Project Overview  Structural part Introduction  Laser cutting & forming  Model Making  Designing & Developing  Manufacturing  Building & Analysing

LESSON 05

LESSON 5 STARTER Key words: CAD, Library, heat processes, acrylic, MDF, profile, forming. Learning objective: Explore the properties of plastics to produce a range of unique component parts, use a range of tools to form and shape acrylic parts, make high quality and accurate parts for your robot solution. Properties of Plastics What are the useful properties acrylic has that makes it suited to the manufacture of products and prototypes? Task: Complete the table of properties describing each property and how it is useful for making products and prototypes. Characteristic/PropertyDescription Stiff/tough BrittleThe material is brittle meaning that it can crack or shattered with the right amount of force. This can help to cut large sheets if they are scored first. Durable Insulator of electricity Polishes well Hard to scratchThe material has a surface quality that means it is hard to mark the surface with scratches. This can help to prevent accidental damage during making. Plastic memory

Manufacturing Parts Stages of manufacture Today you are going to follow these steps to manufacture your parts… Organise your parts into as small a space as possible to minimise material and reduce laser cutting time Heat along score lines using a strip heater Bend and form parts in stages. When parts have multiple bends, plan which order to bend the parts in so that they fit into your strip heater guard.

Manufacturing Parts Working with Plastics Plastics can be shaped and formed using heat. When heat is applied to the material, it absorbs the heat and moves closer to its melting temperature. Before it can reach its melting point, it will reach a softening point, where the material will take considerably less effort to change its shape. It the material is too cool, the brittle property will still remain, and the material may crack or shatter. It the material is too hot, the material will (as you might expect) begin to burn or melt towards a liquid state. It is therefore important to monitor and control the heating of plastics carefully. Task: Explore the use of the following tools to change and form plastic samples - heat gun - strip heater - plastics oven Strip heater Plastics oven Heat gun

Manufacturing Parts Complete all parts Form all parts on the strip heater. If parts need to be adjusted, use a heat gun to heat and soften areas and form them, or a plastic oven to reheat the entire part and return it back to its original shape (using plastic memory). Task: Consider a range of tools you can use to check the quality and accuracy of parts, and use them to check each before assembly. Use: - set square - ruler - micrometre (if needed) - bevelled edge

LESSON 5 PLENARY As a class, let us consider the following questions? A. Why is being brittle a useful property for a plastic? What product might use acrylic because it is brittle? B. How do you create different forming outcomes from a heat gun, strip heater and plastic oven? C. How can jigs, formers and templates help to improve accuracy when forming plastic parts? D. How does plastic memory help industry to make products?

Summary Today you have:  Learnt about material properties by exploring heating processes and plastics  Used a range of tools and techniques to create accurate parts  Developed a working understanding of how to shape and form plastics for prototyping Learning objective: Explore the properties of plastics to produce a range of unique component parts, use a range of tools to form and shape acrylic parts, make high quality and accurate parts for your robot solution.