See the module customizer here: https://www.thingiverse.com/thing:6001641
I recommend using the customizer built into OpenSCAD itself, the one on thingiverse doesn't render some of the labels and checkboxes.

This is a recreated and improved version of MartinMajewski's Modular Sorting System. It is a fully customizable case for small (or not so small) parts. It uses modules (small boxes) with dimensions based on a unit size (1 unit = 2 cm) that can be arranged in any way inside the case. Compared to the original, this version:

• Is customizeable in every way I could think of
• Has fully redesigned hinges, since the original hinges don't work for smaller cases (as they rely on the flexibility of the case to snap together)
• Has a clip to hold the box closed, partly inspired by Box M3, M4, M5 by stenc55.

The pattern on the lid as seen in the photo was made in PrusaSlicer by using a modifier mesh with 0 top and bottom layers and a hexagonal infill. The tiny cases scattered around are all of my test prints. You can print a small one too to make sure all the tolerances work on you printer (the tolerances are all exposed in the customizer).

Instructions

The main case is printed in two parts (base and lid) that snap together afterwards, and the modules are printed separately. To snap the base and lid together, put them both on a table as if the case was in the open position, and push them together. The lid also has a clip, which has a hinge that is printed in-place. The hinge parts tends to stick together during printing, so afterwards they take a bit of force to get rotating nicely (the tolerances there are customizable).

I printed my cases in PLA and PETG at 0.2mm layer with a brim to prevent warping. No supports needed.

Related:

Another remix of MartinMajewski's Modular Sorting System: https://www.printables.com/model/7687-modular-storagesorting-system
This project on printables: https://www.printables.com/model/467793-customizable-modular-storage-case