Uses 0.5in PVC Pipe, wall mounted, use as many printed pieces as necessary to hold your filament, I used three printed pieces. Print in PETG for optimal results, but PLA should work for smaller shelves. I printed two of these, but I'm planning on making another one to fit all my filament :)

I'm considering redesigning this to accommodate the A1 Mini's smaller bed size, let me know if you want me to!