Parametric Living Hinge (Laser Kerf-Bending Lattice) SVG & DXF Generator
Parametric Living Hinge (Laser Kerf-Bending Lattice) SVG & DXF Generator
- PASSClosed Outer Contours: 1 closed LWPOLYLINE cut loop(s) verified
- PASSZero Duplicate Cut Paths: 4 unique segments (0 laser double-burns)
- PASSFlute & Kerf Tolerance Guard: T=3.00mm, K=0.120mm within structural limits
- PASSISO Layer Color Separation: CUT (Red), CREASE (Blue), SCORE (Emerald), DIMENSIONS isolated
- PASS1:1 Physical Unit Header: Explicit mm/in SVG viewBox + DXF $INSUNITS=4 + 50mm PDF bar
- PASSExact 2D Cut Bounding Parity: Cut Bounds 120×80mm === Blank Size
- PASS2D ↔ 3D Kinematic Model Sync: Archetype 'living_hinge' synced (2 3D component(s))
- PASSTrue Vector Sheet Nesting Sync: 1:1 vector paths mapped to multi-up sheet grid
A laser-cut Living Hinge (kerf-bending flexure lattice) transforms rigid 3mm plywood, MDF, or acrylic into a flexible sheet capable of bending smoothly around 90-degree or 180-degree curves without steam bending. Instead of bending wood fibers in compression, a living hinge works via micro-torsion of narrow alternating vertical bridges separated by interlocking laser slits. Our parametric engine computes the exact bend zone arc length from your target Bend Radius (input as Height H) and generates alternating longitudinal slits with tear-resistant bridge spacing.
Mathematical Blank & Tolerance Formulas
Computes the exact neutral-axis arc length required for a smooth 90-degree corner wrap of radius R_bend.
Limits torsion angle per individual wood bridge to < 8 degrees so the hinge bends repeatedly without snapping.
Step-by-Step Export & Assembly Guide
- 1 Enter total Panel Length (L), Panel Width (W, height of the hinge slits), and Target Bend Radius (in the Height H field, e.g., 35mm).
- 2 Inspect the centered living hinge lattice zone and the surrounding solid mounting wings.
- 3 Export as 1:1 .DXF or .SVG.
- 4 CRITICAL WOOD GRAIN RULE: Orient the plywood on your laser bed so the surface wood grain runs PARALLEL to the long living hinge slits—if cut perpendicular to the grain, the short fibers will snap when bent.
Material Thickness, Creasing Matrix & Laser Kerf Settings
| Material / Sheet Stock | Caliper Thickness (T) | Recommended Tooling / Laser Setup | Allowance / Kerf Spec | Primary Use Case |
|---|---|---|---|---|
| 3mm Baltic Birch Plywood (3-Ply) | 3.0 mm | CO2 or Diode Laser (Grain parallel to slits!) | Column Pitch: 2.0mm / Bridge: 4.0mm | Curved book-style boxes, lamp shades, rounded enclosure corners |
| 3mm MDF (Medium Density Fiberboard) | 3.0 mm | CO2 Laser | Column Pitch: 1.8mm / Bridge: 4.5mm | Tight radius bends (down to R = 20mm) because MDF has no directional grain |
Frequently Asked Questions — Living Hinge Generator
Why did my laser-cut living hinge snap when I tried to bend it?
95% of living hinge failures happen because the plywood grain was oriented perpendicular to the cut slits. Always align the wood grain parallel to the long hinge cuts so the continuous wood fibers twist in torsion rather than snapping across the grain.
What is the minimum bend radius for 3mm plywood?
For 3mm Baltic Birch plywood, a bend radius of R >= 25mm (giving a 90-degree bend zone width of ~42mm with 19 slit columns) bends comfortably dry. For tighter radii (15mm–22mm), lightly mist the back of the hinge with warm water or rubbing alcohol before bending.
Does this generator create single-line cuts for fast laser cutting?
Yes! Each living hinge slit is generated as a single vector line on the SCORE/CUT layer rather than a narrow double rectangle, cutting laser machine time in half and preventing excessive charring.
Can I use a living hinge on cast acrylic?
Thin extruded or cast acrylic (1.5mm to 2.0mm) and polypropylene can flex gently with wide living hinge patterns, but wood and MDF are far more durable for 90-degree cold bends.
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