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.

If you need some extra guidance, you can always book a virtual training session with our services team - professional development training and support. 

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
Issue 14Small 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

Person inspecting a print inside an enclosed FDM 3D printer

Troubleshooting Guide

Not Extruding At The Start Of The Print

Issue/Title Not extruding at the start of the print
Example Image / Graphic Clear filament first layer on blue painter’s tape build surface
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 Failed first layer print on blue painter's tape
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 Clogged 3D printer hotend with burnt filament buildup
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

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 Gray 3D printed cube with sparse top infill holes
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 White 3D printed cube on a blue print bed
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 White 3D printed pyramid on blue painter’s tape
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 Yellow 3D printed cube with visible layer lines
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 Red 3D printed bracket with mounting holes and visible layer lines
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
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

Stringing / hairy prints

Issue/Title Stringing / hairy prints
Example Image / Graphic Yellow 3D printed stringing test with thin strands between towers
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 Blue 3D printed overhang angle test model
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 Removing support material from a translucent 3D print
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 Red 3D print showing severe stringing across the top
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 Aluminum 3D printer extruder drive feeding green filament
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 3D printed MatterHackers logo test prints with dime for scale
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 Gray 3D printed calibration cube with visible top infill and layer lines
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 Black FDM 3D print showing layer defects and rough surface finish
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 Red 3D print showing triangular infill on a blue print bed
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 White 3D printed part with visible layer lines and stringing on the corner
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 3D printed gray bracket with cylindrical mount on blue print bed
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