Technical Drawing, Communication and Modelling
Drawing conventions
Candidates must read and produce orthographic projections (front, plan, side views in first- or third-angle), isometric drawings, and exploded views. Know line conventions: continuous thick for outlines, continuous thin for dimension and projection lines, dashed for hidden detail, chain lines for centrelines and cutting planes. Understand dimensioning rules - dimensions outside the outline, consistent units, no repeated dimensions, and tolerances stated where needed.
Communication and modelling
Know how designers communicate: sketches, working drawings, assembly drawings, flow charts, and digital tools such as CAD and 3D modelling. Understand physical modelling (card, foam, clay, prototypes) and its purpose - testing ergonomics, form and function before manufacture. Know the difference between a scale model, a mock-up and a prototype.
Common traps
Questions often test first-angle versus third-angle placement of views, or confuse hidden detail with centre lines. Another trap is treating a drawing as decoration rather than a precise instruction set; missing dimensions make a drawing unmanufacturable.
Worked rule of thumb
Apply S-F-P when reading an orthographic set: Size (overall dimensions), Features (holes, slots, radii), Position (where features sit relative to datums). Any missing item is a drawing error to flag.