Course 4 | Foundation
Engineering Graphics and CAD
Communicate mechanical geometry precisely and build robust parametric models others can manufacture, inspect, and change. Thirty-five modules take you from a first sketch to a complete, reviewed design package, grounded in ISO conventions and taught with Onshape.
Course snapshot
- Purpose
- CAD is the communication system for geometry, fit, tolerances, manufacturing, and design decisions.
- Prerequisites
None
- Next in the guided sequence
- Used in Career Directions
How to study this course
- Sketch
- Constrain
- Dimension
- Model
- Inspect design intent
- Create drawing
- Check manufacturability
How this course is designed
See before you draw
Visualization and projection come first, so that when CAD arrives it expresses geometry you already understand. You learn why a view is chosen and why a sketch is constrained, not just which button to press.
Standards and judgement
ISO conventions (128, 129-1, 286, 1101) are taught at an introductory level, always distinguishing a simplified teaching rule from the full standard, with worked examples whose numbers are verified.
Built toward manufacture
The arc runs from sketch to toleranced drawing to robust model to a manufacturability review, the exact base that Manufacturing Processes and Machine Elements (both of which require this course) assume.
The 35 modules, in six parts
Part I · Visual communication foundations
01 | Module
Graphics as the language of engineering
Why a drawing defines a part, and pictorial versus multiview.
02 | Module
Freehand technical sketching and proportion
Blocking-in, proportion, and deliberate line weight by hand.
03 | Module
Spatial visualization and mental rotation
Rotating objects in the mind and reading ambiguity.
04 | Module
Pictorials: isometric and oblique
Single-view 3D and where each pictorial fits.
05 | Module
Orthographic projection and projection angle
The glass box, six views, first versus third angle.
06 | Module
Choosing and reading views
Minimum views and reconstructing a missing one.
07 | Module
Line conventions and drawing organization
The ISO 128-2 line alphabet and sheet layout.
Part II · Internal and inclined geometry
08 | Module
Section views: cutting planes and hatching
Revealing internal geometry by cutting the part.
09 | Module
Section types and conventions
Full, half, offset, and the rib non-sectioning rule.
10 | Module
Auxiliary views and true shape
The true shape of inclined faces.
Part III · Dimensioning and technical definition
11 | Module
Dimensioning principles (ISO 129-1)
Placing size and location clearly and legibly.
12 | Module
Functional, non-redundant dimensioning
Datums, chain versus baseline, and tolerance stack-up.
13 | Module
Tolerances and dimensional variation
Limits, tolerance, and the cost of tightness.
14 | Module
Limits and fits: holes and shafts (ISO 286)
Clearance, transition, and interference fits.
15 | Module
Datums and geometric tolerancing (ISO 1101)
Controlling form, orientation, and location.
16 | Module
Surface texture, threads, and features
Finish, ISO threads, and standard hole callouts.
17 | Module
Reading and inspecting a part drawing
Systematic reading and defect hunting.
Part IV · Parametric CAD foundations
18 | Module
CAD data, coordinates, and modelling strategy
What a parametric model is, and planning before modelling.
19 | Module
Sketch planes, references, and entities
Choosing planes and drawing clean sketches.
20 | Module
Constraints and fully constrained sketches
The core CAD skill: geometry with zero degrees of freedom.
21 | Module
Solid features: extrude, revolve, hole, fillet
The core feature set and robust end conditions.
22 | Module
Patterns, mirrors, and repeated geometry
Parametric repetition that updates together.
23 | Module
Feature order, design intent, robust models
Models that survive change.
Part V · Parts, assemblies, and drawings
24 | Module
Multi-feature parts and mating geometry
Real parts and the interfaces where they meet.
25 | Module
Assemblies: structure and mates
Joining parts with mates that match real joints.
26 | Module
Degrees of freedom, interference, clearance
Verifying that an assembly moves and fits.
27 | Module
Exploded views and bills of materials
Communicating an assembly and its parts.
28 | Module
Drawings from CAD
Standards-compliant drawings straight from a model.
29 | Module
Revisions, versions, and engineering change
Managing change with traceability.
Part VI · Manufacturability and engineering judgement
30 | Module
Modelling machined parts
Machinable geometry and process limits.
31 | Module
Sheet-metal and fabricated parts
Constant thickness, bends, and flat patterns.
32 | Module
Additive-manufacturing considerations
Layers, overhangs, and print orientation.
33 | Module
Design for assembly; recognizing bad geometry
DFA and spotting impossible or ambiguous geometry.
34 | Module
Reviewing a model and drawing
The four-domain engineering review.
35 | Module
Final integrated project
The whole course on one original mechanism.