When printing, unexpected challenges may arise that will need to be resolved in order to complete a successful print.  Often times, the appropriate response to a printing issue is not immediately apparent.  This guide outlines some of the most common issues faced by 3D printing practitioners and highlights steps that may be taken to resolve those issues.

Not extruding at the start of the print  Print not sticking to bed  Jammed nozzle/clogged extruder  Pillowing, e.g. incomplete top layer fills, top layer holes/gaps 
Smashed first layer, aka elephant’s foot; bulging first layer  Warping or corner lifting  Layer separation or warping within the part  Shifted layers or leaning prints 
Stringing / hairy prints  Overhangs or sagging sections in the print  Support material difficult to remove  Under extrusion, e.g. not extruding enough plastic or insufficient material 
Grinding filament and/or extruder motor skipping  Small features not printed  Scars on top surface  Blobs and/or pimples on exterior surface 
Weak infill  Stops extruding in the middle of a print  Infill showing on exterior of print 

Table of Contents

The guide is organized into a table with the following format. 

Issue/Title This highlights the action of a printer or print result that is not optimal or correct. This is comparable to a medical examination where the doctor inquires about the symptoms or behavior the patient is exhibiting or experiencing while being ill.
Example Image/Graphic This is an image or graphical representation of the issue.
Issue Details This provides additional information on the issue from actions during printing or the results upon completion.
Cause and Suggested Solutions This lists in order from highest to lowest probability the source or cause of the issue and suggested solutions to follow for issue resolution.

Not extruding at the start of the print
Print not sticking to bed
Jammed nozzle/clogged extruder
Pillowing, e.g. incomplete top layer fills, top layer holes/gaps
Smashed first layer, aka elephant’s foot; bulging first layer
Warping or corner lifting
Layer separation or warping within the part
Shifted layers or leaning prints
Stringing / hairy prints
Overhangs or sagging sections in the print
Support material difficult to remove
Under extrusion, e.g. not extruding enough plastic or insufficient material
Grinding filament and/or extruder motor skipping
Small features not printed
Scars on top surface
Blobs and/or pimples on exterior surface
Weak infill
Stops extruding in the middle of a print
Infill showing on exterior of print

How to Level Your Print Bed

If you are specifically running into issues that relate to having an unlevel printing surface, please refer to our Anatomy of a 3D Printer: Bed Leveling article - it has comprehensive solutions for any type of leveling system!

Click here: The Anatomy of a 3D Printer: Bed Leveling

Troubleshooting Guide

Not Extruding At The Start Of The Print

Issue/Title

Not extruding at the start of the print

Example Image / Graphic

Not Extruding

Issue Details

Print grooves left in bed with no filament and/or flaky or intermittent lines of filament on the first and subsequent layers

Cause 1

Incorrect extruder calibration/offset

Suggested Solutions 1

  1. Prime extruder

  2. Adjust nozzle height

  3. Adjust first layer height

  4. Adjust filament extrusion width

  5. Babysteping; Z offset

Cause 2

Clogged extruder/nozzle

Suggested Solutions 2

  1. Hobbed gear

  2. Clear nozzle

Print Not Sticking To Bed

Issue/Title

Print not sticking to bed

Example Image / Graphic

Not Stuck

Issue Details

Insufficient bed adhesion

Cause 1

Bed is not level

Suggested Solutions 1

  1. Level bed

  2. Reduce print speed (first layer speed)

Cause 2

Incorrect nozzle calibration/offset

Suggested Solutions 2

  1. Adjust nozzle height

  2. Adjust first layer height (Use baby-stepping to ensure proper first layer height)

Cause 3

Improper bed surface or settings for filament

Suggested Solutions 3

  1. Change bed surface (glass/tape/BuildTak)

  2. Use adhesives (tape/glue/hairspray)

  3. Adjust bed temperature (for some materials)

  4. Adjust extrusion temperature

  5. Pro Tip - Use raft and brim

Jammed Nozzle / Clogged Extruder

Issue/Title

Jammed nozzle/clogged extruder

Example Image / Graphic

Issue Details

Extruder is unable to feed filament through nozzle and is often accompanied by a grinding or “clicking” sound from the feed motor

Cause 1

Heat creep for PLA

Suggested Solutions 1

  1. Manually push filament through extruder

  2. Reload filament

  3. Cool extruder and reheat

Cause 2

Particle or carbonized filament blocking nozzle

Suggested Solutions 2

  1. Clear with small diameter needle, e.g. acupuncture needle

  2. Nylon cold pull

  3. Disassemble extruder and nozzle

  4. http://forums.matterhackers.com/topic/39/unclogging-nozzles

Pillowing, e.g. incomplete top layer fills, top layer holes/gaps

Issue/Title

Pillowing, e.g. incomplete top layer fills, top layer holes/gaps

Example Image / Graphic

Pillowing

Issue Details

Pillowing is usually PLA filament specific

Cause 1

Layer cooling too fast for PLA

Suggested Solutions 1

  1. Increase the number of top layers

  2. Increase infill density

  3. Lower speed for solid top layers

Smashed first layer, aka elephant’s foot; bulging first layer

Issue/Title

Smashed first layer, aka elephant’s foot; bulging first layer

Example Image / Graphic

Issue Details

Side profile of the printed part shows a bow near the bottom or next to the surface that was adjacent to the print bed

Cause 1

Bed is not level

Suggested Solutions 1

  1. Level bed

Cause 2

First layer height is too low

Suggested Solutions 2

  1. Increase first layer height

  2. Balance height adjustment with first layer quality

Cause 3

Extrusion rate for the first layer is greater than 100%

Suggested Solutions 3

  1. Adjust first layer extrusion rate

  2. Pro Tip - Design a chamfer into the part

Warping or corner lifting

Issue/Title

Warping or corner lifting

Example Image / Graphic

Issue Details

Edge near the bottom of the print or surface adjacent to the print bed is not level or flat

Cause 1

Materials, e.g. ABS and Nylon may shrink upon cooling and/or curing

Suggested Solutions 1

  1. Level bed

  2. Use glues/adhesives on borosilicate glass

  3. For ABS, use BuildTak, WolfBite, or ABS “juice”

  4. Use baby-stepping to ensure proper first layer height

  5. Pro Tip - Use Enclosure for environmental control

  6. Pro Tip - Keep printer away from air vents

Cause 2

Design of part has sharp corners or thin areas

Suggested Solutions 2

  1. Level bed

  2. Use baby-stepping to ensure proper first layer height

  3. Design “lily pads” for suspected problem areas and integrate into the model

Layer separation or warping within the part

Issue/Title

Layer separation or warping within the part

Example Image / Graphic

Issue Details

Layers do not adhere to previously printed layers and pulls from print bed

Cause 1

Print temperature is set too low

Suggested Solutions 1

  1. Adjust print temperature higher

Cause 2

Too much layer cooling during and after deposition

Suggested Solutions 2

  1. Disable layer cooling

Cause 3

Ambient air temperature is too cold and uneven

Suggested Solutions 3

  1. Use an enclosure, e.g. cardboard box or shower curtain to control environment

Cause 4

Printer is printing too fast

Suggested Solutions 4

  1. Decrease print speed

Shifted layers or leaning prints

Issue/Title

Shifted layers or leaning prints

Example Image / Graphic

Issue Details

Layers shift in the z-direction as print progresses

Cause 1

Printer is printing too fast

Suggested Solutions 1

  1. Lower printing speed

Cause 2

There nozzle is getting caught on raised or warped sections of the print

Suggested Solutions 2
  1. Change your Z-Lift to be a small positive number so the nozzle will be above the part during moves. A good number for most printers is 1mm or approximately 5 layers.

Cause 3

There are loose pulleys on the x-axis and/or y-axis

Suggested Solutions 3

  1. Make sure there is no “play” in the pulleys and tighten

  2. Check to see if there is friction on the pulleys and adjust

  3. http://forums.matterhackers.com/topic/76/how-to-fix-shifting-layers

Cause 4

Belts are skipping teeth on the x-axis and/or y-axis

Suggested Solutions 4

  1. Check for friction along the entire axis

  2. Check that belts are tight and adjust tension screw

  3. http://forums.matterhackers.com/topic/76/how-to-fix-shifting-layers

Stringing / hairy prints

Issue/Title

Stringing / hairy prints

Example Image / Graphic

Issue Details

Filament in the hot end of the extruder continues to ooze out of the nozzle during non-print moves

Cause 1

Slow extruder movement between sections of a part or more than one part

Suggested Solutions 1

  1. Retraction calibration

  2. Increase extruder speed on non-printing movements

  3. Retraction: Just say "No" to oozing

  4. Retraction Cubes download

Cause 2

Length of filament retraction is too short

Suggested Solutions 2

  1. Retraction calibration

  2. Increase length of filament retraction

  3. Retraction: Just say "No" to oozing

  4. Retraction Cubes download

Cause 3

You are printing with PET

Suggested Solutions 3

  1. Use dry filament

  2. Adjust extruder temperature

Cause 4

Printer crosses gaps when moving from one place to another

Suggested Solutions 4

  1. Turn on avoid crossing perimeters

Overhangs or sagging sections in the print

Issue/Title

Overhangs or sagging sections in the print

Example Image / Graphic

OverHangs

Issue Details

Unsupported or protruding part faces may not print properly or not print at all

Cause 1

Design of model or positioning of part

Suggested Solutions 1

  1. Add supports

  2. Reduce layer heights

  3. Slow speed

  4. Reposition model for better printing

  5. Keep overhangs typically at a 45 degree angle or less

Support material difficult to remove

Issue/Title

Support material difficult to remove

Example Image / Graphic

Issue Details

Removing supports is difficult due to fused support material with the initial part layers and often results in pitted initial layers once supports are removed

Cause 1

No gap or layer height offset between support layer and initial part layer

Suggested Solutions 1

  1. Increase air gap

  2. Increase the pattern spacing

  3. Decrease the support percentage

  4. Turn off create perimeter

Under extrusion, e.g. not extruding enough plastic or insufficient material

Issue/Title

Under extrusion, e.g. not extruding enough plastic or insufficient material

Example Image / Graphic

Issue Details

Under extrusion is identified by “silky” residue or gaps between extrusion lines or layers

Cause 1

Printer settings for filament size is incorrect

Suggested Solutions 1

  1. Measure filament diameter

    1. Change filament extrusion multiplier to compensate on the fly

    2. Some machines require 2.85 mm filament instead of 3.00 mm filament (Airwolf, Ultimaker).

Cause 2

Filament extrusion temperature is too low

Suggested Solutions 3

  1. Increase extruder temperature

Cause 3

Nozzle or extruder may be clogged or not properly calibrated

Suggested Solutions 3

  1. Check that the filament path is clear

  2. Clear nozzle and/or extruder

  3. Calibrate your extruder

    1. Calibrating a Makerbot

Grinding filament and/or extruder motor skipping

Issue/Title

Grinding filament and/or extruder motor skipping

Example Image / Graphic

Issue Details

Noise from the feed motor makes a grinding or clicking sound

Cause 1

Heat creep from the extruder that creates a “bulb” at the end of the filament between the gear and the extruder

Suggested Solutions 1

  1. Check that filament is extruding

  2. Increase extruder temperature

  3. Clear nozzle jam

  4. Check extruder motor and hobbed gear for filament residue

Small features not printed

Issue/Title

Small features not printed

Example Image / Graphic

Issue Details

Small details such as sharp corners, thin walls, or intricate designs are not fully formed or are missing in the final print. This can often be seen in highly detailed models or prints with small, intricate parts.

Cause 1

Features are below the nozzle extrusion width is the most common cause of this issue

Suggested Solutions 1

  1. Turn on thin wall detection. This is sometimes call aracne in Cura and Prusa Slicer.

  2. If you have access to the source files, re-model the walls with more thickness.

Scars on top surface

Issue/Title

Scars on top surface

Example Image / Graphic

Issue Details

Filament residue is “leaked” upon the top of the print surface

Cause 1

Lack of z-lift or retraction between moves

Suggested Solutions 1

  1. Increase z- lift

Blobs and/or pimples on exterior surface

Issue/Title

Blobs and/or pimples on exterior surface

Example Image / Graphic

Issue Details

  The exterior surface of the print has small, unwanted extrusions or bumps, often referred to as blobs or pimples. These can occur randomly or at consistent intervals, disrupting the smooth finish of the print. They can vary in size and are usually more noticeable on the surface of the print.

Cause 1

 Incorrect retraction settings and/or temperature fluctuations

Blobs and pimples often occur when the printer retracts the filament too slowly or not far enough, causing excess filament to leak out of the nozzle. This can also be caused by inconsistent temperature control, where the heat from the extruder causes the filament to ooze out in unwanted areas.

Suggested Solutions

  1. Clean nozzle

  2. Adjust the retraction length and speed

  3. Check connection (USB)

  4. Pauses, try printing from SD

Weak infill

Issue/Title

Weak infill

Example Image / Graphic

Issue Details

  The infill of the print, which provides internal support, is not strong or dense enough. This may result in a print that is weak, flimsy, or more susceptible to breakage. The infill may appear sparse, incomplete, or may not adhere properly to the rest of the print.

Cause 1

  

Incorrect infill settings and/or low print temperature

Weak infill is often caused by incorrect infill settings in the slicing software, such as a too low infill density or an inappropriate infill pattern for the specific print. Additionally, a print temperature that is too low can lead to poor layer adhesion, resulting in a weak infill structure.

Suggested Solutions 1

  1. Change infill pattern

  2. Lower print speed

  3. Increase infill extrusion width

Stops extruding in the middle of a print

Issue/Title

Stops extruding in the middle of a print

Example Image / Graphic

Issue Details

 The printer abruptly stops extruding filament during the print process. This can result in incomplete prints, with layers missing from the point of stoppage. The issue can occur at any point during the print and can affect any part of the model being printed.

Cause 1

  

Filament feed issues and/or extruder hardware problems

The printer may stop extruding if there are issues with the filament feed, such as the filament running out, getting tangled, or being stripped. Additionally, hardware problems like a jammed nozzle or heat creep (where heat travels up the extruder, causing the filament to soften and jam before it reaches the nozzle) can also cause the printer to stop extruding.

Suggested Solutions 1

  1. Out of filament

  2. Filament tangle before extruder

  3. Stripped filament

  4. Nozzle jam

  5. Heat creep

Infill showing on exterior of print

Issue/Title

Infill showing on exterior of print

Example Image / Graphic

Issue Details

Infill structure is visible on the top, bottom or sides of a printed part

Cause 1

Infill shows on top or bottom surfaces due to insufficient number of top/solid bottom layers or wrong layer speeds

Suggested Solutions 1

  1. Increase number of surface layers

  2. Decrease top solid infill speed

Cause 2

Infill shows on side surfaces due to insufficient number of perimeters or too much infill overlap

Suggested Solutions 2

  1. Increase number of perimeters

  2. Decrease infill overlap