Bottom line: rough carbon fibre prints come from the fibre content itself plus layer height, flow, temperature and nozzle wear. Fibre-filled materials will never look as smooth as unfilled filament, but the roughness can be reduced. Fix flow and wear first, then adjust layer height and outer wall speed.
Main causes
| Cause | Effect |
|---|---|
| Fibre content | Inherently matte, textured surface |
| Layer height too large | Visible ridges |
| Flow too high | Bumpy, blobby surface |
| Low temperature | Poor fusion, dull surface |
| Worn nozzle | Uneven line width |
Improvement steps
- Calibrate flow.
- Check nozzle wear and replace if needed.
- Reduce layer height.
- Raise temperature within the material window.
- Slow the outer wall.
Costly mistakes
- Expecting unfilled-filament smoothness.
- Increasing flow to fill gaps.
- Ignoring nozzle wear.
- Printing too cold.
- Judging under different lighting.
Buyer / engineer checklist
- Is flow calibrated?
- Is the nozzle in good condition?
- Is layer height suitable?
- Is temperature adequate?
- Is the surface requirement realistic?
Share the defect photo and settings and we can help improve the finish.Printing advice