Engineering Graphics

Dear Students, Good Morning and a warm welcome to today's class. It feels really nice to meet up for yet another class this morning. From your interactions and responses on the previous blogs / EG WhatsApp Group, I am pleased to say that you all are doing good work. However, I expect an even better response in all the future classes.  Recall that in the last 6 sessions, you have leant the basics of Isometric Projection that included: 1. Essentials of Isometric Projection, 2. Planar figures, 3. Frustums, 4. Single Solids and 5. Combination of Solids. 'Combination of Solids'  is the last topic in Unit 1 and we will spend a few more classes in grasping this topic in a manner that is nothing less than perfection. We expect a total of 25 to 28 marks being alloted to this unit in the Final CBSE Examination 2021.   I encourage you to ask your doubts and queries by writing in the comments section at the end of the blog and I promise to make sincere efforts a

Isometric Projection - 6 Good Morning students and a warm welcome to each of you to today's class. Let me start by congratulating you for taking online classes and making good progress in grasping intricate concepts over the last 5 sessions. Your response (i.e. submission of exercise question answers) is quite encouraging and hope you will continue to do so in times to come.    Recall that in the last 5 sessions, you have leant the basics of Isometric Projection that included essentials of isometric projection, planar figures, frustums and single solids. I hope that you would have grasped the concepts well and feel confident in learning the next topic that is also the last in this unit. I encourage you to ask your doubts and queries by writing in the comments section at the end of the blog and I will make sincere effort at resolving them while you are working on your exercise. I will also expect quick response with answers from you.      Today we will learn about  Isom

Isometric Projection - 5 Good Morning students and a warm welcome to each of you to today's class. In the last four classes, you have leant the basics of Isometric Projection that included essentials of isometric projection, planar figures and frustums. Today we will learn about Isometric Projection of single solids.       Fig: 1 : Isometric Projection of a Hexagonal Prism. Single solids could be cylinders, prisms or pyramids with triangle, square, pentagon and hexagon as face and/or base. The concepts leant in the previous classes will be used here as well.  Recap Time: Concepts learnt previously 1. Draw the helping figure (if required) and label it appropriately. (PQRS) 2. Draw reduced or enlarged planar figures (in case of frustum). 3. Always use the Box method. 4. Draw 30-30 AXIS, 5. Draw 30-30 CROSS, 6. Finalise the Projection by darkening the visible edges of the object. 7. Indicate direction of viewing, mention all the given dimensions with p

Isometric Projection - 4 Dear Students, Good Morning! Today we will study Isometric Projection of Frustums placed in inverted position. We will start with understanding what an inverted Frustum is.   1. What is an inverted Frustum?  A frustum in which the base edge is smaller than the top edge is called as an inverted frustum. Refer figure above. There is no difference in construction of its Isometric Projection when compared to a regular/normal frustum. We adopt the same procedure as studied yesterday in blog titled, Isometric Projection - 3. 2. In what way can a Frustum be positioned? In almost all the questions asked in examination, the solid axis of the frustum will be perpendicular to the HP. The only parameter to take care is the placing of the base on the frustum on the HP. For example, two edges of the base of a frustum of a hexagonal pyramid could either be paraller or perpendicular to the VP. In case of a frustum of a pentogonal pyramid, one base edge

Isometric Projection - 3 Dear Students, We have learnt some basic concepts of Isometric Projection in the last two classes and solved some problems pertaining to planar figures. Now we shall learn to make isometric projection of  frustums . A few examples of frustums                             Figure 1: Frustum of a Square Pyramid                 Figure 2: Frustum of a Hexagonal Pyramid 1. What is a frustum?    A frustum is a truncated part of a cone or a pyramid. In other words the portion of a cone or a pyramid which remains after the upper part has been cut off by a sectioning plane parallel to its base. Refer figures 1 and 2 above. 2. How to draw the isometric projection of a frustum? We follow few basic steps as enlisted below: a). Draw a helping figure: You will draw both the face and the base of a frustum of a pyramid i.e. a small and a big triangle, square, pentagon or a hexagon. Enclose the figure within a box. Mention the title 'HELPI

Isometric Projection - 2 Some basic Concepts.....contd. 1. What is a helping figure and why is it needed? a). You have learnt yesterday that when an Isometric Projection of an object is drawn, its dimensions suffers a reduction of approx. 18.5%. An object may have both, isometric as well as non-isometric edges (lines). Therefore, to help us in drawing the isometric projection on non-isometric edges, we need the help of a 'helping figure'. b). A square and a rectangle do not have non-isometric edges, therefore these shapes (figures) do not need a 'helping figure' to draw their Isometric Projections. However, triangle, pentagon and a hexagon have non-isometric edges, hence we need a helping figure to draw their Isometric Projections. 2. What is another good use of a helping figure? We use a helping figure to mark the centre of the base (or face) through which the solid axis passes. 3. What are the essentials of an Isometric Projection? a). Dire

Isometric Projection - 1                                                         Dear Students,  Let us begin with revising some basic concepts that we have learnt earlier. These will assist you to grasp higher concepts with relative ease. Go through the following points and carefully read the answers that follow. In case you have a clarification to seek, feel free to write in the comments section at the bottom of the blog. At the end there are 3 questions that you have to solve in your drawing file. So here we go... Some Basic Concepts 1. What is Isometric projection/view? a). Isometric projection/view  is a method for visually representing three-dimensional objects in two dimensions (of a paper) in technical  and engineering drawings.  b). It is also called as pictorial drawing . This is how all the objects are viewed by the eye.   c). You would appreciate that 'orthographic projection' (having Top View, Front View and Side View) is slight