Cereal box dry filament storage

3D-Printed Spool Holder for Airtight Filament Storage

This is a 3D-printable spool holder designed to fit inside airtight cereal containers, specifcally designed for the Skroam (€25 - €30 for 6) / Wildone  (€50 - €55 for 6 ) (identical) cereal boxes available on Amazon. These containers provide a simple, cost efficient way to store filament while keeping it dry. By keeping the original lid, the container can be reused later if needed. 

The spool remains inside the airtight container while printing, rolling smoothly on 608ZZ bearings. This setup works well with Bambu Lab spools and likely supports other standard spool sizes.

3D-Printed Parts

The setup consists of five 3D-printed parts, with two being optional:

1. Base – Holds the spool and silica beads.
2. Base Lid – Covers the silica beads compartment.
3. Label – Indicates the filament type for easy identification.
4. Replacement Lid (optional) – Replaces the container’s original lid.
5. Tube Cap (optional) – Seals the filament tube airtight.

I print Parts 1,2 and 4 in PLA, but PETG, ABS, or other materials can also be used.
For the label (Part 3), I use the same filament as the spool for easy recognition.

For the tube cap (Part 5), TPU for AMS is recommended.
I found that printing with tree support (using the “touching the build plate only” setting) works fine.

When printing in PLA with PETG support interfaces, detailed instructions can be found here. 

https://forum.bambulab.com/t/support-filament-petg-for-pla-and-pla-for-petg-and-more/5942/4

Additional Components to buy

Required Components (for basic functionality):

• PLA, PETG, or ABS filament (~€22.99/kg)
• 1x Airtight Cereal Container (~€5.00 when buying Skroam)
• 1kg Silica Gel Beads (~€14.00, enough for 30 containers) → €0.50 per unit
• 4x 608ZZ Bearings (~€4.00 for 10) → €1.60 per unit
• 1x Mini Round Hygrometer (~€6.00 for 4) → €1.50 each

🛠️ Total cost per unit: ~ €10 .

Optional Components to buy (for improved usability):

• TPU for AMS Filament (~€27.99/kg) – For the airtight tube cap.
• 1x PTFE Tube (4mm OD / 2mm ID, ~1.50/m) → €0.15 per unit
• 1x PC4-M10 Pneumatic Fitting (~€4.00 for 10) → €0.40 each

Assembly Guide

1. Install the Bearings: Press 608ZZ bearings into the base (may require some force). Use a flat surface for support, I use the edge/corner of the table for that, works great!
2. Insert the Hygrometer: Place it in the designated slot in the base.
3. Attach the Filament Label: Snaps onto the base above the hygrometer.
4. Put on the Base Lid but leave a 25mm / 1 inch gap for filling the compartment with silica beads.
5. Fill with Silica Gel: Add ~50ml (~⅕ cup) of silica beads to the compartment. Shake the base slightly whilst filling to for even distribution of the silica beads in the base.
   • 🔹 Tip: Regenerate silica beads by microwaving briefly (avoid overheating).
6. Attach the Pneumatic Fitting: Mount PC4-M10 on the lid for airtight filament feed.
7. Install the PTFE Tube: Insert it into the PC4-M10 fitting, use TPU tube cap to keep it airtight when not in use.
8. Replace the Container Lid (Optional)
9. Final Assembly: Place everything inside the cereal container.

Conclusion

This cost-effective, non-destructive, and airtight spool holder keeps filament dry and prevents moisture issues. It is compatible with Bambu Lab AMS and other standard spools.

🚀 If you found this useful, consider leaving a like! 😊

I really like it if you could post a picture of your succesfull 3D print in the comments!


UPDATE:
The hygrometers that I used, I bought on Aliexpress from the seller “Shop1104001366 Store” . The original design has the notches placed at an angle (roughly at 1 o'clock and 7 o'clock), the new version also supports versions of the hygrometer / thermometer with the notches at 6 o'clock  and 12 o'clock.

The latter is available from the Bambu Lab store:

Circular Embedded Electronic Digital Thermometer Hygrometer
Model: B-XF001

I have now created an update for the base that accommodates both versions of the round hygrometer. You can download now the updated 3mf file via the “download stl/cad file”. The filename of the updated base is “Base-also-for-BambuLab-Hygrometer.3mf”