filament dry Box with rotating rollers

This 3‑D printable insert converts a GoMaihe 4 L airtight food‑storage container into a sealed, low‑humidity filament feeder. Four rollers on 608 bearings (8 × 22 × 7 mm) support one spool up to 70 mm wide (≈1 kg, Ø200 mm), letting it turn freely while the lid stays closed. A press‑fit ring in the lid takes a round hygrometer/thermometer (Ø45 mm) so you can monitor temperature and humidity without drilling.

Key Benefits

• Consistently dry printing – The factory gasket plus a desiccant bay beneath the rollers hold relative humidity below 20 % RH, protecting hygroscopic materials such as PA, TPU and PVA.
• Smooth, low‑friction feed – Four 608‑bearing rollers centre the spool and let it rotate with minimal resistance, preventing tension spikes and tangles.
• Tool‑free monitoring – The snap‑in hygrometer ring adds environmental sensing with no glue, screws or drilling.
• Integrated filament pass‑through – A Ø4 mm PTFE‑tube channel preserves the airtight seal while guiding filament directly to the printer.
• Drop‑in installation – All parts fit the stock GoMaihe box; no cutting, drilling or adhesive required.
• Zero power draw – Maintains filament quality passively, unlike electric dryers.
• Compact footprint – Occupies only the space of the container itself, ideal for multi‑material setups or small workbenches.

Quick Assembly

1. Press 608 bearings into the four printed rollers.
2. Snap the rollers onto the base pins.
3. Prepare silica‑gel desiccant.
4. Pour about 40 g of granulate into each of the two desiccant cups located beneath the rollers.
5. Press the hygrometer into the lid ring and verify the seal.

Tip: Regenerate or replace the desiccant whenever humidity exceeds 20 % RH to keep your filament reliably dry.