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Module 4: Precision Measurement & Safety

Overview

This module covers precision measurement techniques essential to verify that finished parts meet specifications, machine safety (entanglement prevention, guarding, lockout-tagout), and proper handling of coolants and chips. Measurement is the foundation of quality control; understanding measurement uncertainty and tolerance stacks is critical.

Learning Objectives

  1. Use dial calipers to measure outside dimensions to ±0.001"
  2. Use outside and inside micrometers to measure to ±0.001"
  3. Use dial indicators to verify flatness, runout, and alignment
  4. Understand measurement uncertainty and resolution
  5. Calculate and apply tolerances (limits, fits)
  6. Recognize hazards of entanglement (rotating spindle, chuck, rotating cutters)
  7. Properly use quill handle and understand safety interlocks
  8. Apply proper lockout-tagout (LOTO) procedures
  9. Handle cutting fluid safely (skin irritation, disposal)
  10. Manage chip evacuation safely (never use hands; always use chip brush)

Module Structure

  • Slide 1: Precision Measurement (Calipers, Micrometers, Dial Indicators)
  • Slide 2: Measurement Uncertainty & Tolerance Application
  • Slide 3: Machine Safety (Entanglement, Guard Design, Quill Handle)
  • Slide 4: Lockout-Tagout (LOTO) & Energy Control
  • Slide 5: Chip & Coolant Management, First Aid

Assessment

  • Practical measurement: Measure test parts with calipers and micrometer
  • Verification: Check part dimensions against tolerance specification
  • Safety scenario: Respond to entanglement hazard or coolant splash
  • LOTO demonstration: Demonstrate proper lockout procedure (with supervision)
  • Chip management: Show safe chip evacuation using brush (not hands)

Time Allocation

  • Instructor Delivery: 2.5 hours
  • Hands-on Measurement Practice: 2.5 hours
  • Safety Training & Scenario Response: 2 hours
  • Assessment: 1 hour
  • Total Module Time: 8 hours

Prerequisites

  • Modules 1–3 (lathe and mill operations; need parts to measure)

Resources

  • Precision measuring tools:
  • Dial calipers (standard and vernier)
  • Outside micrometer (0–1", 1–2" ranges)
  • Inside micrometer
  • Depth gauge
  • Dial indicator with magnetic base
  • Test parts (completed lathe/mill projects)
  • Tolerance specification references (ANSI B4.4M)
  • Cutting fluid SDS (Safety Data Sheet)
  • Lockout-tagout kit (padlocks, hasp, tags)
  • First aid kit with burn treatment and skin irritant relief
  • Chip brush, proper bin for chip disposal
  • Safety glasses, hearing protection, nitrile gloves for coolant handling

Module Version: 1.0 Created: 2026-03-15