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Activity 001: Machine Identification and Speed Calculation Workshop

Activity ID: U8M1-ACT-001 Duration: 45 minutes Objective: Identify major components of the metal lathe and milling machine, then calculate correct machining parameters for given scenarios.

Overview

Students work in small groups to identify and label all major components of both the metal lathe and the milling machine, then work through a series of speed and feed calculation problems. This activity builds the vocabulary and mathematical foundation needed for all subsequent machining operations.

Materials & Equipment Needed

  • Metal lathe (demonstration unit)
  • Vertical milling machine (demonstration unit)
  • Component identification worksheets (lathe and mill)
  • Speed/feed calculation worksheet
  • Scientific calculator
  • SFM reference chart (provided)
  • Safety glasses

Instructions & Procedure

Phase 1: Metal Lathe Component Identification (12 minutes)

  1. Working in groups of 3-4, identify the following components on the metal lathe:
  2. Headstock, spindle, chuck, gear train
  3. Bed, ways, carriage, saddle
  4. Cross slide, compound rest, tool post
  5. Tailstock, quill, handwheel
  6. Lead screw, feed rod, apron
  7. Threading dial, half-nut lever
  8. Speed selector, feed selector, emergency stop
  9. Record the machine specifications: swing, between centers distance, spindle bore, spindle taper (MT#), speed range, motor HP.
  10. Locate and operate (without cutting): carriage handwheel, cross slide handwheel, compound handwheel, tailstock quill.

Phase 2: Milling Machine Component Identification (12 minutes)

  1. Identify the following components on the milling machine:
  2. Column, base, table, saddle, knee
  3. Spindle, quill, drawbar
  4. X-axis handwheel, Y-axis handwheel, Z-axis (quill feed and knee crank)
  5. Speed selector, feed selector
  6. Table locks (X, Y, Z), power feed controls
  7. R8 collet and drawbar operation
  8. Record specifications: table size, spindle taper, speed range, travel limits (X, Y, Z), motor HP.
  9. Locate the graduated dial collars on each axis. Practice reading them to 0.001" increments.

Phase 3: Speed and Feed Calculations (15 minutes)

Complete the following calculations:

  1. Lathe: Turning 2" diameter mild steel (1018) with an HSS tool. SFM = 90. Calculate RPM.
  2. Lathe: Turning 1" diameter aluminum (6061) with a carbide insert. SFM = 1000. Calculate RPM.
  3. Lathe: Facing 4" diameter brass with carbide. SFM = 600. Calculate starting RPM.
  4. Mill: Using a 1/2" diameter 4-flute HSS end mill on mild steel. SFM = 80. Calculate RPM and table feed rate (IPM) at 0.003 IPT.
  5. Mill: Using a 3/4" diameter 2-flute carbide end mill on aluminum. SFM = 1000. Calculate RPM and table feed rate at 0.005 IPT.
  6. Bonus: For problem #1, if the roughing DOC is 0.050" and feed is 0.010 IPR, calculate the material removal rate (MRR) in cubic inches per minute.

Phase 4: Group Discussion (6 minutes)

  1. What happens if you run significantly above the recommended SFM?
  2. What happens if the feed rate is too low for the speed (rubbing)?
  3. How does workpiece material affect all three parameters?

Discussion Points

  • Why is SFM the starting point, not RPM?
  • How does changing the workpiece diameter on a lathe affect the required RPM?
  • What practical constraints might prevent you from running at the calculated RPM?

Expected Outcomes

  • Students can name all major components of both machines
  • Students correctly calculate RPM from SFM for lathe and mill operations
  • Students can determine table feed rates for milling operations
  • Students understand the relationship between parameters and machining outcomes

Assessment Rubric

Criteria Excellent (4) Proficient (3) Developing (2) Beginning (1)
Lathe Components All components identified correctly 1-2 errors 3-5 errors Cannot identify major components
Mill Components All components identified correctly 1-2 errors 3-5 errors Cannot identify major components
Speed Calculations All problems correct 1 calculation error 2-3 errors Cannot apply the formula
Feed Calculations Correct RPM and IPM for mill problems Minor error in IPM conversion Cannot convert IPT to IPM Cannot calculate feed rates

Safety Considerations

  • Safety glasses are required whenever in the machine shop area
  • Do not operate any machine controls without instructor permission during this activity
  • Keep hands clear of all moving parts, even when the machines are off
  • No loose clothing, jewelry, or long hair around machine tools

Last Updated: 2026-03-19