Hi! I made an under-desk shelf to store the things those I was always scattering all over the table)) You can check the dimensions and the required materials in the pictures. Also, note that there are two options — with a notch and without one. ( I originally made the one with, because my tabletop has a mounting bracket that interferes with the bracket.)

UPD. May 4, 2025: I recommend printing the shelf horizontally, since that's how I designed and tested it, and it works great. However, if you prefer to print both shelves together in a vertical orientation, please use the file named Shelf_for_vertical_printing — it includes extra tolerance to account for plastic overhang artifacts during vertical printing (I didn't test it, so feel free to share results.)