Knowledge of machines CMT 7-6

• Indicators
• Progression
• Teacher guidance
• Contexts for teaching and learning
• Assessment for qualifications

Machines consist of fixed and moving parts that modify mechanical energy and transmit it in a more useful form. A simple machine, such as a lever, a pulley, or an inclined plane, alters the magnitude or direction, or both, of an applied force. Complex machines have internal energy systems, such as electric motors, steam engines, turbines, combustion engines, solar energy systems, nuclear systems, that combine with levers, inclined planes and/or screws to enable the machine to perform their intended function/s.

Learning objective: CMT 7-6

Indicators

Students can:

• describe the efficiencies of machines in relation to their safe application
• explain how mechanical components combine to provide the desired mechanical advantage, and relative motion between input and output in a range of machines
• discuss why mechanical components were combined to provide the mechanical advantage, relative motion between input and output, and efficiency desired in a range of machines.

Progression

At level 6, students learn about simple machines such as levers, inclined planes and screws, and how when combined with mechanical components they are able to achieve a mechanical advantage and motion. This should progress to students at level 7 learning how to explain the functionality of machines using technical language, diagrams and symbols.

Teacher guidance

To support students to understand advanced concepts related to machines at level 7, teachers could:

• provide opportunity for students to explore efficiencies of machines (for example, block and tackle, chain block, pneumatic or hydraulic jack, and turntable) and explain their safe use 
• show that these machines should include two or more mechanical components (for example, cams and followers, pivots and linkages, gears, belt or chains and sprockets, shafts and bearings)  
• guide students to explain how mechanical components combine to provide the desired mechanical advantage, and relative motion between input and output in a range of machines 
• guide students to discuss, for a range of machines, how mechanical advantage was obtained by combining mechanical components, the relative motion between input and output for the machines, and efficiency(s) obtained (note: a machines efficiency is determined by the ratio of the energy delivered (or work done) by a machine to the energy needed (or work required) to operate it (output energy/input energy).

TOP

Contexts for teaching and learning

This learning objective is a knowledge objective and hence there is no requirement for students to actually construct the machine(s) they are studying. However, within a programme of work it would be possible to tie the knowledge related to this learning objective with a project where students are actually designing and/or constructing an outcome that involves a machine or is a complete machine. Knowledge of machines could be covered before students design and make their own technological outcome that includes parts of or a complete machine. For example, students could construct a wind generator or a radio control car.

For this objective a machine will include two or more mechanical components. Examples of machines may include but are not limited to: block and tackle, chain block, pneumatic or hydraulic jack, and turntable. Examples of mechanical components include:

• cams and followers – may include but are not limited to: cams such as plate and eccentric; followers such as needle, roller, flat, and offset
• pivots and linkages – may include but are not limited to: pivots such as fixed and moving; linkages such as parallel, reverse, and sliding crank motion
• gears may include but are not limited to: spur, bevel, helical, rack and pinion, worm, and idler
• belt or chains and sprockets may include but are not limited to: flat belt, v-belt, duplex chain or double belt, and tooth belt
• shafts and bearings may include but are not limited to: solid shafts, hollow shafts, ball bearing, roller bearing, and conical bearing.

Students will need to learn about and investigate a range of machines, and collect evidence that explains:

• how they combine mechanical components to transfer work and motion between inputs and outputs, and achieve mechanical advantage 
• how they obtain desired efficiencies in relation to their safe application.

This evidence could include annotated sketches, mock-ups, models, photographs, quotes, and video clips.

Demonstrate understanding of advanced concepts relating to any machines used in the manufacturing and technology sector; for example, aeroplanes and their associated machinery, machines used for assembly of electronics or machines used in food technology, sewing machines, machines used in the construction and infrastructure sector, for example, engineering, heavy machine operating, landscape construction, plumbing, roading construction or roofing and workshop machines.

• The teaching and learning programme could incorporate a variety of activities such as:
  • A site visit(s)
  • Futrureintech ambassador or other guest speakers
  • Case studies, technical manuals and books relating to how machines work and internet research
  • Deconstructing and experimenting with existing machine and components
  • Using simulation and virtual machines to explore functionality

Literacy considerations

• To be successful, students will need to understand the assessment language of describe, explain and discuss. Note the following definitions:
  • to identify is to state an idea
  • to describe is a statement that gives details about the outcome or idea
  • to explain is to describe in detail with reasons – often including the how and why
  • to discuss requires an explanation that is comprehensive, detailed, broad and shows evidence of some complexity in thinking. It may be a reasoned argument presenting a particular point of view, a comparison and contrast between two ideas or concepts, or it may be  a detailed reasoning and relationship between several complex ideas.
• Students will need to be supported in their understanding of how describe, explain, and discuss look when collecting their evidence for assessment and writing (frames and structures or templates can be used judiciously to support this). Care must be taken not to over template writing forms, which may not allow students to achieve against the criteria.

Students will need to understand the following:

• A machine will include two or more mechanical components. Examples of machines may include but are not limited to: block and tackle, chain block, pneumatic or hydraulic jack, and turntable.
• Mechanical components include:
  • cams and followers may include but are not limited to: cams such as plate and eccentric; followers such as needle, roller, flat, and offset
  • pivots and linkages may include but are not limited to: pivots such as fixed and moving; linkages such as parallel, reverse and sliding crank motion
  • gears may include but are not limited to: spur, bevel, helical, rack and pinion, worm, and idler
  • belt or chains and sprockets may include but are not limited to: flat belt, v-belt, duplex chain or double belt, and tooth belt
  • shafts and bearings may include but are not limited to: solid shafts, hollow shafts, ball bearing, roller bearing, and conical bearing.
• A machine’s efficiency is determined by the ratio of the energy delivered (or work done) by a machine to the energy needed (or work required) to operate it (output energy/input energy).

Students will need to be able to:

• explore, research, and gather information related to advanced concepts relating to machines
  • explaining how mechanical components are combined to form machines
  • describing the efficiencies of machines in relation to their safe application
  • explaining how mechanical components are combined to transfer work and motion in machines
• explain efficiencies of machines (for example, block and tackle, chain block, pneumatic or hydraulic jack, and turntable) and their safe use, explaining how mechanical components combine to provide the desired mechanical advantage, and relative motion between input and output in a machine 
• use technical language, diagrams, and symbols to explain how machines work
• evaluate and present evidence to demonstrate their understanding.

Resources to support teaching and learning

• Introductory section of the senior secondary teaching and learning guide for technology
• Safety in Technology Education: A Guidance Manual for New Zealand Schools
• Indicators of progression:
  • Knowledge of machines
  • Construction and mechanical technologies
  • Indicators of progression for technology
  • Indicators: Learning objectives

Other resources

Culley, R. (ed). (1977). Fitting and Machining. TAFE Publications Unit.

Pedersen, G. (2011). Kontiki Fishing. The Shed,December 2011–January 2012.

Operator manuals for milling machines:

• 2.1 Machine Tool Basics – Milling machine operations. SMITHY GRANITE 3-in-1
• 2.2 Machine Tool Basics – Mill cutting tools operations. SMITHY GRANITE 3-in-1
• 2.3 Machine Tool Basics – Mill workholding tools. SMITHY GRANITE 3-in-1
• 2.4 Machine Tool Basics – Milling controls. SMITHY GRANITE 3-in-1
• Crash course in milling: Chapter 1 – Basic Machine Anatomy. Glacern machine tools
• Crash course in milling: Chapter 2 – Basic Machine Operation. Glacern machine tools
• Home built milling machine
• LEGO 3D milling machine carves floral foam into 3D shapes
• Milling machine setup – Crash course in milling

TOP

Assessment for qualifications

The following achievement standard(s) could assess learning outcomes from this learning objective:

• AS91349 Construction and mechanical technologies 2.25: Demonstrate understanding of advanced concepts related to machines

Key messages from the standard

The teacher may select or negotiate with students a suitable machine for them to investigate. The machine could be one that a student(s) has designed and/or manufactured, or one selected by teacher and or students.

For this achievement standard a machine will include two or more mechanical components. 

For this standard, students should explore and investigate the selected machine(s) or components and demonstrate their understanding of:

• the components and their functions within machines 
• how to use technical language, diagrams, and symbols to explain how machines work
• how required energy efficiencies are obtained for machines, and how this impacts on a machine’s energy system.

Mechanical components include:

• cams and followers may include but are not limited to: cams such as plate and eccentric; followers such as needle, roller, flat, and offset
• pivots and linkages may include but are not limited to: pivots such as fixed and moving; linkages such as: parallel, reverse and sliding crank motion
• gears may include but are not limited to: spur, bevel, helical, rack and pinion, worm, and idler
• belt or chains and sprockets may include but are not limited to: flat belt, v-belt, duplex chain or double belt, and tooth belt
• shafts and bearings may include but are not limited to: solid shafts, hollow shafts, ball bearing, roller bearing, and conical bearing.

A machine’s efficiency is determined by the ratio of the energy delivered (or work done) by a machine to the energy needed (or work required) to operate it (that is, output energy/input energy).

Resources to support student achievement

• Achievement standard
• Clarifications document
• Conditions of assessment and assessment resources 

Last updated November 24, 2023

TOP