CEA Building, Anonas St. Sta Mesa Manila Website: [email protected] Email: [email protected] Tel. No.:+632-853351/ 5335-1787 / 5335-1777 2  Lesson 3 ( MODULE 3) INSTRUMENMTAL DRAWING INTRODUCTION Instrumental Drawing is sometimes referred to as technical drawings, mechanical drawings or working drawings that requires the use of necessary drawing instruments. LEARNING OBJECTIVES 1. To familiarize the students in all kinds of drafting instruments. 2. To enhance the student how to draw with the aid of instruments. 3. To familiarize the student in the functions of every instruments. 4. To. gain more techniques on how to use the different types of drawing instruments. LECTURE DISCUSSION BASIC INSTRUMENTS AND EQUIPMENT FOR DRAWING Drafting Machines - A devise used extensively by draftsmen. It replaces the T- squares, scale, triangle and protractor. The machine consists of two movable arms or links which make it possible to locate the horizontal and vertical straightedges at any desire position. A controlling or index head allows the scale for straightedges to be set at any angle. Its Drafting Machine is not available. Drawing Board will do. T-Square - used for drawing horizontal lines and for accurate mounting of drawing plates. This is also used as guide to the triangles in drawing vertical and slanting lines. 32 Technical Pen - The most common pen used for inking the drawing instead of Ruling pen. The thickness for the line drawn expressed in millimeter will depend on the size of the technical pen needle. Triangles - Used as guide for drawing vertical and inclined lines particularly at standard angles 30”, 45” and 60” by placing these triangles firmly against the working edge of the T- square. French Curves – An instrument use as guide for drawing irregular curves that cannot be performed by compass. A set of French Curve must at least three pieces. Compass – Use for drawing arcs and circle. It has a fixed pin in one leg and the other has an adjustable screw to hold lead, compass adaptor and pin to perform. 33 Divider – Use for transferring measurements or for dividing lines into any number of equal parts. Compass Adaptor – A devise that can be attach to the adjustable screw of the compass for the purpose of holding technical pen. Triangular Scale - To prepare technical drawings full size or to a variety of reduced or enlarge sizes. Templates – A rules type plastic tool with opening of different shapes and letters cut into it to serve as guide by technical pen needle. 34 Protractor - Use for measuring angles. These are two types of protractor the semi-circular and the circular type. Pencil – It leads were classified as Hard (H) Medium – Soft (HB) and Soft (B). These lead classifications are governed to some extent by the type of drawing made. Draftsmen often prepare to use mechanical Pencil. Eraser - Use for removing error line drawn by using pencil or ink without making much damage to the drawing plates. Erasing Shield - A rectangle thin sheet of metal or plastic with holes various shape shield is used to protect the plate when removing error lines. 35 The scale – It is a measuring instrument and should not be used to draw lines. Scale are availability in flat and triangular styles. The triangular style is the one most used in schools. 36 37