A passive drybox designed for direct printing — filament is loaded inside and fed directly to the printer without ever opening the box. No more unpacking spools every time you want to print.
The boxes are fully stackable, saving valuable workshop space. Each box features a silica gel compartment to absorb moisture, a port for a hygrometer to monitor humidity, and two rollers on bearings for smooth and effortless spool unwinding.
Built from PETG for rigidity with FLEX seals for an airtight fit. Print time is around 81 hours total — a significant investment that pays off in convenience and filament quality.
Download STL files from Printables. Print the main body and structural parts in PETG, seals and flexible parts in FLEX.
Print settings: Layer height 0.2 mm · 4 perimeters · 30% infill · No supports
Filament consumption: ~1.9 kg / 620 m
Total print time: ~81 hours
Prepare the following hardware before assembly:
· DIN 912 M3×8 — 8 pcs
· DIN 912 M3×10 — 36 pcs
· DIN 934 M3 nut — 44 pcs
· ISO 2338 5×32 pin — 6 pcs
· ZKL 608-2Z bearing — 4 pcs
· Grommet for PTFE tube 4×3-M5 — 2 pcs
Press the ZKL 608-2Z bearings into the roller housings. Insert the ISO 2338 5×32 pins as axles. The rollers allow the spool to spin freely with minimal resistance for smooth filament feeding.
Press the PTFE tube grommets (4×3-M5) into the outlet holes on the side of the box. Thread your PTFE tube through them to route filament directly to the printer while keeping the box sealed.
Fill the silica gel compartment with desiccant beads. Insert a small hygrometer into the dedicated port to monitor humidity inside the box. Regenerate the silica gel periodically in an oven.
Place your filament spool onto the bearing rollers, thread the filament through the PTFE grommet, and close the lid with the FLEX seal seated properly. Stack additional dryboxes on top as needed.
Designing the hinges was one of the bigger challenges. The lid is heavy, and hinges on a printed part need to be sized and oriented carefully. Underestimate the load and they crack after a few opens.
With over 40 bolts and nuts in the assembly, even small dimensional errors add up. Calibrating the printer before starting and using 4 perimeters ensured everything fit together cleanly.
Structural parts need to be oriented so layer lines run parallel to the main stress direction. Getting this right the first time saves reprinting parts that snap along layer boundaries.
This was only my second larger 3D printing project and genuinely a challenge. But the drybox does exactly what it was designed to do — filament stays dry, stacking works perfectly, and printing directly from the box is a real quality-of-life improvement.