Lesson Notes By Weeks and Term v4 - SHS 3
Design and Drawing for Manufacture
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Design and Drawing for Manufacture
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Manufacturing Engineering
Class: SHS 3
Term: 2nd Term
Week: 1
Grade code: 2.2.1.LI.2
Strand code: 2
Sub-strand code: 1
Content standard code: 2.2.1.CS.2
Indicator code: 2.2.1.LI.2
Theme: Design and Prototyping
Subtheme: Design and Drawing for Manufacture
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
This lesson introduces a fundamental language of engineering and manufacturing: First Angle Orthographic Projection. Imagine you are a skilled carpenter in Accra, a welder in Tema, or a fashion designer in Kumasi. How do you communicate your brilliant idea for a new chair, a metal gate, or a complex dress to your team so they can build it exactly as you imagined? A simple sketch is often not enough. Orthographic projection is the standard method used worldwide to create technical drawings that show every detail of an object with no ambiguity. It is the universal language that connects the designer's mind to the hands of the manufacturer.
2.1. Why We Need More Than Just a Picture
A picture or a 3D sketch (like an isometric drawing) is great for showing what a product looks like. However, for the person who has to *make* it, it can be confusing. Hidden Details: You cannot see what's happening on the back or inside the object. True Shapes and Sizes: Angles and lengths can look distorted. A circle on a sloped surface will look like an oval.
To solve this, engineers use Orthographic Projection.
Definition: Orthographic Projection is a way of representing a three-dimensional (3D) object in two dimensions (2D). It involves viewing the object from different directions (front, top, side) at a 90° angle to the object's face and drawing what you see. The word "ortho" means "right" or "90 degrees", and "graphic" means "drawing". 2.2. The "Glass Box" Analogy