Week 7 — Group Assignment: Computer-Controlled Machining
This week group assignment focuses on machine safety.
Instructor Matthew gives us a full train of CNC machine safety check items.
- Instructor's Safety Checklist
- Machine Safety Basics
- Emergency stop location
- Protective guards functional
- Standard operating procedure understood
- Pre-Operation Machine Test
| Check | Verification |
|---|
| Runout | Spindle/tool rotation: no eccentricity |
| Alignment/Fixturing | Workpiece clamped securely, coordinates calibrated |
| Speeds & Feeds | Parameters set for specific material (wood/plastic/modeling board) |
| Materials & Toolpaths | Test cut performed → verify surface quality & dimensional accuracy |
- Essential Cutting Parameters
| Parameter | Unit | Controls | Rule of Thumb |
|---|
| Tool Diameter | mm | Cut width | Larger Ø = wider cut |
| Spindle Speed | RPM | Tool rotation speed | Harder material → lower RPM |
| Feed Rate | mm/min | Tool traverse speed | Balance with spindle speed |
| Depth of Cut | mm | Material removal per pass | Deep cuts → multiple passes |
