3D Design: Modeling for Print Strength

FDM parts are 'anisotropic'—they are much weaker along the layer lines (Z-axis) than across them (X/Y).

1. Orientation is Everything

Design your parts so that the highest stresses are perpendicular to the layer lines. Never rely on layer adhesion for structural tension.

2. Use Fillets

Sharp corners are 'stress concentrators'. Add 2-3mm fillets to inside corners to distribute the load across more layers.

3. Avoid Large Overhangs

Overhangs require support, which ruins surface finish. Design with 45-degree chamfers to allow the printer to 'self-support'.

4. Hole Sizing

3D printed holes tend to shrink. Add 0.2mm to your diameter in CAD if you need a specific bolt to fit perfectly without drilling.