Local STL geometry screen
STL Wall Thickness Checker
Estimate wall thickness at sampled STL surface locations. Confirm the coordinate unit, choose a review threshold and inspect flagged locations before checking important features in CAD and your slicer.
Choose an STL
ASCII and binary STL files up to 25 MiB are supported. Your file is processed in this browser.
Try an example
Why can sampled thickness and slicer paths tell different stories?
Settings: STL coordinate unit mm; review threshold 1.2 mm. Slicer experiment: 0.4 mm nozzle, 0.2 mm layers, 0.45 mm width, two perimeters, zero infill, thin-wall option off.
Downloads this public control, then opens it locally. Your own file can still be chosen above.
Read the explanation · Download and compare controls · Methods and processing
Download the thin-bar STL control
How to act on a sampled result
| Observation | Next action |
|---|---|
| Measured sample below threshold | Inspect that geometry and the same sliced region. Compare nominal line widths only after checking the actual wall. |
| No measured sample below threshold | Review unmeasured locations and critical features that finite sampling can miss. |
| Unmeasured sample, possibly alongside a thin sample | Inspect open, degenerate or ambiguous geometry in CAD and the mesh viewer. |
| No valid measurement | Check unit, geometry and method limits; no zero or success is implied. |
| File could not be analysed | Choose a supported nonempty STL within the file limit and try again. |
Method boundary
The checker selects up to 2,000 triangles across input triangle order and casts one inward normal ray from each centroid. Degenerate faces and rays without an accepted opposing hit remain unmeasured. Unsampled triangles receive no estimate. A ray may hit another body, so this is neither a per-part result nor a whole-model minimum certificate. Read the sampling method.