Lesson Notes By Weeks and Term v4 - SHS 3

Lesson Video

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Performance objectives

• Describe the basic principles of 3D printing.
• Identify materials suitable for 3D printing.
• Use CAD software to create a simple 3D model.
• Design a prototype using 3D printing.
• Evaluate and suggest improvements for your designs.

Lesson summary

This lesson introduces students to the revolutionary technology of 3D printing, also known as Additive Manufacturing. In Ghana, where innovation and local manufacturing are becoming increasingly important, understanding 3D printing opens doors to entrepreneurship, rapid prototyping, and solving everyday problems. Instead of cutting away material to create an object (like a carpenter carving wood), 3D printing builds an object layer by layer from a digital design. This lesson will equip students with the knowledge to describe this process and the foundational skills to design and prepare a model for printing, transforming a digital idea into a physical object.

Lesson notes

2.1. Additive vs. Subtractive Manufacturing

This is the most important concept to understand first. Subtractive Manufacturing: This is the traditional way of making things. You start with a larger block of material and remove (subtract) parts of it to get your desired shape. Ghanaian Example: A wood carver in Aburi starts with a log of wood and carves away pieces to create a stool or a mask. A machinist starts with a block of metal and drills, cuts, and grinds it to make a machine part. This process can be wasteful as the removed material becomes scrap. Additive Manufacturing (3D Printing): This is the modern approach. You start with nothing and add material, layer by tiny layer, to build up your final object. Analogy: Think of building a house with blocks. You add blocks one by one until the wall is complete. 3D printing does the same, but with materials like plastic, and the layers are incredibly thin. This process is very efficient and produces minimal waste. 2.2. The 3D Printing Workflow: From Idea to Object

The process of 3D printing can be broken down into five main stages.

Stage 1: 3D Modelling (CAD - Computer-Aided Design) This is the starting point. You must first create a digital blueprint of the object you want to print. This is done using CAD software on a computer. What it is: Software that allows you to draw and model objects in three dimensions (length, width, height). Examples of Software: Tinkercad: Free, web-based, and very easy for beginners. Excellent for starting. Fusion 360 / Onshape: More advanced, powerful, and used by professionals. Free for students. Process: You use the software to create shapes (cubes, cylinders), combine them, subtract from them, and modify them until you have your final design. For example, to design a keychain, you might create a flat rectangle and then add raised letters on top of it.

Evaluation guide

• Describe and perform operations using 3D printers.
• Group work/collaborative learning:
• Guide learners to perform design for manufacturability incorporating CAD applications
• used to create the model for 3D printers in mixed ability groups E.g., Creating a simple