Engineering Graphics, CAD and Technical Communication
Technical drawing communicates design unambiguously. Candidates must understand orthographic projection (first-angle vs third-angle - Australia uses third-angle), isometric views, sectional views, and standard symbols. Know dimensioning rules: dimensions should not be duplicated, should be placed on the most descriptive view, and should reference features clearly. Understand line types: visible (continuous thick), hidden (dashed), centre (chain), dimension/extension (thin).
CAD concepts: parametric modelling, constraints, layers, model space vs paper space, and the value of revision control. Know the difference between sketch (2D profile) and feature (extrude, revolve, fillet). Communicate through drawing standards (AS 1100 in Australia), tolerances, and surface finish symbols. Technical reports should include title, purpose, method, results, discussion, and references.
Traps
First-angle vs third-angle placement of views is a common error - third-angle places the top view above the front view. Hidden lines should be omitted where a section clarifies. Over-dimensioning creates conflict. CAD models are only as good as their constraints - under-constrained sketches change unexpectedly.
Worked rule of thumb
For third-angle projection: the view is placed on the same side as it is viewed from. Front view centre; top view above; right-side view to the right. If a hole appears circular in the front view, it appears as a rectangle with hidden lines in the top view.