My variant of a dry box uses the popular 22 liter IKEA Samla box. I use this box stacked twice on my Prusa Enclosure V2 - MMU2S to feed my MK3S and MMU2S with filament.

The whole construction has been modeled directly into a model of the Samla Box and therefore fits in nicely and so nothing slips around in the box.

But I also wanted the silica gel not to be under the filament spools in the spool holders like I had with the original MMU2S spool holders. It should be in its own container that you can take out separately.

You need this to build this drybox:

• ~ 500g PETG or PLA filament (I used transparent filament)
• ~ 12g for the spool rings for better grip
• 12x 608Z  Ball-bearing (included with MMU2S)
• 4x Alu Spool Rods (included with MMU2S)
• 4x M3 Nuts (optional if you use the TopSpoolholder and want to fix it)
• 4x M3 Hex Socket Screws (optional if you use the TopSpoolholder and want to fix it)

Print settings:

Besides the STL files, I have also attached 3mf PrusaSlicer 2.4.2 files that I used to print my copies. These have included all the necessary settings.

But basically all spoolholders are printed with 0.2mm and 10% infill, the spoolrods with 0.05mm and 15% infill for a good and stable run and the TPU rings for the spoolrods with 0.2mm layer height and vase mode. I didn't use support.
But feel free to adapt them to your purposes.

Assembly:

• Bottom Spool Holder
  Both bottom spool holders have two slots for M3 nuts. These do not really need support when printing, but afterwards you may have to clean the slots from filament so that the nut goes in nicely.
  When the nuts are inserted, there are clips to prevent them from falling out.
  
  If you use the printed spool rods, I printed them in 0.05 layer height to have a nice round run of the spool. The TPU rings, for better grip of the filament spool, are pushed onto the semi-axles as can be seen in the pictures. You need to have a little finesse for this task.
   
• Top Spool Holder
  There is not really much to say about the top spool holder, it is positioned using the centering bolts and can also be fixed with the M3 hex screws.
  
  If you use the printed spool rods, I printed them in 0.05 layer height to have a nice round run of the spool. The TPU rings, for better grip of the filament spool, are pushed onto the semi-axles as can be seen in the pictures. You need to have a little finesse for this task.
   
• Silica Gel Container
  Also not really something to say, the small ring handle with the barbs is attached in the middle of the lid.

Here is a short video of how the box is put together.

You can also have a look at my other models, some of which I used for my MK3S setup.

I hope you like this box and will serve you well.

happy printing and please post a make, i would really appreciate it :)