Open the model at 0xr.space, then on Home open the three-dot menu on its card and press Download STL. Every triangle it draws is written on your device as a binary STL in millimetres with Z up, the way Cura, PrusaSlicer and Bambu Studio read one, so the part lands upright at its size. Downloading needs an account, made with your email address and a 6-digit code.
STL holds one surface and nothing on it: colours, textures, points and lines are left out, and a rigged model is written in its rest pose. Splats, point clouds and models whose licence forbids it cannot be downloaded. An OBJ has no unit and its numbers are written as metres, so an OBJ drawn in millimetres comes out 1,000 times too big; check the size in your slicer.
No. The STL is written in the browser from the copy on your device. Signing in does not send the model anywhere.
Downloading a converted copy needs one, on every device. Opening, viewing and sharing a model do not.
The model is a splat or a point cloud, which has no triangles to print, or its licence does not allow downloading.
No. An STL has no colour. Keep the original 3MF for a multicolour print, or press Download GLB for a file that keeps materials and textures.
Yes. It is a binary STL with a normal for each triangle, which every slicer reads. Its header gives the model's name and says mm, Z up.