Prepare an STL: repair and verify a saved copy

Follow one complete example from an STL with a duplicate face to a saved, reopened copy. Use the steps to understand what changed and how to check your own output. For holes, missing geometry or a slicer-only problem, start with the matching diagnostic guide.

1. Establish what the input is meant to contain

Download the owned cube with a repeated face. It is intended to describe six cube surfaces, with 20-coordinate spans on all axes. The extra triangle repeats an existing face; it is not a wall to remove. Select millimetres only because this control was designed with that assumption. For an unknown customer file, ask for a reference dimension first.

Open it in the STL Viewer. A normal silhouette is expected because the repeated face covers an existing one. Visual appearance alone cannot establish that the exported triangle set is suitable for the next operation.

2. Interpret the finding before selecting cleanup

The input has 13 triangles. Run the quality check and inspect the repeated face and associated over-shared edges. Those are related observations, not necessarily independent design defects. A missing cube face would need a different decision because removing triangles cannot reconstruct the intended surface. An intentionally separate object also should not be removed merely because it is smaller.

3. Make the narrow change and save a separate file

In STL Repair, explicit standard cleanup uploads the selected file for server processing. Review the operation and the report before accepting the derivative. For this control, the local processor removed the one duplicate and wrote a separate STL. That does not imply support for every hole, intersection or ambiguous internal surface.

Keep the actual saved cleaned control beside the original. The retained output was produced with the local processor revision documented in the reproduction record. It is a software observation, not a claim about the currently deployed server.

4. Reopen the bytes you will hand off

Read the reopened server report, then compare both files in STL Compare. Their different bytes and triangle counts are expected. Inspect the surfaces and dimensions; do not use unchanged bounds alone to accept a complex real part whose local features might have changed. A sampled comparison cannot prove that every surface point is identical.

5. Finish the job in the intended slicer

Use the actual printer, material and intended orientation. Review the first layer, required walls and all affected layers, then record any support or functional checks outside the mesh report. This case contains no retained slice or physical print of the cleaned cube, so it establishes the file correction and saved-copy verification only.

If the derivative has changed dimensions, lost required geometry or acquired unexpected findings, reject it and return to the preserved original. For a different symptom, use slicing triage rather than stacking unrelated automatic repairs on the same copy.