Effective Farming Depends upon Making Effective Choices with Machinery and Tools
Develop an ability to manage the selection, operation and maintenance of tools and machinery, with particular reference to agriculture and horticulture.
Learn about the use and operation of tools, equipment and machines.
Machines are powered by engines.
Engines can need a variety of systems to support their operation, including: Cooling systems to stop the engine from overheating; lubrication Systems to prevent wear and tear on moving parts (reduce friction between parts and allow movement with less energy loss); ignition systems provide a spark of electricity to ignite petrol; and transmission systems transmit power/movement from the point of production to the point of use (e.g. Wheels of a tractor).
There are 8 lessons in this course:
Specific Workplace Requirements
Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.
To explain the operation of different types of motors, including petrol and electric engines.
To explain the principles of hydraulics in relation to agricultural and horticultural use.
To explain the operation of the main components of machinery commonly used in agriculture and horticulture including cooling, lubrication, fuel distribution, ignition and transmission systems.
To explain the safe and effective operation of different hand tools commonly used in agriculture or horticulture.
To determine the safe and appropriate operation of power tools in horticultural and agricultural situations.
To explain the safe and appropriate operation of a tractor in horticultural and agricultural situations.
Explain the maintenance procedures for different equipment commonly used in agriculture and horticulture, including hand tools, power tools and tractors.
To determine appropriate equipment for minimum work requirements in an agricultural or horticultural workplace.
An introductory subject which aims to develop an ability to manage the selection, operation and maintenance of tools and machinery - with particular reference to agriculture and horticulture.
Learn the use and operation of tools, equipment and machines.
Learn to Understand Engines
Engines are used all the time on farms (and in other agricultural and horticultural enterprises.
They will usually be driven by either a 2 stroke or 4 stroke engines. Both engines are different types of internal combustion engines. Each of these two types of engines has certain advantages and disadvantages.
They both run by a series of controlled explosions occurring in an “internal” (enclosed) chamber or cylinder. The size of the equipment to be powered will dictate whether you use a two stroke or four stoke engine. Equipment size will also dictate how many cylinders are required. Two stroke petrol engines are used to power smaller equipment like chain saws and small horticultural equipment. Four stoke engines are used for larger equipment and may have one or more cylinders depending the power required.
When an explosion occurs it causes movement in parts of the engine. That movement is translated to a shaft which is caused to turn. As the shaft turns (rotates) it is able to cause something else to turn that does certain work (e.g. turning the wheels of a tractor, the blades of a mower or the parts of a hydraulic pump).
The four stroke engine has one power stroke in every four stokes, and the two stroke has one power stroke in every two strokes. This is explained in more detail later in this lesson. A four stroke is obviously more powerful, but also more expensive and more complex. In a two stroke engine, the intake, exhaust, power and compression strokes of the engine occur in one rotation of the crankshaft.
With a four stroke engine there is more time between this series of events with the crankshaft making two complete rotations for the four stages of one stroke to happen. Two-stroke engines have the advantage over 4-stroke engines by being lighter. They can be used at angles and upside down as there is no oil in the crankcase. A two stroke is however less efficient than 4-stroke engines and requires lubricating oil to be mixed in with the fuel and tends to run less evenly. Two stroke engines usually run at higher speeds than four stroke engines. Four stroke engines have intake and exhaust valves, two stroke engines have intake and exhaust ports.
HOW AN ENGINE WORKS
The Operating Cycle
In any internal combustion engine there are a number of essential parts there are arranged so that a basic series of events occur. This series of events is usually known as the operating cycle.
The internal combustion engine is a form of heat engine. Heat energy, produced by burning fuel within the engine, is changed into mechanical energy. Different types of fuel include petrol, vaporising oil (V.O) or diesel. While different types of fuel are used in different types of equipment, this does not alter the basic operating cycle.
The essential parts of an engine are:
1. The cylinder – fuel is introduced into the cylinder for burning
2. The piston – this moves up and down within the cylinder
3. The cylinder head – this seals off the top of the cylinder
4. The crankshaft – this rotates
5. The connecting rod – connects the piston to the crankshaft
6. The inlet valve – allows entry of fuel into the cylinder
7. the exhaust valve – allows the exit of gases
8. A camshaft – this opens the valves
9. Valve springs – these close the valves
10. The flywheel – this is fitted to the crankshaft to help it rotate
WHY STUDY THIS COURSE?
When you understand engines and the machines they drive; your capacity to use, maintain and even repair that equipment will increase.
Some will undertake this course to fill in what they recognise as a deficiency in their skills set; while others are seeking to build on a very basic understanding which is simply not sufficient for the day to day work in a job they already have or one they hope to get.
Completing this course will increase your knowledge and understanding of machinery and equipment, and enable you to see ways of more efficiently undertaking work on a farm or in the management of other landscapes (natural or man made).