If you own a Bambu Lab A1 or A1 Mini with an AMS Lite, there's one thing your printer has been missing since day one: a way to keep your filament dry while it's actually printing. Today we're checking out the Sunlu AMS Lite Heater, an upgrade designed to solve exactly that problem.
Do You Even Need a Filament Dryer?
If you're mostly printing in PLA, you may not need one. But once you start working with materials like PETG, nylon, or polycarbonate, a dryer stops being optional.
The AMS Lite Heater isn't a replacement for your AMS Lite — it's designed to work with it. Whether you have an A1 or an A1 Mini, anything that uses the AMS Lite can use this heater. Instead of swapping out your AMS system, the unit mounts around it with a few easy tweaks.
What Exactly Is the AMS Lite Heater?
At first glance, it looks like a protective enclosure for the AMS Lite. But it's more than that — it actively heats your filament while you're printing. That matters because it lets you draw filament and keep printing continuously, instead of pulling it out to dry in a separate dryer first.
The heater supports drying temperatures up to 70°C while maintaining all the original AMS Lite functionality. That means your filament stays in a controlled environment from the moment you load it to the moment you remove it after printing.
Why Moisture Is the Enemy
If you've been around 3D printing for a while, you've heard about wet filament. Many filaments naturally absorb moisture from the air, especially if left out — a property called hygroscopy. When moisture builds up, you get:
• Excessive stringing
• Rough surface finish
• Inconsistent extrusion
• Poor layer adhesion and weaker parts
Some materials barely absorb moisture at all — PLA is a good example, though this can vary depending on additives in the specific PLA. Other materials soak it up fast. That's why keeping filament dry becomes far more important once you move past PLA.
Material-by-Material Breakdown
The Sunlu AMS Lite Heater is designed to work across a wide range of filaments:
PLA — Probably the least of your concerns. It absorbs very little moisture, if any. If you're only printing basic PLA, this upgrade may not be essential, though heating PLA that's been sitting out can still help maintain consistency.
PETG — Absorbs moisture quickly, which is where a lot of stringing and print inconsistency comes from. Keeping PETG dry makes a noticeable difference in print quality.
ABS and ASA — Don't absorb moisture as aggressively as some engineering materials, but still benefit from a dry environment, especially after sitting around for a while.
Nylon — Absorbs moisture readily. If you've printed nylon before, you already know keeping it dry is essential — it's one of the main reasons products like this exist.
Polycarbonate (PC) — Benefits greatly from drying since it's often used for strong, functional parts. Lower moisture levels mean more consistent, reliable results.
According to Sunlu, the AMS Lite Heater supports drying PLA, PETG, ABS, ASA, PA (nylon), PC, TPU, and other common filament materials, with adjustable drying temperatures up to 70°C.
One important caveat: just because the heater can dry a material doesn't mean the AMS Lite or printer can feed it through the AMS. TPU, for example, isn't designed to run through the AMS on the A1 or A1 Mini — it needs to feed directly into the print head. And since the A1 and A1 Mini don't have a heated chamber, drying the filament won't guarantee perfect prints on its own. This upgrade is about keeping your materials dry in storage and during your workflow — it doesn't expand what the AMS Lite itself can handle.
Installation and Features
Installation involves a bit more than simply placing your AMS Lite into an enclosure. The AMS Lite mounts directly into the heater using the supplied hardware and adapter brackets, creating what feels like one integrated unit. Once assembled, your AMS Lite works exactly as it always has — you've just added active drying and humidity control around your filament.
Beyond heat, the unit packs in a few standout features:
• Dual-channel airflow to circulate warm air evenly through the chamber
• Automatic moisture venting that releases humid air during drying instead of trapping it inside
• Continuous humidity monitoring, with automatic drying activation when humidity rises above preset levels
• LCD display on the front for monitoring temperature and humidity, selecting filament type, adjusting drying temperature from 35°C to 70°C, and setting drying times
Putting It to the Test
To try it out, we hooked the heater up to a Bambu Lab A1 and printed a four-color dragon model (designed in-house — you can grab it at MakerBuildIt.com or MakerWorld) in PETG.
The dragon came out really nice after the PETG was properly dried. For comparison, we also printed one in PLA — it came out great too, arguably with even cleaner lines than the PLA print.
Should You Add It to Your Workflow?
If you tend to leave material loaded in your AMS for long periods, print regularly in PETG or other engineering materials, or just want a simpler overall workflow, the Sunlu AMS Lite Heater is worth considering.
Sunlu sent us this unit to evaluate, and they currently have it available at an introductory price. If you've been thinking about adding a filament dryer to your A1 or A1 Mini setup, that pricing makes it worth a look.
This is one of the more practical upgrades we've seen for the Bambu Lab A1 and A1 Mini workflow with the AMS Lite. It doesn't try to reinvent the system — it works with your current AMS Lite to create a controlled environment and a better overall workflow, especially if you're working with a variety of materials.
For more on 3D printing DIY maker projects, make sure you like and follow Maker Build It — and remember, keep on making. And remember: the best filament upgrades aren't always new materials. Sometimes it's just about keeping the materials you already have dry.
Learn More About the Sunlu AMS Lite Heater: https://store.sunlu.com/products/sunlu-ams-lite-heater-upgraded-your-bambu-lab-ams-lite
Download the Tiny Dragon STL: https://makerbuildit.com/products/tiny-four-color-dragon
Tiny Dragon STL on MakerWorld: https://makerworld.com/en/models/3033531-tiny-four-color-dragon
Disclosure: Sunlu provided this unit for evaluation.