1. Introduction
The SUNLU S1 Plus Filament Dryer Box is an essential accessory for 3D printing enthusiasts and professionals. It is designed to effectively remove moisture from 3D printer filaments, which can significantly degrade print quality, leading to issues such as stringing, clogging, and poor layer adhesion. By maintaining optimal filament dryness, the S1 Plus ensures smoother surfaces, better print quality, and improved overall printing success.

Figure 1: SUNLU S1 Plus Filament Dryer Box
Video 1: Overview of the SUNLU Filament Dryer Box S1 Plus, demonstrating its features and benefits for 3D printing.
2. Product Features
- Fast Drying with Fan: Features an upgraded fan design for accelerated moisture discharge, reducing the impact of humidity on 3D printing.
- Visual Display: Equipped with a 2-inch LCD screen that accurately displays temperature, time, and humidity.
- Personalized Settings: Allows adjustment of drying temperature (35℃-55℃) and time (0-24 hours) to suit different filament types and environmental conditions.
- High Compatibility: Accommodates filament spools up to 210x89(H)mm, compatible with 1.75mm, 2.85mm, and 3.00mm PLA, PETG, ABS, TPU, Nylon, and PA filaments from various brands.

Figure 2: Illustration of the 360-degree hot-air circulation system for uniform heating and effective drying.

Figure 3: Visual comparison highlighting the benefits of dried filament, including smoother surfaces and better layer adhesion.
3. Setup Guide
3.1 Unboxing and Components
Upon opening the package, ensure all components are present:
- SUNLU S1 Plus Filament Dryer Box
- Power Adapter
- User Guide (this manual)

Figure 4: What's in the box.
3.2 Initial Setup
- Place the SUNLU S1 Plus on a stable, flat surface.
- Connect the power adapter to the dryer box and plug it into a power outlet.
- Open the transparent lid of the dryer box.
- Place your filament spool inside the dryer box. Ensure the filament unwinds smoothly.
- Close the lid securely.

Figure 5: Visual steps for turning on, loading filament, setting parameters, and starting printing.
4. Operating Instructions
4.1 Controls and Display
The S1 Plus features a 2-inch LCD screen and two control buttons for easy operation.

Figure 6: Function Diagram of the control panel.
4.2 Power On/Off and Mode Selection
- Power On: Hold the left button to power on the device. The LCD screen will light up, displaying the current temperature.
- Change Mode: Press the right button to cycle through display modes: Temperature (PV℃), Humidity (%RH), and Time (SV Time).
- Power Off: The device will automatically power off once the set drying time is complete. To manually turn off, unplug the power adapter.
4.3 Setting Temperature and Time
- Set Temperature: While in Temperature mode, press the left button to enter temperature setting. Use the left and right buttons to adjust the target temperature (SV℃) between 35℃ and 55℃.
- Set Time: While in Time mode, press the left button to enter time setting. Use the left and right buttons to adjust the drying duration (SV Time) from 0 to 24 hours.
- The device will automatically begin heating and drying once settings are confirmed.
Video 2: Demonstration of setting temperature and time on the SUNLU 3D Printer Filament Dryer S1 PLUS.
4.4 Filament Compatibility and Recommended Settings
The S1 Plus is compatible with various filament types. Refer to the table below for recommended drying temperatures and times:

Figure 7: Recommended Drying Temperature for Filaments.
| Material | Baking Temp (℃) | Time (Hours) |
|---|---|---|
| PLA, WOOD, PVB | 45-50 | 3-6 |
| ABS, HIPS, PC, PA | 50-55 | 3-6 |
| PETG, TPU | 47-51 | 3-6 |
Note: These are general recommendations. Optimal settings may vary based on filament brand, age, and ambient humidity.

Figure 8: High Compatibility with 99% of 3D Filament Spools.
5. Maintenance
Regular maintenance ensures the longevity and optimal performance of your SUNLU S1 Plus Filament Dryer Box.
5.1 Cleaning
- Before cleaning, ensure the device is unplugged and completely cooled down.
- Wipe the exterior and interior surfaces with a soft, dry cloth.
- Do not use abrasive cleaners or solvents, as they may damage the plastic.
- Ensure no liquids enter the electronic components.
5.2 Storage
- When not in use, store the dryer box in a cool, dry place away from direct sunlight.
- It is recommended to store filament in sealed bags with desiccant after drying to prevent re-absorption of moisture.
6. Troubleshooting
If you encounter issues with your 3D prints, consider the following common problems and solutions related to filament moisture:
- Stringing, Blobs, or Zits: These are common indicators of wet filament. Ensure your filament has been adequately dried using the recommended settings for its material type.
- Clogging or Extrusion Issues: Moisture can cause steam bubbles during extrusion, leading to clogs. Dry your filament thoroughly before printing.
- Poor Layer Adhesion: Wet filament can result in weaker layer bonds. Drying the filament can significantly improve print strength and adhesion.
- Noisy Operation: The S1 Plus is designed for low noise operation. If you experience unusual or excessive noise, ensure the unit is on a stable surface and there are no obstructions to the fan or filament spool.

Figure 9: Low Noise Operation for a peaceful printing environment.
7. Specifications
| Attribute | Detail |
|---|---|
| Brand | SUNLU |
| Model Number | SUNLU S1 PLUS Noir |
| Item Weight | 2.64 pounds (1.2 Kilograms) |
| Product Dimensions | 9.33 x 3.94 x 10.67 inches |
| Color | Black |
| Material Type | Polyethylene Terephthalate Glycol (Housing) |
| Number of Items | 1 |
| Compatible Filament Diameter | 1.75mm, 2.85mm, 3.00mm |
| Adjustable Temperature Range | 35℃-55℃ |
| Adjustable Drying Time | 0-24 hours |
8. Warranty and Support
SUNLU provides after-sales service and technical support for the S1 Plus Filament Dryer Box. If you have any questions, require assistance, or experience issues with your product, please do not hesitate to contact SUNLU customer service.
For support, please refer to the contact information provided on the official SUNLU website or through your purchase platform.





