Koz Ross on Nostr: Maybe someone who understands how #FreeCAD 1.0's Assembly works can explain this to ...

Maybe someone who understands how #FreeCAD 1.0's Assembly works can explain this to me, because I don't get it at all.

1. I add the HGR15 rail, set it to grounded.
2. I add the HGH15 carriage, set it to have a slider joint between the top face of the rail and the bottom face of the carriage that is meant to touch it.
3. I add the square section of steel and set it to fixed (or distance 0, doesn't matter) against the carriage.

The carriage and the section don't co-move. Why? (cont.)