Print troubleshooting

Most failed prints aren't caused by the file but by the printer, the filament or the bed. Before you give up, find your problem below: each one says what it looks like and what to try, simplest first.

What helps in general: a clean bed, dry filament and the right printer and material chosen in Printypus (the file is prepared exactly for them).

Is it the file or the print?

Likely the print: the problem shows up randomly, elsewhere on the bed or with other models too; the part came loose, layers shifted, strings, bubbles, gaps in the walls.

Likely the file: the G-code preview is missing part of the model or has something extra, the size doesn't match what you set, or the same problem appears every time in the same spot even after cleaning and drying.

If you think the file we made is wrong, write to us with a link to the job and a photo of the print. contact@printypus.com

The first layer doesn't stick or looks bad

What it looks like: Lines don't join, they tear, or the nozzle drags across the bed; the model comes loose right at the start or drags the rest with it.

What to try:

Degrease the bed: wash it with warm water and dish soap or wipe it with isopropyl alcohol. Fingerprints are the most common cause.
Check that the right plate (smooth/textured PEI) is selected and that nothing lies on it.
Calibrate the nozzle height (Z offset / live adjust Z) or run automatic bed levelling.
For PETG on smooth PEI, use a thin layer of glue stick as a release agent.

Corners lift (warping), the part comes loose

What it looks like: Bottom edges and corners bend upwards during the print; the part rocks or comes off completely.

What to try:

Clean the bed and check the first layer (see above).
Print ABS and ASA in an enclosed printer, close the door and avoid drafts (window, air conditioning).
Large flat parts warp more: try shrinking them, splitting them, or turning them to rest on a smaller area.
Glue stick on the bed or a wider brim in the slicer helps.

Strings between parts (stringing)

What it looks like: Thin strands like a cobweb run between towers or across holes.

What to try:

Dry the filament: moisture is the usual cause with PETG and TPU.
Clean plastic stuck to the outside of the nozzle.
Fine strings can be removed after printing with a heat gun (briefly!) or trimmed off.

Gaps in walls and weak layers (under-extrusion)

What it looks like: Walls have holes, lines are thin and don't join, top surfaces have gaps, the part is light and brittle.

What to try:

Check that the sliced file uses the same material and filament diameter (1.75 mm) as your printer.
Make sure the spool unwinds freely and the filament isn't tangled or pinched.
Dry the filament.
If it gets worse, the nozzle may be partly clogged (see below).

Shifted layers

What it looks like: From a certain height the whole part is offset sideways like a step.

What to try:

The nozzle hit something: lifted corners, a broken support or a stuck blob. Fix the cause (warping, first layer).
Check that nothing blocks the movement (cables, spool, objects in the printer) and the belt tension per the maker's guide.
The printer should stand on a solid table that doesn't wobble.

Clogged nozzle

What it looks like: Little or no plastic comes out, the extruder clicks, the print stops forming midway.

What to try:

Heat the nozzle to the material temperature and push filament through by hand (load/unload in the printer menu).
Do a cold pull following your printer maker's guide.
If nothing helps, replace the nozzle; it's a consumable.

Wet filament

What it looks like: The nozzle crackles and hisses, the surface is rough and dull with bubbles, lots of strings, the part is brittle.

What to try:

Dry the filament (temperatures and times are listed with the materials).
Keep open spools in a sealed box or bag with silica gel.

Flared bottom layer (elephant's foot)

What it looks like: The first few layers are wider than the rest of the part, the bottom edge bulges and parts don't fit together.

What to try:

Usually the nozzle is too close to the bed: raise the Z offset by a few hundredths of a millimetre.
A lower bed temperature helps too.
On a finished part, the bulge can be trimmed with a knife or a file.

Supports won't come off or ruin the surface

What it looks like: Supports hold too firmly; after removal, leftovers remain or the surface above them is rough.

What to try:

Break supports off slowly with pliers or a flat screwdriver, ideally after the part has cooled.
If your model is already laid out to need few supports, choose “Keep as in the file” under Adjustments → Position and strength; or turn it differently in the model.
The surface above supports is always rougher; put the visible side up.

The part breaks between layers (strength and orientation)

What it looks like: Under load the part splits along a layer, e.g. a hook snaps at the bend.

What to try:

A 3D print is weakest between layers, i.e. along the print height. Orient the part so that pulling or bending acts along the layers, not across them: print a hook lying down, not standing up.
In Printypus: under “Will the part be pulled or bent?” in Adjustments → Position and strength, pick the direction of the force (an arrow in the preview shows it) and we lay the part so the force runs along the layers. Or choose “Keep as in the file” and orient the model in your design software first. Without a load, the automatic position looks for the fewest supports, not the most strength.
A tougher material helps as well: PETG is tougher than PLA.
For heavy loads choose a printer and material for higher temperatures (ABS/ASA in an enclosed printer) and keep the filament dry: moisture weakens the layers.

Detailed guides with photos are available from printer and slicer makers: Prusa Knowledge Base, Bambu Lab Wiki, Simplify3D Print Quality Guide.

Is it the file or the print?

Likely the print: the problem shows up randomly, elsewhere on the bed or with other models too; the part came loose, layers shifted, strings, bubbles, gaps in the walls.

If you think the file we made is wrong, write to us with a link to the job and a photo of the print. contact@printypus.com

The first layer doesn't stick or looks bad

What it looks like: Lines don't join, they tear, or the nozzle drags across the bed; the model comes loose right at the start or drags the rest with it.

What to try:

Degrease the bed: wash it with warm water and dish soap or wipe it with isopropyl alcohol. Fingerprints are the most common cause.
Check that the right plate (smooth/textured PEI) is selected and that nothing lies on it.
Calibrate the nozzle height (Z offset / live adjust Z) or run automatic bed levelling.
For PETG on smooth PEI, use a thin layer of glue stick as a release agent.

Corners lift (warping), the part comes loose

What it looks like: Bottom edges and corners bend upwards during the print; the part rocks or comes off completely.

What to try:

Clean the bed and check the first layer (see above).
Print ABS and ASA in an enclosed printer, close the door and avoid drafts (window, air conditioning).
Large flat parts warp more: try shrinking them, splitting them, or turning them to rest on a smaller area.
Glue stick on the bed or a wider brim in the slicer helps.

Strings between parts (stringing)

What it looks like: Thin strands like a cobweb run between towers or across holes.

What to try:

Dry the filament: moisture is the usual cause with PETG and TPU.
Clean plastic stuck to the outside of the nozzle.
Fine strings can be removed after printing with a heat gun (briefly!) or trimmed off.

Gaps in walls and weak layers (under-extrusion)

What it looks like: Walls have holes, lines are thin and don't join, top surfaces have gaps, the part is light and brittle.

What to try:

Check that the sliced file uses the same material and filament diameter (1.75 mm) as your printer.
Make sure the spool unwinds freely and the filament isn't tangled or pinched.
Dry the filament.
If it gets worse, the nozzle may be partly clogged (see below).

Shifted layers

What it looks like: From a certain height the whole part is offset sideways like a step.

What to try:

The nozzle hit something: lifted corners, a broken support or a stuck blob. Fix the cause (warping, first layer).
Check that nothing blocks the movement (cables, spool, objects in the printer) and the belt tension per the maker's guide.
The printer should stand on a solid table that doesn't wobble.

Clogged nozzle

What it looks like: Little or no plastic comes out, the extruder clicks, the print stops forming midway.

What to try:

Heat the nozzle to the material temperature and push filament through by hand (load/unload in the printer menu).
Do a cold pull following your printer maker's guide.
If nothing helps, replace the nozzle; it's a consumable.

Wet filament

What it looks like: The nozzle crackles and hisses, the surface is rough and dull with bubbles, lots of strings, the part is brittle.

What to try:

Dry the filament (temperatures and times are listed with the materials).
Keep open spools in a sealed box or bag with silica gel.

Flared bottom layer (elephant's foot)

What it looks like: The first few layers are wider than the rest of the part, the bottom edge bulges and parts don't fit together.

What to try:

Usually the nozzle is too close to the bed: raise the Z offset by a few hundredths of a millimetre.
A lower bed temperature helps too.
On a finished part, the bulge can be trimmed with a knife or a file.

Supports won't come off or ruin the surface

What it looks like: Supports hold too firmly; after removal, leftovers remain or the surface above them is rough.

What to try:

Break supports off slowly with pliers or a flat screwdriver, ideally after the part has cooled.
If your model is already laid out to need few supports, choose “Keep as in the file” under Adjustments → Position and strength; or turn it differently in the model.
The surface above supports is always rougher; put the visible side up.

The part breaks between layers (strength and orientation)

What it looks like: Under load the part splits along a layer, e.g. a hook snaps at the bend.

What to try:

A 3D print is weakest between layers, i.e. along the print height. Orient the part so that pulling or bending acts along the layers, not across them: print a hook lying down, not standing up.
In Printypus: under “Will the part be pulled or bent?” in Adjustments → Position and strength, pick the direction of the force (an arrow in the preview shows it) and we lay the part so the force runs along the layers. Or choose “Keep as in the file” and orient the model in your design software first. Without a load, the automatic position looks for the fewest supports, not the most strength.
A tougher material helps as well: PETG is tougher than PLA.
For heavy loads choose a printer and material for higher temperatures (ABS/ASA in an enclosed printer) and keep the filament dry: moisture weakens the layers.