Design Concept

These dry boxes are designed to maintain filament quality by absorbing moisture from the air inside the CFS box.
It helps me to maintain less than 20% moisture in the CFS, while the room is at > 60% moisture.

Dry fillament is a must for good quality prints, and the CFS lacks moisture regulation...

Update July 2025:
Since we had a period with high humidity, the 40mm version did it's job and kept it around 20%. But I wanted less, so I've created the mother of all dryboxes: a huge 75mm version that just fits inside the CFS. It holds double the amount of sillica compared to the 40mm version. I added pictures and print files for that version.

So, there are 3 versions:

- For low humidity -> use the 25 mm version
- For normal humidity -> use the 40mm version
- For high humidity -> use the 75mm version.

Note:

This model is optimized for printing, I did that by making sure it does not need any supports at all, and made sure the slots are horizontal instead of veritical, so your printer can do bridges instead of dozens of vertical pillars.

Use:

Print, assemble and install the dryboxes. Fill them with color-indicating sillica beads.

I change my desiccant weekly- or when the color changes from orange to green. Then revive the old sillica by putting it in the oven for 1 hour at low temp.

Printing Tips:

Use PLA or PETG for durability.
Adjust layer height to 0.2 mm for optimal strength.
Ensure good adhesion with a heated bed at 60°C.
2 walls, 15 % infill and NO support needed.
Print times:
25mm box : 1hr 11 minutes
40mm box: 1 hr 29 minutes.

Needed for Assembly:

- 4 pieces of 5x2 round magnets (for the lid)
- 8 pieces of 6x3 round magnets (for the base)

- a piece of double sided tape to attach the base.

- Drying agent (sillica will do just fine).

Assembly:
- Install 2 magnets (side 5x2) in the lid
- Install 2 magnets (side 5x2) in the upper part of the box that supports the lid
- Install 4 magets (size 6x3) in the base of the box
- Install 4 magets (size 6x3) in the base plate
- Attach the baseplate in your CFS, with the sloped edge down, so the box will stay upright at a 90 degree angle.

You might need to apply some pressure to press the magnets in (I used the back of a screwdriver),
If you want, add a drop of glue, but for me it was not needed.

Dryboxes for CFS (25 / 40 / 75 mm version)

75mm DryBox

40 mm DryBox

25mm DryBox