T-Levels Engineering, Manufacturing, Processing and Control Flashcards

24 sample cards from the Engineering, Manufacturing, Processing and Control deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. What is 'continuous improvement' (Kaizen)?

   A philosophy of making small, ongoing, incremental improvements to processes, products and working practices, involving everyone in the organisation, to steadily increase quality and efficiency and reduce waste.

2. Compare quality control (QC) and quality assurance (QA).

   QC is reactive — inspecting and testing finished or in-process products to detect defects. QA is proactive — designing and managing processes so that defects are prevented from occurring in the first place.

3. Classify the main categories of manufacturing processes.

   Casting/moulding, forming/shaping (forging, rolling, extrusion, bending), machining/material removal (turning, milling, drilling), joining (welding, brazing, fastening, adhesives), and additive manufacturing (3D printing).

4. What is the difference between subtractive and additive manufacturing?

   Subtractive manufacturing removes material from a workpiece (e.g. machining, cutting) to create a shape; additive manufacturing builds a part by adding material layer by layer (e.g. 3D printing).

5. Compare turning and milling as machining operations.

   In turning the workpiece rotates against a stationary single-point cutting tool (typically on a lathe, for cylindrical parts). In milling a rotating multi-tooth cutter removes material from a stationary or moving workpiece (for flat surfaces, slots and complex shapes).

6. What is the formula for cutting (surface) speed in a machining operation?

   $$v_{c} = \frac{\pi D N}{1000}$$ where $v_{c}$ is cutting speed (m/min), $D$ is diameter (mm) and $N$ is spindle speed (rev/min).

7. Define automation and give the difference between open-loop and closed-loop control.

   Automation is using technology to perform tasks with minimal human intervention. Open-loop control has no feedback — output is not measured or corrected. Closed-loop control measures the output and feeds it back to adjust the input, reducing error.

8. What is a PLC and what is it used for?

   A Programmable Logic Controller — a rugged industrial digital computer used to automate machinery and processes by reading inputs (sensors), executing a control program, and switching outputs (actuators) in real time.

9. In a closed-loop control system, what is meant by 'feedback' and 'error signal'?

   Feedback is the measured value of the output returned to the controller. The error signal is the difference between the desired set-point and the measured feedback value, which the controller acts to minimise: $\text{error} = \text{set-point} - \text{measured value}$.

10. What do the three terms of a PID controller do?

    Proportional (P) responds to the present error, Integral (I) responds to the accumulation of past errors (eliminating steady-state offset), and Derivative (D) responds to the predicted future rate of change of error (damping/stability).

11. What is 'lean manufacturing' and what is its central aim?

    Lean manufacturing is a production philosophy (originating from the Toyota Production System) aimed at maximising customer value while minimising waste — doing more with fewer resources by eliminating non-value-adding activities.

12. Name the seven (classic) wastes identified in lean manufacturing.

    Transport, Inventory, Motion, Waiting, Overproduction, Over-processing, and Defects (remembered by the acronym TIMWOOD).

13. What is 'Just-in-Time' (JIT) production?

    A lean approach where materials and components are produced or delivered only as they are needed in the production process, minimising inventory, storage costs and waste.

14. What do the 5S principles of workplace organisation stand for?

    Sort (Seiri), Set in order (Seiton), Shine (Seiso), Standardise (Seiketsu), and Sustain (Shitsuke) — a method for creating an organised, clean and efficient workplace.

15. Define metrology and distinguish accuracy from precision.

    Metrology is the science of measurement. Accuracy is how close a measured value is to the true value; precision (repeatability) is how close repeated measurements are to each other, regardless of the true value.

16. What is the resolution of a vernier caliper and a micrometer typically used in metrology?

    A typical vernier caliper reads to $0.02\,\text{mm}$, and a standard external micrometer reads to $0.01\,\text{mm}$ (with a vernier scale, $0.001\,\text{mm}$).

17. Compare 'go/no-go' gauges with measuring instruments.

    A go/no-go gauge checks whether a dimension falls within tolerance limits (attribute inspection — pass/fail) without giving a numerical value; a measuring instrument (e.g. micrometer) gives an actual numerical dimension (variable inspection).

18. In engineering drawing, what does 'first-angle' versus 'third-angle' orthographic projection indicate?

    They are two conventions for arranging the views. In first-angle (common in Europe/UK) the view is projected through the object onto a plane behind it; in third-angle (common in the USA) the view is projected onto a plane between the observer and the object. Each has a distinct truncated-cone symbol.

19. What does a tolerance such as $50 \pm 0.05\,\text{mm}$ specify, and what are the limits?

    It specifies the permissible variation in a dimension. The upper limit is $50.05\,\text{mm}$ and the lower limit is $49.95\,\text{mm}$; the total tolerance band is $0.10\,\text{mm}$.

20. What is the difference between clearance, interference and transition fits?

    Clearance fit: the hole is always larger than the shaft (a gap, parts move freely). Interference fit: the shaft is always larger than the hole (press fit, parts are held tight). Transition fit: may result in either a small clearance or small interference depending on actual sizes.

21. Compare planned (preventive) maintenance with reactive (breakdown) maintenance.

    Planned/preventive maintenance is scheduled servicing carried out before failure to prevent breakdowns and extend equipment life. Reactive/breakdown maintenance is carried out after a fault occurs, only restoring function once the equipment has failed.

22. What is condition-based monitoring in maintenance?

    A predictive maintenance technique that monitors the actual condition of equipment using parameters such as vibration, temperature, oil analysis or noise, so maintenance is performed only when measurable indicators show developing faults.

23. Outline a logical sequence for systematic fault diagnosis and rectification.

    Collect evidence/symptoms, analyse and identify possible causes, locate the fault (e.g. half-split/six-point technique), rectify or replace the faulty component, test to confirm the repair, and record the work done.

24. What is the difference between a sensor and a transducer in instrumentation?

    A sensor detects a physical quantity (e.g. temperature, pressure); a transducer converts one form of energy into another — typically converting the sensed physical quantity into an electrical signal that a control system can process. (All sensors that output a signal are a type of transducer.)

What this deck covers

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