They spin an imported STL/OBJ's **starting orientation** in exact 90° steps about each axis, then re-slice and rebuild the cut automatically so the preview updates right away.
Use them to align the model's long axis with your chosen rotation axis, to set which face the first cut hits, or to fix exporter quirks (lots of programs export Z-up while the tool works Y-up — one press about X usually sorts it). The 90° steps are exact, so click around freely; there's no drift.
They act on the most recently imported model — for flat 2D profiles there's no 3D orientation to set (in-plane spin lives in the OBJECT bar's ROTATE field instead).
Use them to align the model's long axis with your chosen rotation axis, to set which face the first cut hits, or to fix exporter quirks (lots of programs export Z-up while the tool works Y-up — one press about X usually sorts it). The 90° steps are exact, so click around freely; there's no drift.
They act on the most recently imported model — for flat 2D profiles there's no 3D orientation to set (in-plane spin lives in the OBJECT bar's ROTATE field instead).