What went wrong with your print?

3D Print Troubleshooting: Find the Fault by What You Can See What to look for Three cheap things diagnose most of what follows. A tool kit with nozzle needles, tweezers and hex keys… ABS Not Sticking to Bed: Chamber Heat First, Adhesive Second ABS not sticking to bed is a heat problem before it is an adhesion one. Chamber temperature, bed prep that survives 100 degrees, and when a brim is enough. ASA Warping: The Enclosure Is the Fix, Not a Hotter Bed ASA warping is solved by an enclosure, not by pushing the bed hotter. What chamber temperature it needs, why draughts crack layers, and when a brim helps. Blobs, zits and a visible seam line A small defect where each layer starts and stops, stacked into a visible line. Cracking and layer delamination Layers separate under load or on their own. Weak bonding from cold plastic or a cold chamber. Drooping overhangs and failed bridges Plastic sags before it sets. Cooling and slower perimeters do most of the work. Elephant foot on the bottom layer The first layers bulge outwards. Too much squish plus a bed hotter than it needs to be. First Layer Not Sticking: What 3D Printer Bed Adhesion Depends On Nine times out of ten the plate is contaminated with skin oil, not badly levelled. Wash it before you touch the Z offset. Layer shifting partway through a print Everything above a certain height is offset. Belts, grub screws or a speed the machine cannot hold. Nozzle clogged: partial and complete blockages A partial clog degrades quality gradually; a complete one stops everything. The cold pull handles both. PETG Not Sticking to Bed: Why It Is Usually the Opposite Problem PETG not sticking to bed is rarer than PETG sticking too hard. The nozzle gap it wants, why glue is a release layer here, and the temperatures that work. PETG Stringing: Why It Strings More Than PLA, and What Fixes It PETG stringing more than PLA is normal, not a fault. Why the material oozes, the retraction numbers that work, and why drying it matters far more here. PLA Not Sticking to Bed: The Four Causes, in the Order to Check Them PLA not sticking to bed is almost never the filament. Four causes in the order worth checking: bed height, a dirty plate, first-layer speed, and draughts. PLA Stringing: Why Dry PLA Still Strings, and the Settings That Stop It PLA stringing is retraction and temperature, in that order, and dry filament still strings if the settings are wrong. A test you can run in eight minutes. PLA Warping: Rare Enough to Be a Clue in Itself PLA warping is uncommon enough to be a clue in itself: it points at a draught, a cold bed or a tall thin part, not at bad filament. What to change, in order. Print detached mid-print and turned into spaghetti The part came off the plate and the nozzle kept extruding into air. Adhesion, warping or a knock. Ringing and ghosting on vertical surfaces Echoes of a corner repeating across the wall. Mechanical vibration the frame cannot damp fast enough. Stringing and oozing between parts Fine hairs across gaps. Moisture first, temperature second, retraction third — in that order.