Class Set Simple Machines

Topic Introduction

The Class Set Simple Machines provides a low-threshold approach to important mechanical basics and their physical effect for teaching general science at primary level. Everyday technical functions are constructed and explored in a playful and practical way and encourage reflection. Working alone or in teams, pupils build simple and more sophisticated machines, automatic machines, tools and physical models. Process-related skills are promoted by the solving of problems, in-depth research and suggestions for creative changes to the models.
Fun with tinkering and the enjoyment of perfectly functioning mechanics are just as important elements as the playful development of relevant technical terms using a variety of tasks and their solution examples. By dealing with simple machines, general science lessons help pupils to perceive their environment differently and to recognise the working principles of simple machines like a pattern in multiple everyday applications.

What are simple machines?

The term “simple machines” (also referred to as force-saving, force-converting or labour-saving machines) covers tools or mechanical devices that serve to convert a force or optimise the effect of a force. Examples of simple machines are the rope, the lever, the pulley and the inclined plane (wedge), which are found in some combination in almost every power machine. [1]

This results in a wide variety of topics that can be easily explored by the pupils in a playful way. The task sheets are formulated according to the educational plans in a skills-oriented way. The objective is to control, reflect and evaluate your own thinking when solving problems and thus build up new knowledge. Problems are to be recognised, problem-solving strategies developed and applied.

• Joints and hinges: How can something be pivoted and hinged?
  
• Pawls in many forms and applications: How can something be prevented from moving in the wrong direction?
  
• Lever mechanisms: Experiencing the action of levers, pivoting levers, multiple coupled levers.
  
• Eccentric: Converting a rotary motion into a back-and-forth motion, shown in different scenarios.
  
• Spring mechanisms: Resetting mechanisms by means of spring force, springs as energy stores – shown using natural and easy to grasp model situations.
  
• Wire rope hoists and pulleys – to be tried out step by step in various configurations.
  
• Linear motions along guide rails.

If we look around a little, we see simple and complex mechanisms almost everywhere. They play a large, if often unrecognised or hidden, role in the environment. From simple levers to the mechanisms in a room door to cranes to diverse sophisticated solutions to one and the same task. 
The examination of simple machines is justified because of their high relevance to the world of life and the culturally anchored knowledge that is linked to them. [2]

History

Mechanical structures have existed since the beginning of time, from simple levers to the invention of the wheel and increasingly complex machines. Pulleys, levers and corrugated wheels were already combined with ropes in ancient times to create lifting tools and crane-like constructions. These were mainly used in building work. The principle of the pulley was already known in Greece around 700 BC, and the lever since time immemorial. Archimedes (287-212 BC) formulated the so-called lever principles. In antiquity, the first empirical experiences were also systematised with the help of geometry, mathematics and a wealth of inventive talent, understood better and better and used in applications that can hardly be counted to this day.
Heron of Alexandria, a Greek mathematician and engineer of the first century AD, recorded the wheel, pulley, lever, wedge and screw as elements of simple machines in his writings. Forgotten in the Middle Ages, his text was rediscovered in an Arabic translation during the Renaissance. The engineers of that era added the inclined plane to simple machines. What these have in common is that they are the basic building blocks of any more complex machine mechanics – we would tend to call them machine elements today. They seem almost a little trivial to us in the information age. And yet they are the foundation on which technical civilisation was built. [3]

Further information

[1] https://en.wikipedia.org/wiki/Simple_machine
[2] Simple machines, physics lessons | Issue no. 169/2019, Friedrich Verlag
[3] Niels Boeing, Simple machines as a foundation of modern times, Werkspuren 2|2013