Common Print Failures and How to Fix Them

Jackson B.

When Prints Go Wrong

Every 3D printer operator has a gallery of failed prints. Spaghetti nests of plastic, warped bases that peel dramatically off the bed, blobs and zits on surfaces that should be smooth, these failures are universal rites of passage. The skill that separates experienced makers from beginners isn't avoiding failures entirely (you can't), but diagnosing them quickly and applying the correct fix. Most print failures fall into a small number of categories with well-understood causes and solutions.

The diagnostic principle: change one variable at a time. When a print fails, it's tempting to change everything simultaneously. But then you don't know what actually fixed it. Identify the most likely cause, change that single thing, and test again. This systematic approach saves more time than any other troubleshooting strategy.

Warping

The print is lifting off the bed at the corners or edges, often dramatically curling upward as higher layers are deposited. This is the most common failure with ABS, ASA, and large PETG prints. The cause: thermal contraction. As the bottom layers cool below their glass transition temperature, they shrink, pulling the corners up. The correction: keep the bed hot (85–110°C depending on material), use a large brim (5–10mm around the base), eliminate all draughts (a closed room is essential for ABS/ASA), and consider a printer enclosure. For chronic warping with ABS, see our dedicated ABS warping guide. Adhesives help: thin glue stick, Magigoo, or hairspray on the bed surface can provide the extra grip needed to keep the base down through the thermal contraction cycle.

Spaghetti / Mid Print Detachment

Upon returning to your printer, you find a tangled mess of plastic and a print that has been printing into the air for hours. The base of the print had detached from the bed, and the printer continued to extrude filament onto nothing, unaware of the situation. This is almost always a first layer adhesion failure. The fix: go back to basics, re-level the bed carefully (see our bed levelling guide), ensure the surface is clean and correctly prepared, and verify your Z offset is correct with a live-Z test print.

Stringing

Fine plastic hairs are stretched between different parts of the print, particularly between towers or protrusions with travel moves between them. Stringing is caused by ooze from the nozzle during travel. Primary fixes: lower the print temperature (the plastic oozes more when very hot); increase retraction distance and speed (pulls filament back to reduce pressure before travel moves); and enable "comb mode" (routes travel moves inside the model where possible). See our retraction guide and temperature calibration for systematic approaches.

Layer Separation

The print looks like it's peeling apart horizontally, layers that aren't bonded to each other. This typically indicates insufficient print temperature (layers aren't hot enough to bond to each other), excessive part cooling (rapid cooling prevents reflow bonding), or wet filament creating steam bubbles that interrupt the bond. Increase temperature by 5°C, reduce cooling fan speed, and dry the filament before reprinting. See our layer separation guide for material specific advice. After addressing the immediate issue, please refer to our filament storage guide to help prevent recurrence.