3D models
A 3D model is a media item that renders in the browser and can be rotated, zoomed and inspected. For machine documentation it replaces a page of photographs taken from angles nobody needed.
Why it earns its place
A technician looking for a terminal block does not want a photograph of the front. They want to turn the thing round. One model answers every question six photographs approximate, and it is one file to keep current instead of six to re-shoot when the housing changes.
Adding one
Upload the model as a media item of the 3D model type and place it on a page like any other media — in a field, in a layout, or through a listing.
Formats
The viewer is vendored, not fetched from someone else's CDN, and it handles the common exchange formats directly.
Some CAD formats need an importer, and importers are not free
A native CAD format usually needs an extra importer module. Those are deliberately not loaded by default: each one is a large download, and several want to fetch themselves from a third-party CDN, which the platform's content policy refuses. If you need one, it is vendored on request — a decision with a size and a licence attached, not a switch.
The practical answer for documentation is to export a neutral exchange format from CAD once, and keep that beside the drawing.
Size
A model is the largest thing a documentation page carries. It counts against the organization's storage quota, and it is worth exporting at the detail a reader needs rather than the detail the CAD file has — a housing at manufacturing tolerance is a slow page and no more informative.
Accessibility and fallback
A model is not readable by everyone or on every connection. Give it a caption that says what it shows, and keep the important detail in the text as well — the model is the convenient answer, not the only one.