“We did not take it apart. This project had already eaten up around a week of free time, maybe a week and a half, and quite frankly nobody wanted to deal with it any more. We had succeeded in clearing the nozzle, and isolated the remaining problem to the hot end — good enough. We ordered another hot end and replaced the old one.”

Have you gone to print something really cool only to find that mysterious wrinkles had appeared? Unless your really cool 3D print needed a molten slag effect, those wrinkles and layer defects probably ruined it. But why? What are they? And how can you not have this happen again?