Stop and describe what happened
Ask the supervising adult to stop a failed print safely. Do not reach into a moving printer. When the machine and part are safe to inspect, write down what you see: a lifted corner, a missing detail, loose strands, or a part that does not fit. A clear observation is more useful than simply saying the print is bad.
Compare the model and the preview
If a detail is missing, look for it in the model and then in the slicer’s layer preview. Very thin features or disconnected shapes may not appear as expected. If the preview already shows the problem, changing machine settings is unlikely to fix the design. Work with your instructor to strengthen or reconnect the feature.
Check the setup together
An adult can check that the selected printer, nozzle, and material profile match the equipment. Follow the manufacturer’s bed preparation and calibration guidance. There is no single temperature or speed that fits every machine and material. Do not make hardware adjustments without the right supervision and instructions.
Change one thing and keep a record
Choose one likely cause and one small change. Record the model version and the settings used, then compare the result. A small test can save time and material. If you change everything at once, it becomes difficult to know what helped. Your notebook is part of your maker toolkit.