I needed a storage system for small spare parts like screws, magnets, electronic components etc. And I collect the card board boxes of my filament orders, because “… you never know when you gonna need them…” :) 

The original gridfinity uses a 42 mm grid, that does not fit well into the cardboard boxes of bambu filament WITH SPOOL… Yes, with spool! Because these boxes are bigger than those of bambu filament refill packs without spools…

I changed the grid size, experimented with different heights until I found a working combination of “full height” (=full cardboard box height) and half height boxes, together with a base grid. You can combine in one cardboard box full height inserts next to two layers of half height inserts, as you like… My print profile is tested and includes all possible inserts (but a 5x5 box… but why would you need that one, you could just use the cardboard box as it is…). I cahnged the corner round to make grabbing small peaces out of the inserts easier…

Try for yourself and tell me, if something not works out for you…