YOOPAI Filament Dryer Box S4

Solid drier. I print a lot of filament and a single spool dryer just wasn't going to cut it for my needs. This 4 spool dryer works well and does exactly what i need. I really like that it has outlets for using as a dry and print box. I print directly from this dryer on my bed slingers and the quality had really improved printing from a dry roll. Keeping your filament dry is keep to reducing stringing and having it stay within the box helps reduce tangles. The dryer has a solid amount of preset choices for temperatures for a variety of filaments, but you can fine tune it for any specialty filament. My only wish would be that it was split and could dry 2 types of filament at the same time. However I just throw them in as a little extra temperature doesn't appear to affect my PLA when drying with PETG.

The SUNLU S4 Filament Dryer Box is absolutely flawless. It arrived exactly as described and works perfectly right out of the box. The ability to dry four spools at once is a huge time saver, and the results are consistent—no more moisture issues or printing problems. The build quality feels solid, the controls are intuitive, and the temperature holds steady throughout the cycle. I’ve run multiple types of filament through it (PLA, PETG) and every spool came out dry and ready to print with noticeably improved performance. This product does exactly what it promises, and it does it reliably. For anyone serious about 3D printing, this is a must‑have accessory.

This SUNLU S4 filament dryer absolutely works like a champ. It heats up quickly, maintains a stable temperature, and the automatic humidity control is a great feature that I didn’t realize I needed until I had it. I love that it can handle four spools at once—super convenient for anyone who prints often or rotates between materials. The upgraded fans circulate air evenly, and I’ve already noticed a big improvement in print quality with moisture-sensitive filaments like PETG and TPU. The whole unit feels well-built and easy to operate. If you want a reliable, efficient filament dryer that just works, this is a great pick.

I have used this dryer with one roll, 2, 3 and 4 rolls at a time. Performs as expected each time. I have dried pla, petg, and abs. Make sure your spool is also rated for the drying temperature of the filament.

Filament was constantly breaking in my A1 until I got this dryer. Love the continous dehumidifier setting.