create_assembly

Combine already-built CAD parts into one named multi-part assembly STEP at user-given positions, check that the parts, names and placements came out right, and commit the assembly to the twin linked to its part items. Use when the user asks to assemble, put together, stack or mount committed parts (for example a bracket on a plate, a gripper from its fingers and base, an arm from its links), or a design phase needs an assembly cad_model built from part cad_models.