What materials can a CNC router cut?

Answer

A CNC router can cut:

 

  • Metals: Aluminum alloy, brass, low-carbon steel (typically <10mm thick);
  • Non-metals: Wood, plastics (ABS, acrylic), composites (carbon fiber), stone, glass, foam;
  • Special materials: PCB, rubber, leather.

Extended Response

I. Working Principle and Scope of CNC Routers

(1) Core Principle
  • Controlled by a computer, a high-speed rotating tool (spindle speed usually 10,000–24,000rpm) moves along X, Y, Z axes for milling, cutting, and engraving.
  • Difference from CNC machining centers: Lower spindle power (2–7.5kW), suitable for rapid processing of thin materials.
(2) Application Scenarios
  • Thickness limit: Metals ≤10mm, non-metals ≤50mm;
  • Precision range: Repeatability ±0.05mm, ideal for medium-precision parts (e.g., signage, furniture components);
  • Efficiency advantage: Planar cutting speed up to 5–10m/min (material hardness-dependent).

II. Classified Materials and Characteristics

(1) Metals
Material Cutting Difficulty Suitable Tools Typical Applications
Aluminum Low Carbide end mill Electronic casings, heat sinks
Brass Medium Diamond-coated tool Decorations, hardware
Low-carbon steel High CBN tool Mold inserts, small structures

 

  • Processing tips:
    • Aluminum requires high speed (18,000–24,000rpm) and high feed (1,000–3,000mm/min) to avoid sticking;
    • Carbon steel needs cooling (e.g., emulsion) to prevent tool overheating.
(2) Wood and Composites
Material Cutting Features Tool Selection Surface Quality
Solid wood Possible grain cracking Spiral-edge mill Grain-aligned cut Ra≤6.3μm
Plywood Interlayer delamination Double-edge mill Sanding required
Carbon fiber Hazardous dust, fiber breakage Diamond saw blade Edge deburring needed

 

  • Process optimization:
    • Dry solid wood to 8%–12% moisture content to reduce warping;
    • Use compressed air for carbon fiber dust collection, negative-angle tools to minimize delamination.
(3) Plastics and Rubber
Material Thermal Deformation Risk Tool Requirements Typical Applications
ABS Medium Sharp single-edge mill Models, toys
Acrylic High Diamond-coated tool Transparent panels, crafts
Silicone Extremely high Cryogenic cutting (LN₂) Seals, medical molds

 

  • Temperature control:
    • Acrylic cutting speed ≤3m/min, spindle 20,000rpm to prevent edge melting;
    • Silicone requires liquid nitrogen cooling to -196℃ for brittle fracture.
(4) Stone and Glass
Material Mohs Hardness Tool Selection Cutting Thickness Limit
Marble 3–4 Diamond saw blade ≤30mm
Granite 6–7 Resin-bonded grinding wheel ≤20mm
Glass 6.5–7 Laser-assisted cutting ≤10mm

 

  • Processing challenges:
    • Stone cutting needs continuous water cooling to prevent dust inhalation;
    • Glass requires pre-scoring + stress separation, CNC suits simple shapes only.

III. Cutting Parameters Comparison

(1) Spindle Speed and Feed Rate
Material Spindle Speed (rpm) Feed Rate (mm/min) Cut Depth (mm)
Aluminum 18,000–24,000 1,000–3,000 1–3
Wood 12,000–18,000 3,000–8,000 5–10
Acrylic 15,000–20,000 500–1,500 0.5–2
Carbon fiber 10,000–15,000 300–800 0.3–1
(2) Tool Type Selection
  • Flat end mill: For planar milling and contour cutting;
  • Ball nose mill: For 3D surface engraving (e.g., relief);
  • V-bit: For text engraving on signs (30°–90° angles).

IV. Common Issues and Solutions

(1) Metal cutting
  • Issue: Rapid tool wear, rough surface;
  • Solution: Use coated tools (e.g., TiAlN), increase coolant pressure (≥2MPa).
(2) Wood cutting
  • Issue: Tearing, charring;
  • Solution: Reduce feed speed (<5m/min), use tools with ≥45° helix angle.
(3) Plastic cutting
  • Issue: Burring, slagging;
  • Solution: Tool edge radius <0.01mm, cutting speed >15m/min.
(4) Composite cutting
  • Issue: Delamination, fiber pull-out;
  • Solution: Use diamond grinding heads, spindle speed ≥18,000rpm, cut depth ≤0.5mm.

V. Industry Application Cases

(1) Furniture manufacturing
  • Material: MDF, solid wood;
  • Process: Grooving, engraving, mortise-tenon machining;
  • Efficiency: 20–30 wardrobe door panels (with carvings) in 8 hours.
(2) Advertising signage
  • Material: Acrylic, PVC, aluminum sheet;
  • Process: Cutting, hollowing, 3D engraving;
  • Precision: Minimum text width 0.8mm, depth adjustable 0.1–3mm.
(3) Automotive interiors
  • Material: Carbon fiber, leather, foam;
  • Application: Dashboard molds, seat brackets;
  • Technology: 5-axis cutting for complex surfaces (e.g., steering wheel covers).
(4) PCB manufacturing
  • Material: FR-4 fiberglass board;
  • Process: Edge milling, drilling (hole diameter ≥0.3mm);
  • Precision: Line width tolerance ±0.05mm, suitable for prototyping.

VI. Equipment Selection and Material Matching

(1) Choose spindle power by material hardness
Material Type Recommended Spindle Power (kW) Suitable Tool Diameter (mm)
Soft materials (wood, foam) 2.2–3.7 3.175–12.7
Metals (aluminum, copper) 4.5–7.5 6–16
Hard materials (stone, glass) 7.5–11 6–20
(2) Choose Z-axis stroke by cutting thickness
  • Thin materials (≤10mm): Z stroke 50–100mm;
  • Medium-thick materials (10–50mm): Z stroke 150–200mm;
  • Special needs (e.g., stone carving): Z stroke ≥300mm.
(3) Dust collection system
  • Wood/plastic cutting: Pulse bag dust collector (airflow ≥3000m³/h);
  • Metal cutting: Oil mist collector (filtration ≥0.3μm);
  • Composite cutting: Three-stage filtration (primary + medium + HEPA).

VII. Future Technological Trends

(1) Laser-assisted CNC cutting
  • Glass/ceramic: Laser pre-heating reduces brittleness for precise contours;
  • Efficiency: 3–5x faster than traditional mechanical cutting.
(2) Intelligent tool compensation
  • Real-time tool wear monitoring via sensors, automatic parameter adjustment;
  • Tool life prediction accuracy ±5%, reducing downtime.
(3) Multi-material composite processing
  • Single machine compatible with metal, plastic, wood (e.g., Mazak VARIAXIS i-300A);
  • Changeover time <5 minutes, ideal for small-batch, multi-variety production.

Conclusion

CNC routers can cut metals, non-metals, and special materials, but tooling, parameters, and equipment must align with material properties. Metal cutting requires focus on tool life, wood on surface quality, plastics on thermal deformation, and composites on delamination. Future technologies like laser assistance and intelligent compensation will further expand material adaptability and processing efficiency.

Recommended Reading