SUNLU Filament Dryer Box S1 Plus — Black 1.75/2.85/3.00mm, LCD, Adjustable 35–55°C

The SUNLU Filament Dryer Box S1 Plus is a compact, fan-assisted drying chamber that removes moisture from 1.75mm, 2.85mm and 3.00mm filaments and stabilizes printing performance.

The S1 Plus is SUNLU's 2026 black upgrade designed to reduce stringing, nozzle clogs and poor layer adhesion by drying and storing filament at controlled temperature, time and humidity. A clear 2-inch LCD shows live temperature, time and humidity; onboard controls let you tune the drying cycle to match PLA, PETG, ABS, TPU, Nylon or other materials. The unit's fan accelerates moisture removal while a roomy interior fits most full-size spools and smaller spools up to 210 x 89 mm (H).

How does the S1 Plus remove moisture from my filament?

The S1 Plus combines adjustable heating with active airflow to speed up water evaporation from filament surfaces and interior. The fan pushes warm, dry air across the spool so moisture exits more quickly than with passive storage alone.

• Adjustable temperature range from 35°C to 55°C for different materials.
• Built-in fan improves air circulation and reduces drying time.
• Digital humidity readout shows current environment inside the box.
• Timed drying cycles let you run longer sessions for hygroscopic filaments.

What filaments and spool sizes will fit in the box?

The chamber accommodates most common 1.75 mm, 2.85 mm and 3.00 mm filaments and fits a wide variety of spool diameters and widths up to the stated maximum. That makes it compatible with PLA, PETG, ABS, TPU, Nylon (PA) and other popular materials from major brands.

• Maximum internal dimensions 210 mm diameter by 89 mm height (H).
• Accepts standard and many larger spools within those size limits.
• Supports both 1.75 mm and 2.85/3.00 mm filament diameters.
• Works with PLA, PETG, ABS, TPU, Nylon and similar 3D printing filaments.

How do I control temperature, time and monitor humidity?

The S1 Plus uses an easy-to-read 2-inch LCD that displays temperature, remaining drying time and humidity percentage. Adjustments are simple: hold the left button to change drying time; press the right button to change temperature. The screen provides immediate feedback so you can tailor settings to each filament type and local environment.

• 2" LCD shows temperature, time left and humidity value simultaneously.
• Left button long-press changes the drying duration.
• Right button changes the target temperature (35°C–55°C).
• Real-time humidity readout helps confirm dryness progress.

Will using the S1 Plus improve my print quality?

Drying filament reduces moisture-related printing problems such as bubbling, stringing, uneven extrusion and weak layer adhesion. While results depend on material and printer settings, consistently dried filament generally yields smoother surfaces and more reliable extrusion during long or detailed prints.

• Reduces stringing and nozzle clogging caused by trapped moisture.
• Helps maintain consistent extrusion for better surface finish.
• Adjustable cycles let you optimize drying for hygroscopic materials.
• Fan-assisted airflow shortens drying time compared with passive boxes.

Who is this for? The SUNLU S1 Plus is aimed at hobbyists, prosumers and small workshop users who print regularly and want a simple, adjustable way to protect filament from humidity. It's particularly useful for users of hygroscopic materials (Nylon, TPU) or anyone experiencing stringing, poor adhesion or inconsistent extrusion after filament storage. If you need a compact, user-friendly filament dryer with clear feedback and broad filament compatibility, the S1 Plus is built to fit into most desktop 3D printing workflows.