I wanted to make a large, printable, modular shelving unit to take advantage of gridfinity and honeycomb storage, so I designed this! I originally designed it to use M3 and M5 screws and heat set inserts, but have also included alternate files for all M3 screws screwing directly into the plastic. The sides, back, and bottom need to be printed on edge diagonally to fit onto a 256x256 print bed. The hex side walls should be printed flat on the print bed. Print them first, and then when printing the sides and back, put a pause command in the slicer to stop just before it starts the giant bridge and slide the hex walls in. They have an orientation, the hex holes should be larger on the inside of the shelf than the outside. The bottom shelves needed to be split in half to be printable, and I made the gridifinity baseplate print seperately and be pushed on to the shelf so that you wouldn't need any support. The sides have mounting holes for the shelves at the top and bottom for flexibilty. Clearance holes have a diamond top and bottom to avoid the layers interfering with clearance, holes that are being screwed into or are having heat sink inserts mounted in them don't have this to maximize surface area.
I've attached a fusion archive of the original project file. Feel free to tweak it for your own hardware or make whatever changes you need!