Printing Functional Parts — Infill Patterns and Wall Count Guide
fdminfillwall countfunctional partsstrength
Not all prints need to be the same. A display model needs different settings than a machine bracket. Here's how to choose infill and walls for functional parts.
Wall Count (Perimeters) — Most Important
Walls contribute more to part strength than infill in most cases.
| Use Case | Walls | Notes |
|---|---|---|
| Display/decorative | 2–3 | Minimum viable |
| Light functional | 3–4 | Clips, covers, mounts |
| Medium stress | 4–5 | Brackets, enclosures |
| High stress | 6–8 | Structural, mechanical |
| Near-solid (maximum) | 10+ | Tool components, gears |
Rule: If you're not sure, add a wall. Each wall = 0.4 mm (at 0.4 mm nozzle) × your print height in strength.
Infill Percentage
| % | Use For |
|---|---|
| 5–10% | Decorative, display, large hollow parts |
| 15–20% | Standard parts, light loads |
| 25–40% | Functional, impact-bearing parts |
| 50–80% | High stress components |
| 100% | Maximum strength (rarely needed — walls are more efficient) |
Infill Pattern Comparison
| Pattern | Strength | Speed | Best For |
|---|---|---|---|
| Gyroid | Excellent (isotropic) | Medium | Functional parts generally |
| Cubic | Good | Fast | General purpose |
| Grid | OK | Fast | Decorative, light use |
| Honeycomb | Good | Medium | Even load distribution |
| Lines/Rectilinear | Directional | Fastest | Flat surfaces |
| Lightning | None | Fastest | Top surface support only |
Recommendation: Gyroid for anything that needs to be strong. It's the only pattern that's equally strong in all directions.
Top/Bottom Layers
| Layer Count | Use Case |
|---|---|
| 3 | Minimum — often prints through on large flat surfaces |
| 4–5 | Standard recommendation |
| 6–8 | Watertight parts, smooth top surfaces |
Combined Recommendation for Strong Parts
- 5 walls
- 4 top/bottom layers
- 25% gyroid infill
- Slow down outer wall 20% below infill speed
This combination gives excellent results for mechanical parts without excessive print time.