Engineering

• Ohms law - Voltage/ current = resistance
• Load/Effort = Mechanical advantage
• Velocity Ratio = Distance moved by effort/ Distance moved by load
• Orthographic drawing includes a plan view, end view and a side view
• Volume of a cylinder is pi x r x h$pi r^2 h$
• Area = base x height
• Volume = length x width x height
• Marking includes applying a marking out medium such as engineer’s blue to the material and using a scriber to mark lines for cutting or forming. Dividers and calipers may also be used for marking out. Common tools also used would be engineers square and a steel rule.
• Cutting can occur using a hand tool like a hacksaw, sheers or snips saw or fretsaw, or using machinery such as a metal bandsaw.
• Finishing applications can include oil bluing, lacquer applications, paint, dip coating etc
• Shaping can involve the removal of materials using saws, files or grinding equipment. It is usually applied to change the form/ shape of stock material.
• Drilling is a process whereby a hole is required in a material. Drilling can be done using a hand drill, or drill press/pillar drill, and use a variety of different drill types.
• Milling uses a milling machine to cut accurate features such as; open slots, steps and enclosed slots. It can also be used to face off edges and produce holes.
• Brazing typically involves a brazing hearth to braze metals together to form a permanent joint. The brazing hearth can also be used to heat treat metals by annealing, normalizing, tempering or hardening a range of metals
• Turning uses a machine called a lathe that can be used to turn a piece of metal to create differently shaped round pieces. It can also be used to create threads and to apply different knurled finishes, as well as to apply chamfers or rebates to material.
• Joining metals can be done permanently using welding, brazing, epoxy resin adhesives and soldering. Temporary methods include nuts and bolts, hinges, screws and rivets.
• Soldering is used to heat join softer metals such as silver in jewelry (silver solder) or to attach electronic components to printed circuit boards
• Forming is a process used to change the shape of the material, for example by bending, compressing or extruding. Additional tools such as vices and clamps are often used in this process. Heat is often used to assist forming processes
• Preparing materials includes cutting materials to rough sizes (slightly larger than required) from stock material (the material as purchased from the supplier). Preparation can also consider ensuring that all of the tools and equipment identified in the planning stages is available and ready to use. This can also include undertaking appropriate risk assessment measures to ensure safe working practice is undertaken.
• Identifying potential hazards

  • Visual inspection of the workplace to ensure that no obstructions or hazards are present.

  • Visual inspection of equipment, which includes guards and safety features

  . • Checking of tools to ensure there are no defects or missing parts.
• Undertaking a risk assessment Risk assessments aim to identify potential risks based on the work which will be undertaken during manufacture. The risk assessment will classify the risk according to severity of harm. Once the areas are identified, the likelihood and the control measures are put into place to reduce and minimize the risks from becoming potential accidents to the machinist or operator
• Personal protective equipment (PPE) The risk assessment document should also identify appropriate PPE, which should be used for key equipment and processes.

  For example:

  • ear defenders

  • safety goggles

  • protective aprons

  • heat resistant gloves

  • face shields.
• tensile strength – the ability of a material to resist stretching or breaking when pulled
• compressive strength – a materials ability to withstand loads without changing its shape
• hardness – this is a materials ability to resist changing shape when impacted by another object
• toughness – the ability of a material to absorb energy (impacts) before it starts to deform (change shape)
• malleability – the materials ability to be repeatedly hammered, pressed, bent or rolled into thin sheets
• ductility – the ability of a material to be drawn or plastically deformed without breaking
• conductivity – a measure of how well the material conducts heat or electricity
• corrosive resistance – how well the material can withstand damage caused by chemicals or oxidisation
• elasticity – the ability of a material to limit distorting and return to its original shape and size
• environmental degradation - how the physical environment is degraded, damaged or compromised through a range of situations such as air pollution, water contamination etc.
• Mobile phones

  • compressive strength to resist weight put on the phone casing

  • corrosive resistance to limit damage to the phone casing from chemicals such as hairspray, sun cream or other daily exposures.
• Security alarm

  • compressive strength in its casing to avoid deformation from high winds

  • hardness to avoid possible vandalism or attempts to gain access to the circuit.
• Bicycles

  • ductility to allow the tubular forms of the frame to be created (drawn)

  • toughness to absorb impact, for example when children drop bikes on the floor or during a crash in a race

  • compressive and tensile strength to absorb the shifting weight of the cyclist on the bike.
• Tensile testing - the material or part is clamped in two locations, usually on opposite ends, and increasing pulling force is applied in opposing directions to measure stretching.
• Hardness testing - this is tested by indenting the material with a known hard material such as diamond. The force used to create this is measured to determine hardness
• Toughness testing – this is undertaken by allowing a pendulum with a mass on the base to strike the side of the material or part. The extent to which the shape bends (deflects) dictates its level of toughness.
• Malleability testing is done by applying a stamping action (pressing) on the material to see how much the malleable material will flatten without breaking.
• Ductility testing is performed in a similar manner to tensile strength testing, where the material is drawn apart.