🔧 Machining Skills Progression

A structured approach to learning manual mill and lathe operations

⚙️ Lathe Projects

1Stepped Shaft

Facing Turning Measuring

Turn round stock into 3 different diameters with clean, square shoulders. Aim for ±0.005" tolerance.

2Chamfered & Radiused Shaft

Tool Geometry Compound Slide

Add 45° chamfers and a convex radius. Learn how tool nose radius affects surface finish.

3Hex Bolt

Threading Parting Off Work Holding

Face, turn shank, cut threads with die or single-point, part off. Complete fastener from bar stock.

4Press-Fit Bushing

Boring Internal Tolerances

Turn OD, bore ID to press-fit tolerance (+0.0005" to +0.001" interference). Teaches precision and feel.

5Tapered Handle

Taper Turning Setup Accuracy

Turn a taper using compound slide or tailstock offset. Good test of machine setup skills.

🏭 Mill Projects

1Six-Sided Block

Tramming Indicating Squaring

Square all six faces of rough stock. Opposite faces parallel within 0.001". THE foundational exercise.

2Drilled & Tapped Block

Edge Finding Hole Placement Tapping

Add a bolt pattern to your squared block. Teaches coordinate work and thread cutting.

3Step Block or Vise Jaw

Pocketing Slotting Depth Control

Mill pockets and steps to precise depths. Introduces roughing vs finishing passes.

4T-Slot or Dovetail

Special Cutters Climb Milling

Cut a functional T-slot or dovetail. Teaches cutter selection and surface finish control.

🎯 Combination Projects

Toolmaker's Clamp

Mill Body Turn Screw Threading

Mill the body (slots, flats, holes), turn the screw and swivel pad. Assembles into functional shop tool.

Small C-Clamp

Frame Milling Acme Thread Assembly

Mill frame from flat stock, turn screw with Acme thread, turn swivel foot. Press-fit or thread together.

Bottle Opener

Decorative Turning Lever Geometry

Turn a handle with decorative features, mill the opener flat. Join via threading or pinning.

✅ Skills Checklist

Lathe Operations

Mill Operations

Meta-Skills

🧱 Material Recommendations

Material Forgiveness Notes
6061 Aluminum Very High Great for learning, cheap, fast cuts
12L14 Steel High Free-machining, excellent chip control
1018 Steel Medium Common, teaches proper speeds/feeds
4140 Steel Lower Harder, requires good technique
Brass (360) High Beautiful finish, no cutting fluid needed

⚡ Speeds & Feeds Starting Points

RPM = (SFM × 3.82) ÷ Diameter
Diameter in inches • SFM = Surface Feet per Minute

Lathe (HSS Tooling)

  • Aluminum 300–600 SFM
  • Mild Steel 80–120 SFM
  • Brass 200–400 SFM
  • Stainless 50–80 SFM

Mill (HSS End Mills)

  • Aluminum 300–500 SFM
  • Mild Steel 70–100 SFM
  • Chip Load (Al) 0.001–0.003"
  • Chip Load (Steel) 0.001–0.002"

⚠️ Safety Essentials

🧤
No gloves near rotating machinery — degloving injuries are real and catastrophic
👓
Safety glasses always — chips are hot and sharp, no exceptions
🔑
Remove chuck key immediately — never walk away with it in the chuck
👔
No loose clothing, tie back hair — anything can get caught and pull you in
🛑
Know where the E-stop is — locate it before you start the machine
🚫
Never reach over running spindle — wait for full stop before adjusting

💡 Start with aluminum, go slow, measure often. The goal isn't speed — it's developing feel and understanding the cause-and-effect between your inputs and the cut quality.