Cutting Aluminum

Assumptions:

• DIY CNC with Makita RT0701C trim router (10,000–30,000 RPM)
• 1-flute O-flute endmill (e.g., ZrN-coated or polished carbide)
• Aluminum 6061
• Air blast or mist coolant recommended
• Rigid fixturing and light cut strategy

1/8” Bit

Parameter	Value
Spindle Speed	20,000–22,000 RPM
Feed Rate	25–35 in/min
Depth of Cut (DOC)	0.010”–0.020” (0.25–0.5 mm)
Width of Cut (WOC)	0.0125”–0.025” (10–20% stepover)
Chip Load	0.0012–0.0018 in/tooth

1/4” Bit

Parameter	Value
Spindle Speed	18,000 RPM
Feed Rate	45–60 in/min
Depth of Cut (DOC)	0.02”–0.04” (0.5–1.0 mm)
Width of Cut (WOC)	0.025”–0.050” (10–20% stepover)
Chip Load	0.0025–0.0035 in/tooth

Tips for Success

• 💨 Coolant: Use compressed air or a mist coolant system to evacuate chips and reduce heat.
• 🧲 Tool Coating: ZrN or polished carbide helps prevent aluminum from welding to the cutter.
• 🧱 Workholding: Ensure aluminum is rigidly clamped to minimize vibration and deflection.
• 🛢️ Lubrication: Apply WD-40 or Tap Magic manually if mist is unavailable.
• ↪️ Entry Strategy: Use ramp or helical entry; avoid plunging directly into the material.
• 👂 Listen and Watch:
  • Squealing = spindle too fast or poor chip evacuation.
  • Gumming = aluminum welding to tool → reduce speed or add lubricant.
  • Chatter = machine flex → reduce DOC or WOC.

    Notes

• These are conservative values for DIY routers. Adjust incrementally once you’re confident.
• Always prioritize chip evacuation — aluminum chips are your biggest enemy.