ghbalf/freecad-ai/lattice

Lattice / Infill Pattern

Generate a 3D lattice or infill pattern inside a bounding region. Useful for lightweight structural parts.

Pattern types

• Grid: rectangular grid of holes or beams
• Honeycomb: hexagonal pattern (strongest weight-to-strength ratio)
• Diagonal: 45-degree crosshatch
• Gyroid (advanced): triply periodic minimal surface

Parameters to ask (if not provided)

• Pattern type: grid / honeycomb / diagonal
• Region: existing object to fill, or bounding box dimensions
• Cell size: distance between pattern centers (default 10mm)
• Wall thickness: thickness of lattice walls/beams (default 1.5mm)
• Height/depth: extrusion height of the pattern

Construction approach

Grid pattern

1. Create a sketch with a rectangular array of circles or squares
2. Use spacing = cell_size, hole diameter = cell_size - wall_thickness
3. Pad to height, then boolean-intersect with the bounding shape

Honeycomb

1. Create hexagonal cells: 6 line segments per cell
2. Hex radius = cell_size / 2
3. Offset rows by cell_size 0.75 horizontally and cell_size sqrt(3)/2 vertically
4. Pad and intersect with bounding shape

Diagonal crosshatch

1. Create parallel lines at 45 degrees, spaced by cell_size
2. Create second set at -45 degrees
3. Lines have width = wall_thickness
4. Pad and intersect

Important

• Always create the lattice larger than the target region, then use boolean intersection to trim
• Label clearly: "Lattice Grid 10mm" etc.
• For 3D printing, ensure wall_thickness >= 2x nozzle diameter (typically >= 0.8mm)
• After construction, hide all sketches for a clean viewport:

for obj in App.ActiveDocument.Objects:
    if obj.TypeId == "Sketcher::SketchObject":
        obj.Visibility = False