L'électron rare
197c54e005
The owner proposes building the roof structure in V-SLOT extrusion, which fits the house ecosystem and makes the V-groove itself the sliding rail. Record it as the retained lead with its three guard rails: vibration-proofed joints, weather-protected rolling interface, and C-beam/4080 main beams sized by FreeCAD FEM for the deployed cantilever. Positive mechanical travel lock stays independent.