Common 3D Printing Mistakes & How to Fix Them
Avoid Wasted Filament and Failed Prints with These Proven Troubleshooting Tips
Whether you’re a beginner or an enthusiast, 3D printing comes with a learning curve. Print failures are common, but most issues can be avoided with proper setup and awareness. This guide highlights the most frequent mistakes users make during 3D printing and how to fix them step by step. These solutions will help improve your print quality, reduce waste, and ensure your machine performs at its best.
1. Poor Bed Adhesion
Why It Happens
One of the most frustrating problems is when the first layer doesn’t stick to the print bed, leading to shifting or complete failure. This is often caused by an unlevel bed, dirty surface, or incorrect nozzle distance from the bed.
How to Fix It
- Always level the bed before starting a print — manually or via auto bed levelling.
- Clean the print surface with isopropyl alcohol to remove oils or dust.
- Adjust the nozzle height using a paper test or Z-offset to ensure it’s not too far above the bed.
- Use adhesives like glue stick, painter’s tape, or PEI sheets for better grip.
Real Example:
A TrinityLayers user printing a phone stand on a glass bed solved detachment issues by simply lowering the nozzle 0.1mm and wiping the bed with IPA.
→ Shop Bed Adhesion Tools and Surfaces
2. Stringing and Oozing Between Moves
Why It Happens
When the nozzle moves between print areas without proper retraction, it may ooze filament and leave unwanted strings behind. High temperatures and wet filament increase this problem.
How to Fix It
- Enable retraction in your slicer and fine-tune distance/speed.
- Lower the printing temperature in 5°C increments.
- Dry your filament in a filament dryer box or an airtight container.
Real Example:
A designer printing detailed miniatures reduced stringing by adjusting retraction and switching to a low-moisture PLA brand.
3. Warping and Curling Edges
Why It Happens
Warping is when the edges of a print lift and deform, especially during larger prints or with materials like ABS and Nylon. It happens due to uneven cooling and thermal contraction.
How to Fix It
- Use a heated bed (60–110°C, depending on material).
- Apply a brim or raft in your slicer to anchor the print.
- Use an enclosure to retain ambient temperature.
Real Example:
An ABS enclosure print that warped repeatedly was fixed by switching to an enclosed printer and increasing bed temperature to 100°C.
→ Shop Affordable Enclosed Printers
4. Under-Extrusion
Why It Happens
Under-extrusion results in thin layers, gaps in walls, or missing sections. It’s commonly due to clogged nozzles, low flow rate, or feeding problems.
How to Fix It
- Inspect and clean the nozzle regularly.
- Check for tight filament spools or worn-out extruder gears.
- Slightly increase the flow rate (extrusion multiplier) in the slicer.
- Ensure your filament diameter is set correctly in the slicer.
Real Example:
A TrinityLayers print partner resolved wall gaps in PLA prints by increasing flow rate from 100% to 105% and replacing a partially clogged 0.4mm nozzle.
→ Buy Nozzles, Extruders & Tools
5. Over-Extrusion
Why It Happens
Too much filament being pushed out leads to blobs, stringing, and rough surface quality.
How to Fix It
- Decrease the flow rate in the slicer to around 95–98%.
- Calibrate your extruder steps/mm using a 100mm extrusion test.
- Verify that the filament diameter matches the slicer input.
Real Example:
A beginner using 1.75mm PLA but the slicer set to 2.85mm saw massive over-extrusion. Changing the diameter fixed the issue instantly.
6. Layer Shifting
Why It Happens
Layer shifting leads to misaligned or slanted prints. Common reasons include loose belts, motor skips, or mechanical obstructions.
How to Fix It
- Tighten the X and Y axis belts evenly.
- Lubricate rails and pulleys with machine grease.
- Ensure the print head moves freely with no friction.
- Lower print speeds if needed.
Real Example:
A customer printing game controller shells fixed repeated X-axis shifting by tightening the belt and reducing print speed from 70mm/s to 50mm/s.
→ Buy Maintenance Kits & Belt Tools
7. Clogged Nozzle
Why It Happens
A partially or fully clogged nozzle results in missing layers or even a complete extrusion failure. This is usually due to burnt filament, dust, or low-quality materials.
How to Fix It
- Perform a cold pull using nylon or cleaning filament.
- Heat the nozzle to 220–240°C and manually extrude to dislodge debris.
- Use brass brushes and needle cleaning tools regularly.
Real Example:
An enthusiast using cheap PETG fixed clogs by upgrading to a cleaner filament and cold-pulling with cleaning filament weekly.
→ Buy Nozzle Cleaning Kits
8. Inconsistent Layer Lines
Why It Happens
Layer inconsistencies cause a rough or wavy surface and often result from vibration, loose hardware, or Z-wobble.
How to Fix It
- Tighten all screws and rods before long prints.
- Add rubber feet to stabilize your printer.
- Enable Z-hop and slower layer heights for high-detail parts.
Real Example:
A user building architectural miniatures fixed print waves by tightening Z-axis rods and placing the printer on a foam pad.
→ Get Vibration Dampeners & Z-Support Kits
9. Incorrect Supports
Why It Happens
Support structures are crucial for overhangs, but if they’re poorly placed or too dense, they can ruin the surface or be hard to remove.
How to Fix It
- Use tree supports for complex prints to minimize marks.
- Adjust support overhang angle to reduce unnecessary supports.
- Test placement in preview mode before slicing.
Real Example:
A customer printing cosplay armor parts optimized support settings and reduced post-processing time by 60%.
→ Try Our Free 3D Design Support Service
10. Using Wet or Expired Filament
Why It Happens
Moisture in the filament causes popping sounds, stringing, and weak prints. Even unused filament can absorb moisture over time.
How to Fix It
- Store filament in dry boxes or vacuum bags with silica gel.
- Use a filament dryer before critical prints.
- Avoid buying extremely old or unpackaged filament.
Real Example:
A prototype order failed twice due to brittle, old filament. Replacing it with a dry, fresh PLA reel produced flawless output.
→ Shop Verified & Fresh Filament Only
Final Thoughts
Mastering 3D printing means mastering the details. While the technology is revolutionary, small oversights can cause major failures. By understanding these common mistakes and applying the fixes we’ve outlined, you’ll save time, money, and filament. Whether you’re prototyping, designing, or printing final products, consistency comes with calibration and care.
Need help calibrating your printer or choosing the right tools? TrinityLayers is here to guide and supply you.