HighFDM
Warping: the part lifts and its corners curl up
The part's corners and edges separate from the bed mid-print and end up curled upward. The base stops being flat and, if the lifting continues, the head eventually knocks the part loose.
Troubleshooting
Identify the defect you are seeing and apply the right correction. Every problem lists its likely causes in order, the fixes with their real effort, and how to avoid it next time.
18 results
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18 results
Sorted by severity: what ruins the part comes first.
Severity: High (9)
HighFDM
The first layer will not stick to the bed
Filament comes out of the nozzle but does not stay down: it turns into spaghetti, drags behind the head, or leaves separated rounded lines that peel off on their own. In the worst case the print never gets going.
HighFDM
Under-extrusion: less material comes out than it should
Material lines are missing within layers: gaps appear between beads, walls look thin and translucent, and the part breaks easily. Prusa describes it as layers missing material and fragile parts that tend to fall apart.
HighFDM
Layer shifting: the print slides partway up
From a certain height upward the whole part appears shifted sideways relative to the bottom, as if somebody had pushed it. The break is clean and happens on the X axis, the Y axis or both.
HighFDM
Delamination: layers separate
The part opens along the layer lines: horizontal cracks appear, and under load it splits cleanly between two layers instead of breaking the material. It is most common on tall, thin parts.
HighFDM
Clogged nozzle: material stops coming out
The extruder turns or makes its characteristic click but no material comes out, or very little and irregularly. Prusa describes a partial clog as the case where the printer pushes some material but not enough, with gaps and incomplete layers, and with the filament curling up instead of coming out straight.
HighResina
Resin: the part does not stick to the build plate
At the end of the print the plate comes out empty, or with only part of the raft, and the part is found stuck to the bottom of the vat as a sheet of cured resin. Prusa documents it as prints breaking away from the platform.
HighResina
Resin: separated layers and parts split in half
The part appears cleanly cut along a horizontal plane, or shows cracks between layers. Prusa documents this failure specifically for resin printers and links it to the material's shrinkage after curing.
HighResina
Resin: wrong exposure, lost detail or no part at all
With too little exposure nothing appears on the plate or the part comes out soft and deformed; Prusa documents the case of 'print doesn't appear, resin does not solidify'. With too much, details thicken, holes close up, supports fuse solid and parts that should fit will not.
Severity: Medium (7)
MediumFDM
Stringing: threads and cobwebs between parts
Fine plastic strands are left between two parts of the model, or between two objects on the same plate. Prusa calls it 'hairy prints'. In severe cases the part is covered in a web you have to remove with a knife or heat gun.
MediumFDM
Over-extrusion: more material comes out than needed
Walls come out bulging and rough, top layers show piled-up material, holes print smaller than designed and parts that should fit will not go together. On print-in-place assemblies, moving parts end up fused.
MediumFDM
Blobs and zits: bumps on the surface
Small bumps or zits appear on the walls, almost always aligned vertically at the seam where each layer starts and ends. In severe cases a mass of plastic builds up around the nozzle and can ruin the whole print.
MediumFDM
Overheating: the part deforms on small areas
In areas where each layer is very small — points, thin towers, fine detail — the material looks melted, with rounded edges and a shiny, irregular surface. The geometry is lost and sometimes the part topples.
MediumFDM
Drooping overhangs and edges curling upward
Overhanging areas come out rough with drooping strands, and edges curl upward until the head strikes them. Bridges between two supports sag in the middle instead of running straight.
MediumFDM
Supports that will not come off or ruin the surface
Supports end up welded to the part and have to be prised off with pliers, leaving marks, gouges or stuck-on material. The surface they touched comes out rough and sometimes the part breaks during removal.
MediumResina
Resin: the part stays sticky after printing
The part feels tacky or oily to the touch even after washing, and leaves residue on your fingers and the table. In some cases the surface looks matte and soft, or micro-cracks appear after a long wash.
Severity: Low (2)
LowFDM
Elephant foot: the base comes out flared
The first layers protrude beyond the rest of the part, forming a lip around the base. The part does not sit flat, will not slot into its housing, and its lower dimensions are larger than designed.
LowFDM
Ringing or ghosting: echoes and ripples on the walls
After each corner or sharp change of direction, repeating ripples appear along the wall and fade out, like an echo of the previous feature. It shows up most on flat surfaces and around lettering or holes.