The existing shelves lacked consistency with the original container by Preb, so I designed a parameterized version that uses the same latches as the box to hold the shelf segments together.

The top plate can also function as a Gridfinity baseplate (no magnets, unfortunately, but I could look at adding them if it's requested). I opted for the lite grid to conserve material, and even with a fully loaded 6x6 box of my own, they’ve proven to be strong enough.

Instead of a backing, I included nubs that interface with the boxes as they slide in, holding them in place and easily disengaging with a slight pull on the box.

Printing:

No supports required! You'll need as many bases as you want shelves and a single top.

Parametric settings:

Edit the "Grid_X", “Grid_Y”, and “GridfinityUnit” parameters to match your box size. Edit the “Case_Quantity” parameter to the number of shelves you require or print the base as many times as needed.