Start a diagnosis with when the defect appears, where it appears and whether it repeats. Similar-looking defects can have different causes. This guide helps you choose a useful check, without treating a photograph as certainty or changing every slicer setting at once.
Record a starting point
Note the model, orientation, printer, nozzle, spool and exact profile. Add what has changed since a satisfactory result: material, surface, mechanical part or setting. If you have never obtained a reference result, say so rather than assuming the printer was calibrated.
Describe an observation: “corners lift after several layers” is more useful than “poor quality”. Save the project version before each correction. The cited Prusa procedures concern its equipment; mechanical work must follow your own printer’s manual.
Choose a first diagnostic branch
| Symptom | First check | Next direction if needed |
|---|---|---|
| Lines fail to adhere from the start | Compatible surface and profile | First-layer guide |
| Missing material in layers | Filament/nozzle profile and unobstructed spool feed | Drive, nozzle and hotend cooling according to the manual |
| Strings between areas | Profile and outside condition of the nozzle | Temperature, retraction or moisture according to documentation |
| Corners lift | Material/surface combination and environment | Thermal conditions, geometry and an appropriate brim |
Prusa describes under-extrusion as missing material and lists profile, nozzle, drive and filament causes. This supports several diagnostic branches; increasing flow to conceal an obstruction is not an automatic conclusion.
Stringing and lifted corners are different questions
In “Stringing and oozing”, Prusa links strings to travel moves with oozing and discusses temperature, retraction, residue and moisture. A retraction length found for another extruder architecture is not a value to copy. First recover the profile for the hardware actually installed.
“Warping” describes shrinkage and thermal differences as contributors to lifting. Its approach depends on material and geometry. Enclosing every print or increasing cooling for every part is therefore not a common rule. For ABS, the environment and emissions also matter: see the ABS reference.
Build a comparison that can support a conclusion
- Choose one priority symptom.
- State a hypothesis and its associated check.
- Use a limited trial reproducing the problematic area.
- Change one documented condition within the equipment’s limits.
- Record the outcome, conditions and decision to keep or undo the change.
Reasoning example, not a performed test: if strings remain unchanged after restoring the correct profile, that observation weakens the hypothesis of a customised setting being the sole cause. It does not identify moisture as a certain cause. Another comparison is needed to separate the possibilities.
Know when to request focused help
If simple checks do not resolve the problem, prepare photographs, the slicing project, software version and change log for support. Do not send only “it will not print”. FDM settings explain useful terms, while the first-layer guide covers initial observations. No personal printing result is claimed here.
Sources consulted
- Under-extrusion — Prusa Research
Accessed - Stringing and oozing — Prusa Research
Accessed - Warping — Prusa Research
Accessed