Got a Raspberry Pi cluster with PoE and tired of messy, improvised setups? I’ve designed a clean, modular system to mount 4 Raspberry Pi boards with SSDs and a 5-port PoE switch—all in just 1.5U of a 19” rack. This fully 3D-printed project, redesigned from the ground up (not compatible with previous models), is built for order, accessibility, and airflow. Each Raspberry Pi gets its own removable tray with space for a PoE HAT and boot SSD. The trays slide smoothly into place, and a dedicated enclosure houses the gigabit PoE switch—everything mounted on simple M5 threaded rods, no extra metal chassis needed. Even better: all parts are optimized for support-free FDM printing, saving you time and filament. Concerned about thermal build-up? So was I—there are recommendations for materials (use ABS for key parts), fan control, and I’m already prototyping a new vertical layout that improves airflow dramatically, still within 1.5U. Turn your rack into a clean, professional-grade Pi cluster!