CAD Fundamentals: Sketch, Constrain, Model

By the end

What you'll build

• Explain parametric, history-based modelling and design intent, and predict how editing a driving dimension ripples through a feature tree.
• Diagnose whether a 2D sketch is under-, fully-, or over-constrained by counting degrees of freedom, and choose the constraints that remove them.
• Apply the core sketch constraints (coincident, horizontal, vertical, equal, tangent, dimension) to fully constrain real sketches.
• Select and use the right solid feature - extrude, revolve, sweep, or loft - for a given part.
• Build robust feature trees anchored to the origin that survive dimension changes without breaking.
• Model assigned parts in your own free CAD (Onshape free plan or FreeCAD 1.0) and self-verify them against Karka's checkable Volume and Surface-area numbers.
• Read a solid's mass properties (volume, surface area, mass) and relate them to the part's geometry.
• Produce orthographic drawing views in correct first-angle (Indian IS/BIS) projection, and distinguish first-angle from third-angle placement.
• Assemble multiple parts with mates/joints and reason about assembly-level degrees of freedom.
• Complete three guided modelling projects verified by numeric mass-property checks, leaving you with portfolio-ready files.

Curriculum

What's inside

7 modules · 40 lessons

1. 01

   Parametric Thinking

   5 lessons
   • Karka Is the Classroom, Not the CAD Seat
   • Parametric vs Direct: Why CAD Remembers
   • Your CAD Setup and the Mass-Properties Readout
   • Parameters Are Just Arithmeticpython lab
   • Parametric Thinking Checkquiz
2. 02

   Sketches, Constraints & Degrees of Freedom

   7 lessons
   • Sketches, Planes, and the Origin
   • The Constraint Toolbox and Sketch States
   • Constraint Deckflashcard sr
   • Degrees of Freedom: Count and Killsketch lab
   • Fully Constrained: Circles and Tangentssketch lab
   • + 2 more lessons
3. 03

   Core Features: Extrude, Revolve, Sweep, Loft

   7 lessons
   • Extrude: The Workhorse Feature
   • Inspect a Reference Prismmodel viewer
   • Extrude Check: Model and Measure a Blockfill blank
   • Revolve: Anything Round
   • Revolve Check: A Turned Cylinderfill blank
   • + 2 more lessons
4. 04

   Design Intent & Feature Trees

   6 lessons
   • Design Intent: Model So Edits Don't Break
   • The Feature Tree and Parent-Child Relationships
   • Design Intent as Equations: A Bolt Circlepython lab
   • Read the Feature Tree (Error Analysis)quiz
   • Design Intent and Feature-Tree Deckflashcard sr
   • + 1 more lesson
5. 05

   Assembly Basics

   5 lessons
   • Parts vs Assemblies
   • Mates and Joints: Locating Parts, and Assembly DOF
   • Mates and Assembly DOF (Error Analysis)quiz
   • Assembly Mass Checkfill blank
   • Assembly Terminology Deckflashcard sr
6. 06

   Drawings from Models

   5 lessons
   • Orthographic Views and First-Angle Projection
   • From Solid to First-Angle Viewsmodel viewer
   • First-Angle Reading and Drawing Errorsquiz
   • Mass in the Title Blockpython lab
   • Line Types and Projection Symbols Deckflashcard sr
7. 07

   Guided Projects: Model in Your Own CAD, Verified by Numbers

   5 lessons
   • How the Guided Projects Work
   • Project 1 — Spacer Plate (Extrude + Cut)fill blank
   • Project 2 — Stepped Shaft (Revolve)fill blank
   • Project 3 — L-Bracket (Extruded L Profile)fill blank
   • Where You Go From Here

The shape of it

How this course works