Learn about Mechanics

This course provides an understanding of machines. As such it forms a foundation for understanding the scope and nature of machines; possibilities for achieving more efficient work outcomes with machines; how to make better choices of what machine to use for what job, and how to manage and maintain machinery you use.

Machines include obvious things such as cars and garden equipment; but also machinery used in factories, offices and other workplaces, and machines used to make life easier in our houses, from kitchen appliances to vacuum cleaners. A kitchen food processor is a machine, and are cars and robots. This course is relevant to all of these things.

When you better understand machines, you have a greater capacity to work in any industry. 

Course Content

Lesson 1. Introduction to Engines and Motors

• Introduction
• Power Sources
• Engines
• Steam Engine
• Petrol
• Engine Operating Cycle
• Engine parts
• Four stroke Ignition Engine Cycle
• Two Stroke Ignition Engine Cycle
• Electric motors
• Parts of an electric motor
• AC and DC motors
• Induction and Synchronous motors
• Applied tasks - Changing a wheel, Mending a puncture

Lesson 2. Engine Characteristics

• Measurements and mechanical principles
• Force, Load, Pressure
• Atmospheric pressure, Absolute pressure
• Force of gravity, Centre of gravity, Specific gravity
• Density, Vacuum, Volumetric efficiency
• Work, Power, Energy
• Pistons - motion, bore, piston displacement
• Compression ratio
• Engine efficiency
• Features of electric motors
• Applied tasks - spark plugs

Lesson 3. Machines and their parts  

• Parts of a machine
• Engine systems
• Lubrication system
• Cooling system
• Fuel system
• Transmission -gearbox, clutch, transmission, drive shaft, PTO
• Power source
• Ignition system - distributor, Coil pack
• Other machines

Lesson 4. Drive Mechanisms -Transmissions, Gears, Belts

• Introduction
• Cog drive machinery
• Belt drive machinery
• Transmission drive machinery
• The transmission system
• Clutch
• Gearbox
• Differential unit
• Applied tasks - replacing drive belts

Lesson 5. Managing Deterioration  

• Splash feed lubrication system
• Pressure system
• Combination pressure and splash
• Oil contamination
• Cooling system - air cooling, water cooling
• Lubrication - oil viscosity
• Types of filter systems
• Materials deterioration
• Properties of materials - metals, non ferrous alloys
• Seals
• Applied tasks: servicing filters

Lesson 6. Optimising Function and Longevity

• Adjustments
• Controlling power
• Carburettors - float system, number of barrels, injectors
• Lubrication
• Exhaust systems
• Catalytic converter
• Muffler
• Extractor
• Turbocharger
• Intercooling, waste gate, blow off valves, twin vs single turbo, boost controller
• Superchargers
• Applied tasks - servicing a carburettor

Lesson 7. Brake Systems

• Introduction
• Drum versus disc brake
• Drum brakes and shoe pad
• Disc brakes
• Pneumatic, Hydraulic and Electric Brakes
• ABS - Anti lock brake system
• Regenerative braking
• Applied tasks - servicing brakes
• Jacking up a vehicle
• Changing disc brakes
• Changing drum brakes
• Motor cycle and push bike brakes

Lesson 8. The Mechanics Workshop – equipment, tools, safety etc  

• Introduction
• Tool maintenance
• Work bench
• Vices and clamps
• Lifts, ramps, jacks, ladders
• Tightening pullers
• Pulleys
• Winches
• Generators, battery chargers
• Cleaning equipment
• Grinders, sharpening equipment
• Work pits, hoists
• Measuring equipment
• Hand tools 
• Spanners and Allen keys
• Pliers and grips
• Screwdrivers
• Files
• Cutting equipment
• Hammers, chisels, punches
• Tap and die cutters
• Lubrication equipment
• Power tools - Drills, saws
• Soldering and welding 

Lesson Aims

• Explain how different types of engines and motors work.
• Describe the features that differentiate the quality and work capacity of engines; one from another.
• Describe the scope and nature of components of a machine.
• Explain different ways of converting the movement of energy to perform useful work tasks.
• Describe how machinery can deteriorate over time, and responses to both prevent and repair deterioration.
• Explain how engines and motors have their power output regulated.
• Explain the mechanisms used to slow or stop any form of motion by applying force.
• Describe machinery workshop tools and equipment, and explain their safe and appropriate use in maintaining and repairing machinery.

LEARN ABOUT SERVICING MOTOR VEHICLES
Some tasks should be attended to more often than others. Engines need water (or a coolant solution) in their cooling system and oil in their lubrication system. Those liquids will diminish over time -faster with more use of the car, faster in older vehicles, faster in some types of vehicles than others. Those liquids need to be checked and topped up at a period appropriate to the machine you are operating. Most Vehicles will come with a log book and service schedule that will outline the time/distance traveled for each component of service.

LEARN ABOUT SERVICING GARDEN EQUIPMENT
The first thing you need to do when undertaking maintenance of your tools is to read any maintenance instructions or manuals supplied with those tools and/or equipment. There may be a regular servicing or maintenance procedure required. When instructions are not supplied then a number of simple maintenance tasks will generally help prolong the life of many power tools.

Tools in good condition are easier and safer to use. Some simple general reminders are listed below:

• Washing - if tools are kept clean they are less likely to corrode or have moving parts seize. This also reduces the likelihood of pests and diseases being spread from infected areas to uninfected areas.
• Make sure all parts of the tool are free of foreign matter or obstructions that may impede the efficient, safe use of that tool.
• Make sure that worn or damaged parts are replaced promptly.
• Make sure that all moving parts are well lubricated.
• Protect (eg. paint or wipe with an oily rag) any parts that are likely to rust or become corroded.
• Keep battery terminals free of corrosion and battery levels topped up.  All connections should be kept tight.
• Make sure any oils are kept topped up, and drained and replaced at regular intervals.
• Keep air cleaners clean and unblocked.
• Keep any cutting edges properly sharpened.
• Periodically check for and tighten any loose nuts, bolts, screws etc.
• Storing   keeping your tools stored properly means they are less likely to be damaged, lost or stolen. 

LEARN TO USE THE RIGHT TOOL FOR THE JOB
Building, maintaining and repairing machinery requires a well organised and equipped workshop. 
Every job you undertake may be achievable with a variety of different tools, but to do the job properly and achieve the best result with the least effort, you should use the best tool for the job and not just an “acceptable compromise”.  

To choose the best tool for any job you need to understand all of your equipment options, the techniques for using that equipment, and what is needed to keep that equipment in good condition.

Consider the following:

• Strong tools will take greater physical stress and handle heavier jobs without breaking (e.g. if you buy a cheap tool built with cheap materials it might not last till the end of the first day, particularly if you are doing heavy work)
• Sharp tools put less stress on the tool and less strain on YOU the user.
• Long handles give you greater leverage and increased reach, putting less strain on your back and other parts of your body.
• When you pay more for a tool, you are usually paying for long hours of thought which have gone into its design. Tools which do the job better and more easily are generally the more expensive ones.
• If your work is heavy, your tools are likely to be strained more  you will need better quality tools.
• Metal tools made with stainless steel or aluminium do not corrode like those made with other metals.