Composite Prepreg Nesting Yield & CNC Knife Cutting Calculator
Calculate nesting material efficiency, scrap rate, roll length requirements, ultrasonic/oscillating blade scallop pitch, and tangential corner parameters for CNC carbon fiber prepreg, fiberglass, and aramid knife tables (Zünd, Eastman, Gerber, Lectra, Aeronaut).
1. Material & Roll Configuration
2. Ply Geometry & Layup Schedule
3. CNC Knife & Tool Dynamics
Nesting Yield & Cut Quality Metrics
💡 CAM Prepress Tip: For ±45° bias plies, align the DXF primary axis to the fiber grain vector tag. Convert splines to tangential biarcs (G02/G03) with 0.02mm tolerance to eliminate cutter faceting on aerodynamic curved perimeters.
Composite Knife Tooling & Cut Speed Matrix
| Composite Material | Optimal Tool Type | Rec. Feed (mm/s) | Oscillation / Frequency | Corner Radius Overcut Strategy |
|---|---|---|---|---|
| Carbon Prepreg (2x2 Twill / Plain) | Ultrasonic Knife (20/40 kHz) | 300 – 600 | 20,000 – 40,000 Hz | Loop-out or 0.5mm tangential lift |
| Unidirectional (UD) Carbon | Ultrasonic / Electric Oscillating | 200 – 400 | 300 Hz (EOT) / 20 kHz | Tangential blade alignment to prevent fiber splitting |
| Dry Carbon / Fiberglass Woven | Driven Rotary Wheel (PRT) | 400 – 800 | 12,000 RPM (Decagonal) | Point lead-in, avoid sharp inside radius |
| Aramid / Kevlar Fabric | Ultrasonic Knife (Titanium Horn) | 150 – 350 | 20,000 Hz / 40µm Amp | Zero-overcut micro-arc smoothing |
| Core Foam (Divinycell / Rohacell) | Long-Stroke Oscillating (POT) | 100 – 250 | 120 Hz / 7mm Stroke | Bi-arc tangential smoothing, vacuum zone sealing |
1. Tangential C-Axis Knife Rotation
Oscillating and drag knife cutters require the blade edge to point tangentially along the cut vector trajectory. Sharp corners (< 90°) require a controlled blade lift and pivot above the prepreg surface to avoid tearing the tacky resin matrix.
2. Grain Direction Tagging (0° / 90° / ±45°)
Structural composite parts require exact ply orientation. Storefront DXF prepress organizes vectors into distinct CAD layers (`PLY_0DEG`, `PLY_45DEG`, `PLY_90DEG`) with embedded barcode or pen-marking text paths for automated labeling.
3. Scallop Pitch & Delamination Prevention
When cutting with mechanical oscillating knives, scallop pitch ($P = \text{Feed} / \text{Frequency}$) must remain below 0.35 mm. Scallop spacing above 0.5 mm creates jagged sawtooth edges that initiate edge delamination under autoclave curing.
4. Vacuum Hold-Down & Backing Film Integrity
Prepregs with polyethylene or silicone release paper require precise Z-depth control ("kiss-cutting") or sacrificial plastic underlayment to maintain vacuum seal integrity across high-density nested nests.