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Slide 001: CAD to CAM Workflow Overview

Slide Visual

CAD to CAM Workflow Overview

Slide Overview

This slide introduces the complete digital workflow from design concept to physical cut. Students will understand how CAD and CAM software work together, what file formats are involved, and where human decisions are critical in the pipeline.

Instruction Notes

The Digital Fabrication Pipeline

The CNC workflow has distinct stages, each requiring different software and skills:

Stage 1: Design (CAD) Create 2D profiles or 3D models using Computer-Aided Design software. For CNC routing, common inputs include: - 2D vector files: DXF, SVG, AI (for profile cuts, pockets, engraving) - 3D models: STL, STEP, IGES, Fusion 360 native (for 3D contour cutting) - Common CAD tools: Fusion 360, FreeCAD, Inkscape (2D), VCarve Pro (integrated)

Stage 2: CAM Programming Import the design into CAM software and define how the machine will cut it: - Select tool (bit type, diameter, flute count) - Define operations (profile, pocket, drill, 3D contour, V-carve) - Set cutting parameters (feed rate, spindle speed, stepdown, stepover) - Configure workholding avoidance zones - Add tabs/bridges for through-cuts - Popular CAM software: Fusion 360 CAM, VCarve Pro, Carbide Create, EstlCAM

Stage 3: Post-Processing The CAM software generates a generic toolpath internally. The post processor translates this into machine-specific G-code: - GRBL post processor for Shapeoko, X-Carve, OpenBuilds machines - Mach3/Mach4 post processor for Mach-controlled machines - LinuxCNC post processor for LinuxCNC-based systems - Incorrect post processor selection causes errors, crashes, or unexpected behavior

Stage 4: Transfer & Execution G-code is loaded into the machine controller software (UGS, CNCjs, Carbide Motion, Mach4). The operator: - Previews the toolpath visualization - Sets work zero on the physical machine - Runs the job with appropriate feed rate override

Critical Decision Points

The human operator makes decisions at every stage that affect quality and safety: - Design: Tolerances, fillet radii (must be ≥ tool radius for inside corners) - CAM: Tool selection, speeds/feeds, depth strategy - Setup: Workholding method, material orientation, zero position - Execution: Feed override, visual/audio monitoring

Common Mistakes

  • Inside corners designed sharper than the tool radius — impossible to cut
  • Forgetting to account for tool diameter in pocket dimensions
  • Using the wrong post processor — can cause axis inversions or unit errors
  • Not simulating before cutting — leads to clamp collisions or air cutting

Key Talking Points

  1. CAD defines WHAT to make; CAM defines HOW to make it
  2. The post processor is the translator between CAM and your specific machine
  3. Every step in the pipeline requires human judgment — it is not fully automated
  4. Simulation is your last chance to catch errors before they become broken bits
  5. Inside corner radius must always be ≥ tool radius

Learning Objectives (Concept Check)

  • [ ] Describe the four stages of the CAD-to-CNC pipeline
  • [ ] Explain the purpose of a post processor and why the correct one matters
  • [ ] Identify at least 3 critical decisions the operator makes during CAM programming

Last Updated: 2026-03-19