Kicad is oriented to PCB production. This hardly looks like a PCB application so I wonder if Kicad is the right tool to think about using? Maybe a regular CAD program? I’m not saying Kicad can’t be used but normally delicate shaping is recommended to be done in Freecad with the help of @maui 's Kicad StepUp: a Seamless ECAD/MCAD PCB Data Integration