How to Build a Heated Dry Box for Your Filament

Moisture is the enemy of good prints. Here's how to build a heated dry box that keeps your filament at optimal humidity while you print.

Parts needed

• Airtight food container (IKEA 365+ works great)
• PTFE tube fittings (4mm OD)
• Silica gel packets
• Hygrometer ($5 on Amazon)
• 12V PTC heater element (optional, for active drying)

Build steps

1. Drill holes for PTFE fittings on the lid
2. Install the PTFE tubes so filament feeds smoothly
3. Add silica gel and a hygrometer
4. For active drying, mount the PTC heater with a thermostat set to 45°C

The passive version (silica gel only) works great for PLA and PETG. For nylon and polycarbonate, the active heating version is worth the extra effort.