15 Common 3D Printing Errors & Fixes (FDM + Resin Guide 2026)

You bought a 3D printer. The first "Benchy" boat came out perfect. Then you tried a real part and everything went sideways — warping, stringing, layer shifts, parts not sticking. The questions pile up: "Is the printer broken? Are my slicer settings wrong? Is the model itself faulty?"

This guide covers the 15 most common print errors you'll face on FDM and resin printers — each with cause + fix. Includes specific tips for Bambu Lab, Prusa, Creality, Anycubic machines.

Quick Diagnosis Table

By symptom:

Symptom	Likely Cause	Section
Edges curling up (warp)	Bed adhesion, heat	#1
Stringy fibers between parts	Retraction settings	#2
Won't stick to bed	First layer calibration	#3
Bottom is bulged out (elephant foot)	First layer crushed	#4
Layers shifted sideways	Belt or acceleration	#5
Holes on top surface (pillowing)	Low infill	#6
Print collapsed mid-way	Filament or extruder	#7
Brown/purple blobs (zits)	No Z-hop	#8
Vertical lines on side	Z-wobble	#9
Ringing after corners (ghosting)	Vibration	#10
Resin sticking to FEP tank	Worn FEP film	#11
Resin layers separating	Exposure time	#12
Resin model dropped from vacuum	No drain holes	#13
Resin print soft / brittle	Cure time	#14
Support marks too rough	Support settings	#15

FDM PRINTER ISSUES

1. Warping (Edges curling up)

Symptom: Corners or long edges of the print lift off the build plate, curling upward.

Causes:

• Material shrinks as it cools (especially ABS, Nylon)
• Bed temperature too low
• Weak bed adhesion
• Rapid cooling (fan too high)
• Loose first layer

Fixes:

1. Increase heated bed temperature:
   • PLA: 60°C
   • PETG: 70-80°C
   • ABS: 100°C (enclosed chamber required)
2. Add a brim (5-8mm border)
3. Use a raft (for ABS, Nylon)
4. Enclosed environment — mandatory for ABS/Nylon
5. Reduce fan speed — first 10 layers 0%, then 50%
6. Glue stick or DimaFix — extra adhesion

Bambu Lab: With AMS off, disable chamber fan. Prusa: Use the Textured PEI sheet.

2. Stringing (Fine threads)

Symptom: Thin strings appear between two objects, like spider webs.

Causes:

• Insufficient retraction
• Nozzle too hot
• Slow travel speed
• Wet filament

Fixes:

1. Increase retraction distance:
   • Bowden (Creality): 5-6mm
   • Direct drive (Bambu, Prusa): 0.5-1mm
2. Retraction speed: 40-60 mm/s
3. Lower nozzle temperature by 5°C
4. Travel speed: 150+ mm/s
5. Dry the filament — 4-6 hours at 50°C

Bambu Lab: Run Flow Dynamics calibration (per-color when using AMS). Prusa: Keep Linear Advance enabled.

3. First Layer Won't Stick

Symptom: First layer doesn't bond to the bed; extruder makes a clicking sound.

Causes:

• Nozzle too high
• Bed not clean (oils, dust)
• Bed level off
• First layer too fast

Fixes:

1. Bed leveling — auto or manual, 4 corners + center
2. First layer height: 0.3mm (instead of standard 0.2mm — wider first layer)
3. First layer speed: 20-25 mm/s (slow)
4. Clean: Wipe bed with IPA (isopropyl alcohol)
5. Adjust Z offset: paper test — A4 paper should drag slightly under nozzle
6. Brim or raft as last resort

Bambu Lab: Run auto bed leveling before every print. Creality K1: Manually adjust first layer offset. Anycubic: Spray adhesive (3DLAC) gives good results.

4. Elephant Foot

Symptom: Bottom of the print is wider than the top — looks slightly squished.

Causes:

• Bed temperature too high
• First layer over-compressed (nozzle too close)
• Insufficient cooling at start

Fixes:

1. Raise first layer Z-offset: +0.05mm
2. Lower bed temperature by 5°C
3. First layer fan: 10-20% (normally 0%)
4. Add chamfer/fillet to model bottom — software-side fix
5. Slicer "Elephant foot compensation": Cura 0.1-0.2mm, PrusaSlicer "Line width compensation"

5. Layer Shift

Symptom: After a certain point, upper layers are shifted sideways — staircase look.

Causes:

• Loose belt (X or Y)
• Acceleration too high
• Motor skipping
• Print collision

Fixes:

1. Check belt tension — should give a taut "guitar string" sound
2. Reduce acceleration: FDM 1000-2000 mm/s²
3. Reduce speed: 100-150 mm/s
4. Check motor current (advanced)
5. Clean gantry rails — dust → resistance

Bambu Lab: Calibrate input shaping (X1 Carbon does it automatically). Creality Ender 3: Y-axis belt loosens often, weekly check.

6. Pillowing (Top surface holes/dents)

Symptom: Top layer is bumpy with holes, like pillows.

Causes:

• Low infill density
• Too few top layers
• Insufficient cooling

Fixes:

1. Top layers: 4-5 (minimum 4 for 0.2mm layer height)
2. Infill: 15-20% minimum
3. Cooling fan 100% on top layers
4. Infill pattern: Grid or gyroid (supports the top)
5. Enable ironing (smooths the top surface)

7. Mid-print Collapse

Symptom: Print stops at 50% or extruder starts clicking.

Causes:

• Filament ran out or knotted
• Nozzle clogged
• Extruder motor overheated
• PTFE tube blockage

Fixes:

1. Check filament for knots — wind it neatly before print
2. Nozzle unclog: cold pull technique
3. Replace nozzle — every 6 months or after abrasive (CF, GF) filament
4. Check PTFE tube — inspect inside, replace if needed
5. Adjust extruder tension — pulley pressure correct?

Bambu Lab: AMS has auto unclog routine; X1 has a "Wipe" button.

8. Blobs / Zits

Symptom: Small bumps on the surface, at every nozzle start/stop.

Causes:

• No Z-hop (nozzle stays down during retraction)
• No coasting
• No wipe

Fixes:

1. Enable Z-hop: 0.2mm
2. Enable coasting: 0.2mm (lets nozzle finish before retract)
3. Seam position: "Random" or "Aligned" (on hidden surface)
4. Clean nozzle: brass brush on cold nozzle exterior

9. Z-Wobble (Z-axis wave)

Symptom: Regular wavy lines on side surface, 1-2mm spacing.

Causes:

• Bent Z lead screw
• Loose Z nut
• Bad coupler

Fixes:

1. Align Z screw — common on Creality Ender
2. Replace Z coupler — oblique coupler is better
3. Lubricate lead screw — lithium grease
4. Mag rail upgrade (Prusa MK4 already has it)

10. Ghosting / Ringing (Echo after corners)

Symptom: Wavy "echo" pattern just after sharp corners.

Causes:

• Vibration at high print speed
• Frame not rigid
• Loose belt

Fixes:

1. Input shaping / resonance compensation:
   • Bambu X1/P1: auto
   • Prusa MK4: auto
   • Klipper (Ender 3 upgrade): SHAPER_CALIBRATE
2. Reduce print speed: 80-100 mm/s (unless you're chasing speed)
3. Place printer on rigid surface — vibration-dampening mat
4. Reduce acceleration: 2000 → 1500 mm/s²

RESIN PRINTER ISSUES

11. FEP Film Sticking

Symptom: Print sticks to the FEP instead of the build plate.

Causes:

• Worn FEP film
• Over-exposure (over-cure)
• Unsupported overhangs

Fixes:

1. Replace FEP film — every 50-100 prints
2. Run exposure test — Cones of Calibration model
3. Add supports — automatic auto-supports may not be enough
4. Lower lift speed (peel speed)
5. Model orientation — tilt 30-45° instead of flat

Anycubic Photon: In Chitubox set "Transition Layers: 5" — first layer holds better.

12. Resin Delamination (Layers separating)

Symptom: Print tears between layers, layer lines visible.

Causes:

• Insufficient exposure time
• Warped FEP film
• Old or poorly mixed resin
• Low ambient temperature (e.g., printing in a cold garage)

Fixes:

1. Increase exposure time — run a test matrix (+20%)
2. Mix the resin — shake the bottle 30 seconds before use
3. Resin temperature: 25-30°C optimal — use a tank heater in winter
4. Check FEP — press with finger; rebound should be quick
5. Bottom layer count: 4-6 (not too few, not too many)

13. Vacuum Failure

Symptom: Large objects (like Warhammer mini bodies) drop during print.

Cause: Negative pressure builds up in hollow interiors; lift force isn't enough.

Fixes:

1. Hollow out — use Chitubox "Hollow" button
2. Add drain holes — 2-3 holes, 3-4mm diameter
3. Orientation — make sure holes face down
4. Add internal supports in the hollow section

14. Soft / Brittle Print

Symptom: Print cracks when removed from plate, or feels rubbery.

Causes:

• Insufficient post-cure
• Poor wash (IPA residue)
• Old resin

Fixes:

1. Wash time: 5-10 min in 95%+ IPA (don't shorten)
2. Post-cure: 5-15 min UV lamp (depends on size)
3. Water bath cure — distributes UV evenly
4. Fresh resin — replace if opened > 6 months
5. Resin brand test: Use ABS-like or Tough resin for non-brittle parts

15. Bad Support Marks

Symptom: Holes/marks on model after support removal.

Causes:

• Support tip too thick
• Contact tip too wide
• Wrong removal timing (too hard or too soft)

Fixes:

1. Tip diameter: 0.3-0.4mm (small)
2. Z-distance: 0.3mm (don't quite touch)
3. Light supports: small contact based on object group
4. Removal timing: after IPA bath, supports are soft — break then
5. Re-wash + post-cure afterwards

Printer-Specific Settings

Bambu Lab X1 Carbon / P1S / A1

• Auto bed leveling: Keep on every print
• Input shaping: Auto-calibrate
• Flow dynamics: Calibrate once per filament
• With AMS: retraction differs; PLA-PETG swaps need a purge tower
• Chamber fan: 20-40% for PLA, 0% for ABS

Prusa MK4 / XL / Mini+

• Input shaping: auto (manual on Mini)
• Linear Advance: K=0.04 PLA, K=0.06 PETG, K=0.10 ABS
• Satin PEI: perfect for PETG and PLA
• Smooth PEI: PLA, easy removal
• Textured PEI: ABS, strong adhesion

Creality Ender 3 / K1 / K2

• Belt tension: weekly check (especially Ender series)
• Z-axis lubrication: monthly
• Klipper upgrade recommended — 2x performance gain
• PEI sheet upgrade — default surface is weak

Anycubic Photon Mono / M5s / Kobra

• Kobra (FDM): auto bed leveling 49 points, slow
• Photon (SLA): keep LCD clean, wipe with IPA
• Resin tank level: ¾ full, don't overfill
• Exposure tables — Chitubox default profile works well with Anycubic resin

General Tips

"5-minute pre-print check"

1. Is the nozzle clean?
2. Is the bed clean (wiped with IPA)?
3. No knots in the filament?
4. Slicer settings correct (material + printer match)?
5. Visually verify first layer (first 2 minutes)

Filament Storage

• PLA: plastic bag + silica gel — open air 3 months
• PETG: moisture absorber — 6 months
• Nylon: mandatory drying, 4 hours at 60°C before each use
• ABS: less critical for moisture but keep sealed

Nozzle Maintenance

• 0.4mm brass: PLA, PETG, ABS (6-month life)
• Hardened steel: required for carbon fiber, glass-filled
• Ruby tip: abrasive filament, long life but expensive

Post-processing

• FDM:
  • Sanding (100 → 400 → 1000 grit)
  • Acetone vapor smoothing (ABS only)
  • Primer + spray paint
• Resin:
  • IPA wash (5-10 min)
  • UV cure (5-15 min)
  • Sand support marks
  • Airbrush paint final

FAQ

Which printer should I buy?

• Low budget, beginner: Creality Ender 3 V3 KE ($250) or Bambu A1 Mini ($300)
• Mid-range, reliable: Bambu P1S ($650) or Prusa MK4 ($800)
• Pro: Bambu X1 Carbon ($1300) or Prusa XL
• Resin: Anycubic Photon M5s ($400) or Elegoo Saturn 3 ($500)

Is resin toxic?

Yes. Always:

• Nitrile gloves
• Ventilation (garage/balcony)
• Eye protection
• No skin contact before post-wash

Stable once UV-cured.

Which filament for the first month?

PLA — most forgiving, odorless, low temperature. ~$20-25/kg.

Is Bambu Lab AMS really worth it?

Yes. A revolution for multi-color printing. Even for single-color use, AMS Lite (cheaper version) is valuable for stock management.

How to shorten print time?

1. Increase layer height: 0.3mm (rough), 0.28mm (reasonable)
2. Speed: Bambu does 500 mm/s — watch for ghosting
3. Reduce infill: 10% is usually enough
4. Reduce walls: 2-3 if you don't need strength

Closing

3D printing is as much science as art. Every error teaches you something. The 15 issues in this guide cover all beginner-to-intermediate problems — bookmark this page and Ctrl+F when stuck.

In Geomeris, when generating AI models, keep flatten bottom + mesh validation enabled — manifold mesh is critical for printing success.

👉 Generate a 3D model in Geomeris (free plan)

Related guides:

• STL Converter: 3D Printing Guide
• How to Create 3D Models from Photos
• 3D File Formats: GLB, STL, OBJ, FBX