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3d-printing
Mar 26, 2026
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Printing Carbon Fiber Filament on the Kobra 3
kobra3carbon fiberpla cfpetg cfhardened steel
PLA-CF and PETG-CF print stronger, stiffer, and lighter than standard materials — but they're abrasive and need specific handling.
Hardware Requirements
- Hardened steel nozzle required — CF chews through brass nozzles in hours
- The Kobra 3 stock nozzle is hardened steel — you're good
- Do NOT use a 0.2 mm nozzle with CF — minimum 0.4 mm
PLA-CF Settings
| Setting | Value |
|---|
| Nozzle temp | 220–230°C |
| Bed temp | 65°C |
| Speed | 60–80 mm/s |
| Fan | 80–100% |
| Retraction | 0.8 mm |
| Flow | 95–98% |
PETG-CF Settings
| Setting | Value |
|---|
| Nozzle temp | 240–250°C |
| Bed temp | 85°C |
| Speed | 50–70 mm/s |
| Fan | 20–30% |
| Retraction | 1.2 mm |
| Flow | 95% |
Key Differences from Standard Materials
- Layer adhesion is weaker — CF interrupts polymer chains. Use 4+ walls.
- Very low warping — fibers resist shrinkage
- Brittle in thin sections — design walls thicker than you would for PLA
- Excellent stiffness — great for structural brackets, tool holders, drone frames
- Matte finish — CF gives a distinctive matte black look
Common Issues
| Issue | Fix |
|---|
| Rough surface | Normal for CF — sand if needed |
| Layer delamination | Increase nozzle temp, reduce speed |
| Snapping mid-print | Too brittle — increase wall count |
| Nozzle wear (brass) | Switch to hardened steel immediately |
Not Suitable For
- Fine detail work — CF particles reduce resolution
- Anything requiring post-processing with acetone
- Multi-color with ACE Pro (abrasive wears hub)