3D Printing Troubleshooting
A quick-reference guide for diagnosing and fixing the most common 3D printing problems. Find your symptom in the table below, apply the quick fix, and follow the linked guide for a full solution.
Quick diagnosis table
| Problem | What you see | Quick fix | Full guide |
|---|---|---|---|
| Stringing / hairing | Thin plastic threads between separate parts of the print | Reduce nozzle temp by 5°C. Enable combing mode. Increase travel speed. | Full stringing fix guide → |
| Warping / corner lifting | Corners or edges of the print lifting off the bed during or after printing | Increase bed temp. Add a brim (3–5 mm). Use enclosure for ABS/ASA. No cooling fan on first layers. | Full warping fix guide → |
| First layer not sticking | Print detaches from bed during first layers, or lines don't bond to the surface | Clean bed with IPA. Lower Z-offset by 0.05 mm. Verify bed temperature. Slow first layer to 25 mm/s. | First layer troubleshooting guide → |
| Under-extrusion | Gaps in walls, weak infill, rough surface texture, missing sections of layers | Increase nozzle temp by 5°C. Check for partial clog (cold pull). Calibrate flow rate. Check PTFE tube condition. | Calibration guide (flow rate) → |
| Over-extrusion | Walls wider than expected, blobs on surface, rough finish, dimensions too large | Reduce flow rate by 5% at a time. Check e-steps calibration. | Calibration guide (e-steps + flow) → |
| Clogged nozzle | No extrusion, clicking extruder, partial extrusion, filament grinding | Cold pull: heat to printing temp, cool to 90°C, pull fast. Repeat 3–5 times. If blocked: atomic pull at 80–85°C. | — |
| Layer separation / delamination | Layers splitting apart, weak Z-axis strength, visible gaps between layers | Increase nozzle temp by 5°C. Reduce print speed. Reduce cooling fan. Check for drafts (ABS/ASA). | — |
| Elephant foot | First layer wider than the rest of the print, flared base | Raise Z-offset by 0.025–0.05 mm. Reduce first-layer flow rate to 100%. Reduce bed temp by 5°C. | First layer guide → |
| Ghosting / ringing | Wavy ripple pattern on walls near sharp corners | Reduce print speed (outer wall to 40–50 mm/s). Tighten belts. Enable input shaper if available. | Speed settings guide → |
| Supports hard to remove | Supports tear the part surface, leave marks, or won't break free | Increase Z-distance to 0.25–0.3 mm. Enable support interface layers. For PETG: use textured PEI or glue stick. | Supports guide → |
| Wet filament symptoms | Popping/crackling sounds, bubbles on surface, rough texture, excessive stringing | Dry filament: PLA/PETG at 65°C for 4–6 hours. Nylon at 70°C for 8–12 hours. Store in sealed bags with desiccant. | — |
| Nozzle hitting the print | Scraping sound, knocked layers, failed prints mid-way through | Check Z-seam alignment. Reduce over-extrusion (flow rate). Increase retraction. Reduce print speed. | Retraction settings guide → |
How to diagnose a 3D printing problem
Start with the first layer. If the first layer is correct — flat, fully adhered, no gaps — most problems are slicer settings. If the first layer is wrong, fix it before diagnosing anything else.
- Symptoms appear on the first layer only
- Z-offset, bed temperature, or bed surface problem. See the first layer guide and the bed adhesion guide.
- Symptoms get worse as the print progresses
- Usually heat creep, partial clog, or wet filament. The nozzle starts clear but gradually clogs. Try a cold pull and dry the filament.
- Symptoms appear only at certain points in the print
- Often a slicer issue — retraction at certain move types, speed changes, or layer transitions. Check retraction settings and combing mode.
- Symptoms consistent across the whole print
- Temperature, flow rate, or e-steps calibration. These affect every layer equally. Recalibrate flow rate and check nozzle temperature with a separate thermometer.
- Print fails suddenly mid-print
- Filament runout, partial clog suddenly becoming a full clog, bed adhesion failure, or power issue. Check the extruder first — if it's clicking, the nozzle is blocked.
Wet filament: often the hidden cause
Moisture in filament causes or worsens stringing, rough surfaces, weak layer bonding, popping sounds, and poor dimensional accuracy. It is often misdiagnosed as a temperature or retraction problem. If you have adjusted settings repeatedly without improvement, dry the filament first.
Dry times and temperatures: PLA — 65°C, 4–6 hours. PLA+ — 65°C, 4–6 hours. PETG — 65°C, 4–6 hours. ABS — 80°C, 4 hours. Nylon — 70–80°C, 8–12 hours. TPU — 60–65°C, 4–6 hours. Use a food dehydrator, Polymaker PolyDryer, or oven at the lowest setting (verify temperature with a separate thermometer — most ovens run hot).