Lesson Plan

• Describe how material waste is generated in CNC milling and stamping processes.
• Calculate waste fractions using raw and final part volumes.
• Analyse and compare waste‑reduction strategies for each manufacturing method.
• Evaluate the environmental and cost impacts of different waste types.
• Propose practical improvements to minimise waste in a given design.

• Projector and screen
• Worksheet with waste‑calculation tables
• CAD/CAM software demo (e.g., Fusion 360)
• Sample raw blocks (Aluminium 6061, Steel C45)
• Sheet‑metal samples (cold‑rolled steel, Al‑1050)
• Calculator and ruler
• Scrap collection bin for demonstration

Begin with a brief discussion on why reducing waste is crucial for sustainability and profit in manufacturing. Recall students’ prior knowledge of CNC milling and stamping from earlier lessons. Explain that by the end of the session they will be able to calculate waste fractions, compare the two processes, and suggest realistic waste‑reduction measures.

1. Do‑now (5'): Quick quiz on definitions of material waste and its significance.
2. Mini‑lecture (15'): Overview of waste generation in CNC milling and stamping, introduce the waste‑fraction formula with examples.
3. Guided calculation activity (15'): In pairs, students use the worksheet to compute waste fractions from the provided tables.
4. Strategy brainstorming (10'): Groups list waste‑reduction methods for each process and share their ideas.
5. Comparative analysis (10'): Whole‑class discussion comparing waste fractions, environmental impact, and cost implications.
6. Exit ticket (5'): Each student writes one actionable suggestion to reduce waste in either CNC milling or stamping.

Summarise the key differences in waste types and the most effective reduction strategies for CNC milling and stamping. Collect exit tickets to gauge understanding and assign homework: research a real‑world case study where waste was significantly reduced and prepare a brief report outlining the methods used.