Parametric Desiccant Box

I've been using Sterilite 18L and 19L bins for spool storage, cheap and locally available and a manageable size.

I adopted using alumina desiccant as my preferred humidity control, initially in cloth bags under RCNet's rack (https://www.printables.com/model/139303-sterilite-20-qt-gasket-box-spool-rack) but I found the space beneath the rack to be too restrictive for the cloth bags.  I then switched to Ayries rack remix (https://www.printables.com/model/1029030-filament-spool-rack-for-20qt-sterilite-container-d) which raised the spools sufficiently to allow for boxes of desiccant placed below.

Finally decided to design my own box after trying several. I was looking for a compact one that fully used the space without any overhanging features and fully open as possible without spilling desiccant.

Mine is designed in FreeCad and is fully parameterized. I've attached are photos of versions constructed from the same file. The small one for test purposes (50x70x20mm), a medium box (95x200x40mm), I assume 3 would fit in the storage bin and the larger one (148x215x40mm), two fit in the 19L storage bin.  Modified the rim size for the slot to make the lid fit easier and print more reliably.

Update: Added a 132x215x40mm version that fits the 18L (19Qt) Sterilite box, which slightly smaller in volume yet still fits 4 standard size 1 Kg spools.

Using PrusaSlicer, I use a infill based print without top and bottom layers to achieve the most open box (all sides are open). I found that a 15% gyroid infill had alumina sticking to the inner surface when it was emptied, so I bumped the infill to 20% for safety (YMMV with other infills and desiccant). I use a wall thickness of 2.2 to 2.4 mm for sufficient gyroid layers and stability.

I've included a few pre-selected sizes, but you can use the FreeCad file to create your own, or you can request new sizes from me!

The parametric FreeCad design allows for customization. All the main dimensions are in variable table for easy editing. Currently using a weekly appimage build, so if there are any issues let me know.