Guides
Checking scale when importing an STL
Use the documented units and a known dimension to avoid scale mistakes with Cartesian's sample meshes.
STL coordinates need an interpretation
STL stores mesh coordinates without a standard declaration of physical units. A receiving application must decide what a coordinate value means. If one tool assumes metres and another assumes millimetres, an object can appear one thousand times too large or too small.
The Cartesian sample downloads label STL coordinates as millimetres and 3DM coordinates as metres. Those labels are part of the handoff information; keep them with the file when sharing it.
Check a dimension before rescaling
Set the receiving application's import units to the documented unit, then measure a known dimension or inspect the bounding size. For a numerical reference, one metre is one thousand millimetres. A ten-metre span corresponds to ten thousand millimetres.
If the size is wrong, determine whether the importer interpreted the coordinates incorrectly or whether you intentionally want a scale model. Correct the unit interpretation first. Apply a model-scale factor only after the full-size dimensions are understood.
Scale changes more than the overall size
A scaled mesh also scales wall thickness, gaps and small details. A connection that looks clear in a full-size model may become too thin or too close for a particular printer when reduced.
Use the slicer's inspection tools and the printer/material requirements to check the result. Inspect mesh closure, orientation and support needs separately. The public Cartesian files are studies and do not establish that a particular print will succeed.