Sunlu AMS Heater - Intelligent Drying System for Multi-Material Module

The AMS Heater marks a turning point in 3D printing by offering a comprehensive simultaneous drying and printing solution, specially designed by SUNLU to optimize Automatic Material System (AMS) setups compatible with Bambu Labs FDM printers. This component, compatible with the first generation of AMS, keeps filaments in optimal condition without interruptions thanks to its innovative smart heating system, which reaches 70 °C in just 20 minutes, ensuring a uniform and controlled temperature throughout the printing process.

Video 1: Introduction to the SUNLU AMS Heater.

One of the main challenges in 3D printing remains the moisture absorption by filaments, which causes warping, poor layer adhesion, and print failures. With the AMS Heater, a definitive solution is introduced: the filament stays dry and stable while printing, eliminating the need for external pre-drying and significantly reducing preparation time.

Photo 1: The traditional printing method involved first drying the filament in an external module and then using it in the printer. Source: SUNLU

Photo 2: The AMS Heater enables simultaneous drying and printing, representing a major improvement. Source: SUNLU

Unlike the traditional workflow, which requires long drying times before using AMS, the AMS Heater allows you to print while drying the filament, with no quality loss. Comparative tests have shown that the quality of filament pre-dried for eight hours is identical to that obtained with real-time drying using the AMS Heater, saving up to 8 hours per spool.

Photo 3: Comparison of results using PA6-CF filament: (1) PA6-CF spools dried for 8 hours before loading into the AMS. (2) PA6-CF spools used directly after upgrading the AMS Heater, enabling edge drying while printing. As shown, both methods produce equivalent print quality, but the second saves 8 hours by combining drying and printing simultaneously. Source: SUNLU

Efficient heat, uniform distribution, and zero warping

Thanks to its dual air duct design, heat is distributed evenly, preventing localized overheating that can cause warping in sensitive materials like PLA, PETG, ABS, or Nylon. This thermal efficiency is combined with an insulating system that protects the AMS's internal electronics, preventing heat from affecting them and thus extending the system’s lifespan.

Photo 4: The AMS Heater delivers fast, uniform drying. Thanks to its dual air duct system, it reaches 70 °C in just 20 minutes and distributes heat evenly. This prevents hot spots and reduces the risk of material deformation. Source: SUNLU

Photo 5: The AMS Heater is designed to keep the hot airflow away from the AMS base electronics. Source: SUNLU

Multicolor expansion: more space, more possibilities

Another major improvement with the AMS Heater is its structural redesign. Unlike the original AMS's semicircular top cover, which limited stacking and hindered multi-color use, the AMS Heater supports a fully stackable configuration with up to 16-color printing, maximizing space and enabling multicolor printing without compromising functionality or stability.

Photo 6: In the first generation AMS, the semicircular lid prevented stacking when using more than 8 colors, wasting space. With the upgraded AMS Heater, units can now be stacked, enabling up to 16-color printing and optimizing available space. Source: SUNLU

Full compatibility and easy upgrade

The AMS Heater integrates perfectly with the original first-generation AMS structure, including precise alignment with the original sealing strips to maintain airtightness and prevent heat or humidity loss. Installation is quick and easy: in just two minutes, you can remove the old lid, attach the new component, and get started.

Photo 7: Installing the Heater on the first-generation AMS lid ensures perfect integration with the original sealing strip, maintaining sealing and energy-saving functions without losing compatibility. Source: SUNLU

Smart humidity control: rH Mode

The AMS Heater doesn’t just dry with heat—it also dries smartly. Its automatic humidity control system, known as rH Mode, maintains internal humidity levels between 25% and 50%, fully adjustable according to filament type. The default operating temperature in this mode is 55 °C, but it can be customized and saved.

Photo 8: In humidity mode (rH mode), the default temperature is 55 °C (adjustable), it runs for 6 h and automatically regulates humidity between 25% and 50%, restarting heating when exceeding the set threshold. Source: SUNLU

Additionally, this mode operates under a continuous logic: when the timer runs out, the device doesn’t shut off immediately. Instead, it monitors humidity levels in real time and automatically restarts heating if it detects the value exceeding the preset threshold. This ensures that filaments stay stable even when not in immediate use.

Advanced safety: triple integrated protection

In terms of safety, the AMS Heater includes a software-based temperature control system with multiple protection layers:

• Real-time monitoring.
• Automatic alarms if the temperature threshold is exceeded.
• Failure detection in fan or heating element.
• Auto shutoff after the programmed cycle ends.
• Thanks to its PTC heating technology, it self-regulates power based on internal conditions, reducing risk and improving energy efficiency.

Photo 9: PTC heating works in three stages: 1) During initial heating, resistance is low, allowing rapid heat-up thanks to high power (P = U²/R). 2) Once the target temperature is reached, resistance increases, reducing power and stabilizing heat. 3) In case of abnormal overheating, resistance becomes virtually infinite, automatically cutting off heating for safety.

Why the AMS Heater is essential for 3D printing

The evolution of the 3D printing market highlights a growing need for automated solutions to keep filaments dry, prevent warping, and achieve precise multicolor printing. The AMS Heater meets these demands by offering a unique combination of smart drying, structural compatibility, multicolor support, automated humidity control, and advanced thermal protection.

Ideal for professional users, demanding creators, and advanced manufacturing environments, the AMS Heater isn’t just an upgrade—it’s the new standard in 3D printing efficiency, control, and quality.

Video 2: A user reviews the AMS Heater, calling it “The best upgrade for your Bambu Lab AMS.”