The guide includes diagrams for mounting cable trays on walls using pre-fabricated flanges or channels, laying cables, and selecting the appropriate material and finish for the environment and application. Just gonna preface this by saying we didn't install this and none of my guys broke this. The only. Add cable tray and conduit to your design with or without fittings. Fittings can also be added after drawing a segment or run. What is Cable Tray Design and Wiring Planning? At its heart, Cable Tray Design, Layout means choosing and. Building a custom cable tray is a great way to keep your space organized. First, gather sturdy materials like metal or plastic, along with tools like a saw and drill.