A stackable sorting box system, with and without intermediate walls, that you can customize to the size you are looking for in FreeCAD.

Simply change the values in the spreadsheet in FreeCAD and the different versions will update to your specified size.

If you half the length or the width on a second set of boxes, you can stack 2 boxes into one.

Parameters

Use at least 4 times (I would suggest 5x) the nozzle size as wall thickness (e.g.: 1,6 mm for a 0,4 mm nozzle).

The corner radius must be bigger than the wall thickness otherwise FreeCAD will not recalculate the parts correctly. 

If you encounter a problem during recalculation, try increasing the radius this solved the issue, the one time I had one, for me. 

Print settings

You don't need supports.

Every material should be fine.