CNC Foam Cutting & Packaging

CNC Hot Wire Foam Cutting Calculator

Calculate radiant melt kerf width ($K$), toolpath vector offset ($d_{\text{off}}$), catenary center wire drag lag ($\delta_{\text{lag}}$), and corner feed deceleration limits for 2-axis and 4-axis synchronized hot wire CNC cutting.

1. Input Parameters

Foam Material & Density:

Substrate density and melting characteristics.

Hot Wire Diameter (d_w in mm):

NiChrome, Rene 41, or Titanium cutting wire diameter.

Wire Operating Temperature (T_w in °C):

Radiant cutting temperature of the electrically energized wire.

Cutting Feed Rate (F in mm/min):

CNC axis linear traversal velocity through the foam billet.

Wire Span Length (L in mm):

Unsupported distance between CNC cutting carriage gantry arms.

Spring / Pneumatic Wire Tension (T in N):

Mechanical pre-tension applied to minimize thermal wire sag and lag.

2. Calculation Results

Radiant Kerf Width (K)

1.48 mm

Half-Kerf Offset (d_off)

0.74 mm

Centerline Wire Drag Lag

1.85 mm

Corner Decel Min Radius

3.70 mm

3. Geometric Visualizer

Tooling & Vector Prepress Engineering Notes

CNC Hot Wire Foam Cutting Physics: Hot wire cutting does not rely on mechanical contact; rather, radiant thermal energy melts a vaporized channel ahead of the moving wire. The total kerf width ($K$) and wire drag lag ($\delta_{\text{lag}}$) depend on feed speed, radiant heat, and mechanical wire tension:

K = d_w + C_foam × [(T_w - T_melt) / √F] [mm]
δ_lag = (F_drag × L²) / (8 × Tension) [mm]

Vector Prepress Offsetting: Apply a continuous outward/inward half-kerf offset ($d_{\text{off}} = K / 2$) to all architectural molding and wing rib profiles. For sharp 90° corners, program corner loop overtravels or dwell pauses to allow the wire center lag to catch up before changing direction.