Anomalies
- First Layer Adhesion Failure The part detaches from the build plate during printing. Leads to spaghetti if undetected.
- Backlash Artifacts Dimensional errors and surface defects that appear specifically when an axis reverses direction. Circles become ovals, holes are the wrong size.
- Blobs / Zits Small bumps on the surface at points where the nozzle starts, stops, or restarts extrusion. Most visible along the Z-seam line.
- Bridge Sag Unsupported horizontal spans (bridges) droop in the middle, creating a V or U-shaped sag between support points.
- Clogging / Partial Clog Nozzle fully or partially blocked. No extrusion (full clog) or reduced, inconsistent extrusion (partial clog).
- Layer Separation / Delamination Layers don’t bond to each other — the part splits along layer lines under stress or even spontaneously during printing.
- Elephant Foot The first few layers of the print are wider than the rest — the bottom of the part bulges outward like an elephant’s foot.
- Ghosting / Ringing Ripple pattern on surfaces near sharp features — an echo of corners, letters, or holes repeated as a decaying wave across flat walls.
- Grinding / Stripping The extruder drive gear chews through the filament instead of pushing it forward. Once a groove is carved, the gear loses grip and extrusion stops entirely.
- Heat Creep Heat travels too far up the heatbreak, softening filament before it reaches the melt zone. Eventually causes a jam.
- Layer Shift A sudden horizontal offset — all layers above a certain point are shifted sideways. The print continues but in the wrong position.
- Over-extrusion Too much material deposited — excess plastic has nowhere to go, so it bulges outward, upward, or accumulates on the nozzle.
- Pillowing Bumpy, uneven top surface — small dimples or bumps where the top shell bridges over infill gaps below.
- Rough Overhangs The underside of overhanging features is rough, droopy, or curled. Quality degrades progressively with steeper angles.
- Scarring / Nozzle Marks Scratches or drag marks on top surfaces from the nozzle dragging across already-deposited material during travel moves.
- Spaghetti The print detaches and the printer keeps extruding into air — producing a tangled mess of filament. The most wasteful failure mode.
- Stringing / Oozing Thin threads of plastic stretched between features during travel moves. Ranges from fine hairs to thick strings.
- Thermal Shock Cracking Cracks forming in the part during or after printing from thermal stress. The part appears solid but has internal fractures along layer lines.
- Under-extrusion Not enough material deposited — the printer commands X amount of plastic but less comes out of the nozzle. Results in gaps, thin walls, and structurally weak parts.
- Warping Corners and edges of the print curl upward, lifting from the bed. In severe cases, the part detaches entirely.
- Wet Filament Artifacts Popping, bubbling, and rough surfaces caused by moisture trapped in the filament turning to steam inside the melt zone.
- Z-Banding / Z-Wobble Regular horizontal lines or ridges at consistent Z intervals. Visible and tangible on the surface of the print.