Diagnose from the look
- Lines not sticking at all: nozzle too high, or greasy bed — clean with isopropyl alcohol and re-level
- Filament curling around the nozzle: nozzle too high, or draft cooling the plastic too fast
- Rough, torn surface: nozzle too low — raise the Z-offset by 0.02–0.05 mm
- Corners lifting: bed too cool, first layer too fast, or part needs a brim
- Elephant's foot: bed too hot or nozzle too low on layer one
The reliable recipe
Clean plate, 20 mm/s first layer, bed at the top of the material's range, and a 5–8mm brim for small footprints. Watch the first two layers complete before walking away — that habit alone saves more filament than any upgrade.
Warping: why corners lift
Warping is plastic shrinking as it cools — upper layers contract and peel the corners off the bed. ABS warps worst (ABS guide), PETG less, PLA least, which is one more reason beginners start with PLA+.
- Add a 5–10mm brim on anything with corners; raft for tiny footprints
- Run the bed at the top of your material's range
- Kill every draft — enclosure for ABS, closed room and no AC blast for the rest
- Clean plate plus the right adhesive: glue stick on smooth PEI, textured PEI bare for PLA
- Slow the first layer to 20 mm/s and watch two layers complete before walking away