SOLIDWORKS Design Approach · Part 01
Most CAD training teaches menus. This series teaches decisions. It treats a modern parametric modeller as an engineering system whose commands are only the visible surface of a much deeper set of geometric, dimensional and manufacturing choices.
Executive summary
A designer who knows every command in a CAD system and nothing about design intent will produce models that break the first time a dimension changes. A designer who understands topology, parametrics, tolerance behaviour and manufacturing constraint will produce robust models in almost any system, because the concepts transfer and the keystrokes do not.
That is the organising principle of this series. Each part starts with an engineering task and works backwards to the modelling technique that serves it, rather than starting with a toolbar and looking for something to apply it to. SOLIDWORKS is used throughout as the reference implementation because its feature tree makes modelling decisions unusually visible — the tree is a readable record of how a designer chose to build a part.
Position
Four claims sit underneath every page that follows.
Before any sketch is drawn, a part can be read for geometric clues: is it an extrusion, a revolve, a composite, or genuinely free-form? Is it symmetric? Does it contain patterns? Those clues determine the fastest build, the most editable build, and the build that matches how the part will actually be made. Those three are not always the same, and choosing between them is an engineering judgement.
Parametric modelling separates the shape from its size. A sketch is a set of parameters and relations; dimensions are simply the values currently assigned to them. Once that distinction is internalised, a designer stops treating a model as a drawing and starts treating it as a small, editable program that produces geometry.
The feature tree is documentation whether or not anyone intends it to be. The order in which features are created, the references they are attached to and the relations that lock their sketches encode the reasoning behind the design. Well-built models absorb change; poorly built models fail on it.
Geometry that cannot be machined, moulded, bent or printed is not a design, it is a picture. Tolerances, draft, wall thickness, tool access and material selection belong in the modelling conversation from the beginning, not in a review after the model is finished.
Structure
Five stages, each building on the last. The first two establish the language; the remaining three extend it into geometry, verification and production.
Process context, the working environment, model topology, parametrics, sketching discipline and design intent — the conceptual base that makes everything else legible.
Features, automation, drawings, assemblies and visual communication: the day-to-day production work of a design office.
Curves, surfaces, sheet metal, weldments and sustainable design — where mathematics and material behaviour enter the model.
Tolerancing, data exchange and analysis tools: proving that a design will function, transfer and be inspectable before anything is cut.
Rapid prototyping, numerical control machining and injection moulding — the routes from a validated model to a physical part.
The pathway is designed to be read in sequence, but the later stages are largely self-contained. A reader who already models confidently can begin at Part 11 (curves) or Part 15 (tolerances) without loss. Parts 02 to 05 are the exception: almost everything later assumes the vocabulary they establish.
Framework
Nearly all mainstream parametric systems present the same three document types. Understanding what each one owns removes most beginner confusion.
The three are associative: a change made in one propagates to the others. That associativity is the single most valuable property of a parametric system and the single most common casualty of careless modelling. Much of this series is, in effect, about protecting it.
Audience and scope
Practitioners who model daily and want a firmer conceptual footing under their habits, particularly around tolerance behaviour and manufacturability.
Anyone producing drawings to ASME or ISO conventions who needs the reasoning behind the drafting rules rather than a list of them.
Readers building CAD literacy from the ground up, including those preparing for vendor certification.
Metric units lead throughout, with imperial equivalents where industry practice still favours them — sheet gauge and many machining conventions, for example. Australian English is used for all narrative text; software command names, standard designations and code words are reproduced in their published form.
Series
The SOLIDWORKS Design Approach series works through computer aided design as an engineering discipline, from first principles to manufacture.
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