The Most Common 3D Printing Mistakes

Summary:

Even with quality filament, 3D printing requires calibration and good practices. In this FIL3D (TUCAB) guide you will find typical problems, with causes, quick fixes and prevention, as well as support tables and FAQ.

 Essential good practices (before printing)

• Leveling + Z offset impeccable (first layer test).

• Filament dry and well stored (hermetic box with silica/dehumidification).

• Profiles by material on the slicer (temperatures, fan, bed, retractions).

• Maintenance: clean nozzle/table, lubricated guides, tensioned belts, tight pulleys.

• Calibration: flow/extrusion, PID temperatures, short tests before parts long.

Errors and solutions

In each error: What it is · Causes · How to fix it now · Prevention

1) Overhang (excessive protrusions)

What it is: Sloped areas without support deform above ~45°.
Causes: Insufficient cooling; high temperature; thick layer; no supports.
Fix now: Enable supports; increase ventilation of the part; reduce temperature 5–10 °C; decrease speed; thinner layer.
Prevention: Orient the model; test limits with test pieces.

2) Clogged extruder/nozzle

What it is: Irregular or non-existent flow due to obstruction.
Causes: Residues, poor purging, wet/unclean filament, being “hot” without extruding.
Correct now: Needle/cleaning filament, cold pull, purge; if necessary, dismantle hotend.
Prevention: Purge during exchanges; do not keep the hot nozzle still; dry FIL3D filament.

Layer shift speed/acceleration, tension belts, tighten pulleys, activate Z-hop.
Prevention: Stable base, mechanical check.

Missing/skipping layers

What it is: Missing layers (gaps) due to extrusion/ irregular Z.
Causes: Layer height incompatible with nozzle, subextrusion, “stuck” Z guide.
Fix now: Adjust layer height (e.g.: nozzle 0.4 → ≤0.28–0.32 mm), temperature, lubricate Z, correct flow.
Prevention: Shaft maintenance; validated profiles.

Impression “in the air” / “noodles”

What it is: Initial adhesion failure; filament “nest” shape.
Causes: Wrong Z offset; poorly calibrated ABL sensor; knot/break in the filament.
Correct now: Level table, adjust Z offset, check sensor; remove node; purge and relaunch.
Prevention: Check-list before printing; observe the first layers.

 Loose superficial hairs

What it is: Fine hairs stuck together.
Causes: Dirt on the beak; poorly adjusted cooling/retraction.
Correct now: Clean nozzle; tweezers for removal; review cooling/shrinkage.
Prevention: Routine cleaning.

First layer without adhesion

What it is: Piece comes off at first.
Causes: Table misaligned; high beak; dirty surface; cold bed.
Correct now: Leveling, Z offset, adhesive (glue/lacquer/PEI), hot bed (material strip); denim/raft.
Prevention: First layer ritual.

Contraction in the first layers

What it is: Thermal gradient shrinkage (ABS/PA).
Causes: Bed/environment out of range; excessive ventilation.
Correct now: Correct bed, enclosure, minimum fan; improve adhesion.
Prevention: Materials suitable for the environment.

Walls do not touch

What it is: Cracks between perimeters.
Causes: Underextrusion; wrong diameter/flow; loose belts.
Correct now: Reduce speed or increase temperature; correct diameter; +5% flow; tension belts.
Prevention: Flow calibration.

Subextrusion

What it is: Lack of material (hollow walls/tops with holes).
Causes: Partially clogged nozzle; low temperature; roller getting stuck.
Correct now: +5–10 °C, -speed, confirm diameter/flow, clean nozzle.
Prevention: Filament dry; maintenance.

Spaced lines on the first layer

What it is: “Stripes” with spaces at the base.
Causes: High beak; little compression of the first extrusion.
Correct now: Decrease Z offset slightly; 1st layer thicker (0.28–0.3 mm with nozzle 0.4).
Prevention: 1st layer test.

Poor finish in suspended areas

What it is: Dropped wires in overhangs.
Causes: Inadequate supports/cooling.
Fix now: Supports optimized, more cooling, -temperature, -speed, thinner layer.
Prevention: Preview and profiles by material.

Ghosting/ringing

What it is: Waves after corners due to vibration.
Causes: High speed/acceleration; structure not very rigid.
Correct now: -speed/-acceleration, base rigid, belts/pulleys ok; if any, Input Shaping.
Prevention: Structural tightening and maintenance.

Stringing (wires between islands)

What it is: “Spider weaves” between separate parts.
Causes: Insufficient retraction; high temperature; travel slow; humidity.
Correct now: Retraction (direct 0.8–2 mm; Bowden 4–6 mm; 25–60 mm/s), -5–10 °C, travel 120–150 mm/s, dry filament; “Avoid crossing perimeters”.
Prevention: Correct storage.

Warping (corners to lift)

What it is: Arched base; raised corners.
Causes: Contraction when cooling; cold/draft environment.
Fix now: Warm bed, enclosure (ABS/PA), adhesive + denim/raft, minimum fan, stable location.
Prevention: Planning by material/part.

Bottom layers more wide (“elephant foot”)

What it is: Base widened by crushing/heat.
Causes: Low Z offset; very hot bed; late cooling.
Correct now: Increase offset Z cents; lower bed after 5–10 layers; turn on phased cooling.
Prevention: Chamfer in the model (if applicable).

Tops not closed (pillowing)

What it is: Holes/undulations in the ceiling.
Causes: Few top layers; weak cooling; infill sparse.
Fix now: ≥0.6–0.8 mm top, 100% fan on top (PLA), +infill density, -temperature in the last layers.
Prevention: Top thickness rules by layer height.

Filament breaks easily

What it is: Brittle filament (humidity/age).
Causes: Inadequate storage; UV; humidity.
Correct now: Dry filament; replace degraded rolls.
Prevention: Airtight bag + silica / dry boxes.

Lack of adhesion between layers/piece detaches

What it is: Detachment in layers or supports.
Causes: Low temperature; strong fan; insufficient supports.
Correct now: +temperature, -fan, supports correct; review orientation of the part.
Prevention: Profiles validated by material.

Slight ripples on surfaces

What it is: Discreet irregular texture.
Causes: Vibration; guides/bearings; speed.
Fix now: -speed, solid base, check bearings, tighten screws, lubricate.
Prevention: Scheduled maintenance.

Ambient temperature affecting printing

What is: Cold/hot environment/drafts generate failures.
Causes: Air currents; cold/hot room.
Fix now: Enclosure, move away from windows/AC; print at ~20–28 °C.
Prevention: Controlled location.

“Perfect” supports, invisible part

What it is: Model was below the virtual table.
Causes: Positioning/rotation in the slicer.
Fix now: “Place na base/Drop to bed”; confirm in the preview.
Prevention: Rotation/positioning with discretion.

Excessive piece “glued” to the table

What it is: Difficult to remove.
Causes: Bed too hot; excessive adhesive; low offset.
Fix now: Cool bed; use removable stickers; rise offset Z; lower bed at the end.
Prevention: Fine adjustment of the first layer.

Fragile/failed infill

What it is: Filling with holes or little resistance.
Causes: Low density; high speed; subextrusion.
Correct now: +density (15–25% functional parts), -speed of the infill, check flow/diameter, infill pattern that supports the top.
Prevention: Profiles by function.

Surface with bubbles/holes (pillowing)

What it is: Same as #17 (ceiling “sinking”).
Causes/Solutions: See #17.

Part warping during printing

What it is: Off-axis inclination.
Causes: Play in belts/pulleys; collisions.
Fix now: Tension belts, tighten pulleys, Z-hop/retractions to avoid touching.
Prevention: Mechanical inspection.

Wet filament — extrusion failures

What it is: Cracks, bubbles, matte/rough finish.
Causes: Moisture absorption.
Correct now: Dry filament (time/temperature depending on material); reprint.
Prevention: Storage sealed with silica.

Ghosting/ringing

What it is: Repeated shadows near corners/letters.
Causes: Vibrations; high acceleration.
Fix now: -speed/-acceleration/jerk, rigid base, tight frame, tensioned belts, Input Shaping (if applicable).
Prevention: Dynamic adjustment.

Fine details do not appear

What it is: Very fine letters/textures are lost.

Causes: Wide beak; line width high; large layer heights. Fix now: Nozzle 0.2–0.3 mm, line width smaller, 0.08–0.12 mm layer, activate Thin Walls/Detect Thin Walls, -speed. Prevention: Choose nozzle according to detail.

Useful tables: temperatures and adhesion by material 

Typical ranges (adjust according to printer and brand; use as a starting point).

FIL3D Material	Nozzle (°C)	Bed (°C)	Part fan	Membership notes
PLA	195–215	50–65	High after 1st layer	PEI/glass with glue; optional denim
PETG	225–245	70–85	Low–Medium	Avoid excessive cooling; strong adhesion to PEI (use separating glue)
ABS/ASA	235–255	95–110	Minimum	Enclosure recommended; avoid drafts
TPU (flexible)	205–225	40–60	Low	Low speeds; short retraction
PA (Nylon)	245–265	70–90	Minimum	Filament dry; enclosure help

Quick checklist (immediate diagnosis) 

• Does the part come off? → Level table · Lower offset Z · Adhesive · +Bed · Brim/Raft

• Are there wires (stringing)? → +Retraction · -Temperature · +Travel · Dry filament

• Corners lift (warping)? → +Bed · Enclosure · -Fan · Adhesive + Brim

• Holes at the top? → +Top layers · +Cooling on top · +Infill · -Final temperature

• Wavy surface (ghosting)? → -Speed/-Acceleration · Rigid base · Belts/pulleys

• Subextrusion? → +Temp · -Speed ​​· Clean nozzle · Correct flow/diameter

• Shifted layers? → Tension belts · Tighten pulleys · -Speed ​​· Z-hop

FAQ (frequently asked questions)

1) Why doesn't my first layer stick?

Almost always: leveling/Z offset. Clean the table, use adhesive, check the bed temperature and do a 1st layer test.

2) How do I eliminate stringing once and for all?

Retraction well tuned + temperature correct + travel fast + dry filament. And activate “avoid crossing perimeters”.

3) The ABS is always lifting in corners. Solution?

Enclosure, bed at 100–110°C, minimum fan, adhesive + denim/raft. Prevents drafts.

4) I have tops with holes. What's missing?

More top layers (≥0.6–0.8 mm), cooling on top, denser infill and controlling the temperature in the last layers.

5) I want more detail in the letters/engravings.

Use nozzle 0.2–0.3 mm, line width smaller, layer height 0.08–0.12 mm and -speed; activates “thin walls”.

Talk to us (TUCAB · FIL3D)

Do you need support with materials or parameters for your printer?
TUCAB manufactures FIL3D filaments in Portugal with strict diameter control and moisture, for consistent results.

Commercial contact/technical support: tucab.pt

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