3D print errors: The 10 most common problems and their solutions

In short — the 10 most common 3D printing errors:

• The 3 most common errors are poor bed adhesion, warping and stringing — all three can be fixed without buying a new printer.
• Most errors are caused by wrong temperature, wrong speed or missing calibration — not bad equipment.
• Material choice matters more than people think: PLA is forgiving, PETG needs tuning, ABS and PA6-CF need a controlled environment.
• Getting errors that won't go away? We'll print it for you — contact us and skip the tuning work.

Table of contents

1. Poor bed adhesion
2. Warping
3. Stringing
4. Under- and over-extrusion
5. Layer delamination
6. Elephant's foot
7. Z-wobble and layer shifting
8. Support failures and overhangs
9. Clogged nozzle
10. Wrong slicer settings
11. FAQ

Symptom: The first layer lifts off the bed mid-print, or the print curls up at the corners. This is by far the most common error in 3D printing, regardless of printer or material.

Cause: The bed isn't clean, the temperature is wrong, or the first layer is printed too fast or too high above the bed. Fingerprints and dust are underrated culprits — skin oils make it impossible for the plastic to adhere properly.

Fix: Clean the bed with isopropyl alcohol before every print. Use the correct bed temperature (60°C for PLA, 70-80°C for PETG, 100-110°C for ABS). Slow down the first layer to 20 mm/s, and calibrate your Z-offset so the nozzle almost squeezes the plastic into the bed. The first layer should look slightly "squished," not round.

Symptom: Corners and edges lift off the bed during the print, and the part ends up warped or cracked.

Cause: 3D printing warping happens when the plastic cools unevenly — the outer layers contract before the inside does, and the stress pulls the part up off the bed. Worst in ABS, ASA and PA6-CF, milder in PETG and almost absent in PLA.

Fix: Use a heated bed, add a brim or raft to increase the contact area, and print in an enclosed chamber if possible. For ABS and PA6-CF, an enclosure is nearly a requirement. Avoid drafts in the workshop — an open door mid-print can cause warping on large parts by itself.

Symptom: Thin plastic strands between parts of the print, like cobwebs between towers or across open geometries.

Cause: 3D printing stringing happens when the nozzle leaks plastic during "travel" moves across the print without actively extruding. Usually caused by the wrong retraction distance, too high a temperature, or damp filament. PETG is particularly sensitive.

Fix: Increase retraction distance (typically 4-6 mm for direct drive, 6-8 mm for Bowden), lower the print temperature by 5-10°C, and dry the filament in a filament dryer if it's been sitting out for a while. Damp PETG can produce significantly more stringing than fresh filament.

Symptom: Under-extrusion shows up as gaps between layers, missing layers or weak prints. Over-extrusion shows up as lumpy surfaces, blobs and imprecise details.

Cause: Wrong flow rate, wrong filament diameter in the slicer, a blocked nozzle, or a mismatched combination of temperature and speed. Worn extruder gears are also a classic culprit.

Fix: Calibrate the extruder e-steps against a known reference length (mark 100 mm of filament and extrude 100 mm — measure what was actually used), measure your actual filament diameter with calipers, and run a flow-rate calibration. Good starting point: 100% flow ± 5%.

Symptom: The layers split apart — either while the part is printing or when you pick it up and apply mechanical load.

Cause: Print temperature too low, cooling too fast, or print speed too high. The layers simply don't get time to fuse together properly.

Fix: Raise the temperature by 5-10°C, turn off or reduce the part-cooling fan for materials like ABS and PA6-CF, and lower the print speed. Layer delamination in PA6-CF almost always means the nozzle is too cold or the fan speed is too high — the material needs heat and calm.

Symptom: The bottom of the print is wider than the rest — the part "spreads" on the first few layers, and the dimensions at the bottom don't match the CAD file.

Cause: The bed is too hot, or the first layer is pressed too hard against the bed. The plastic flows sideways instead of staying where it should.

Fix: Lower the bed temperature by 5°C, calibrate the Z-offset so the first layer is precise (not squished), and enable "first layer compensation" in your slicer if available. On small precision parts, a cool glass plate can make the difference.

Symptom: Side walls have waves, ribs, or offset layers that suddenly shift horizontally.

Cause: A bent Z leadscrew, loose belt tensioners, or mechanical vibration from the printer sitting on an unstable table. A single loose eccentric nut on the Y-axis can cause visible layer shifts all on its own.

Fix: Check the leadscrew for bending, tighten the belts (but not too hard — they should be as taut as a guitar string, no more), and place the printer on a stable, vibration-dampened surface. A small foam pad can solve more than people expect.

Symptom: Overhanging geometry "droops" or collapses, and supports are either impossible to remove or leave ugly marks on the surface.

Cause: Support density too aggressive, wrong support distance, or geometry that exceeds a 45° overhang without support.

Fix: Use tree supports where possible, set support distance to 0.2-0.3 mm, and consider rotating the part to minimize overhangs. On SLA, supports are a craft of their own — read our SLA 3D printing guide for details.

Symptom: The print stops extruding, or the filament "skips" back in the extruder with a characteristic clicking sound.

Cause: Burnt plastic in the nozzle, damp filament forming steam, or the wrong temperature for the material. A worn brass nozzle is a common cause with abrasive materials.

Fix: Run a cold pull (the heat-and-yank method), or replace the nozzle if it's old. If you're printing abrasive filament like PA6-CF or PETG-CF, use hardened steel — a brass nozzle can be worn out after just 50 hours with a carbon-fiber composite.

Tired of tuning?
If you've spent hours chasing errors, it's often faster and cheaper to have us print the part for you. Send the file and get a quote — typically the same day.

Symptom: The print looks fine in preview but fails in practice — wrong size, missing detail, or print time that's 3x what was expected.

Cause: The slicer's default profile doesn't match the actual printer, material profiles aren't up to date, or the correct nozzle size wasn't reselected after a swap.

Fix: Use the manufacturer's official profile as a starting point, and only adjust what you understand. Most beginner 3D printing errors come from changing 5 settings at once and not knowing which one made the print better or worse. Read more about FFF/FDM technology on Wikipedia if you want to understand what the settings actually do.

From experience
A customer sent us a PETG part with heavy stringing after spending a whole weekend adjusting temperature. We asked how long the filament had been sitting open. The answer was "since January." We dried a spool in the filament dryer for 6 hours, ran the same print, and the stringing was gone. That's the kind of error I see every month — it's not the printer, it's the filament that's absorbed moisture. The single fix that's saved me the most hours over the years: make one change at a time, and print a test cube afterward.

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