Nozzle Scraping or Hitting the Print

Document the failure and confirm that it matches this guide: The nozzle drags across infill, knocks the model, or leaves scratches on top surfaces.

Return extreme overrides to a known printer, nozzle, material, and slicer profile so the diagnosis starts from a stable baseline.

Check over-extrusion. Check for raised plastic.

Check warping or curled edges. Verify hotend and gantry tightness.

Inspect loose hotend or gantry. Reduce excess flow.

Rule out travel strategy or missing z-hop. Use Z-hop only when needed.

Change only the single setting or hardware condition supported by the evidence, then run a small test that reproduces the original failure.

Compare the test against the target condition, record the successful value, and save it in a printer/material profile before repeating the full print.