SUNLU used its 13th-anniversary announcements to unveil the AMS Lite Heater, a $129.99 upgrade kit that adds active drying and humidity monitoring to Bambu Lab's AMS Lite multi-material system — and, notably, does it while a print is actively running rather than requiring a separate pre-drying step.
The pitch is straightforward: hygroscopic filaments like PLA, PETG, and nylon absorb ambient moisture over time, and moisture in filament during extrusion is a well-documented cause of stringing, popping, poor layer adhesion, and surface defects. Most fixes to that problem live outside the printer entirely — a filament dryer box the spool sits in before loading, run for several hours ahead of a job. SUNLU's approach instead treats drying as something that happens continuously, inside the AMS Lite housing, in parallel with the print itself.
What the Hardware Actually Does
According to SUNLU's July 1 press release, the AMS Lite Heater sustains temperatures up to 70°C and is rated for PLA, PETG, ABS, ASA, PA (nylon), and PC — a spread that covers both the easy, low-temperature consumer filaments and the more moisture-sensitive engineering materials where drying matters most. The unit also includes precision humidity monitoring with adjustable thresholds, letting users set the point at which the system should intervene rather than running the heater constantly regardless of actual conditions.
The press release also details a dual-airflow channel design intended to distribute heat uniformly through the chamber rather than concentrating it near a single vent, along with an automatic venting system meant to carry moisture out as it's driven off the filament. SUNLU pairs those with what it describes as multiple integrated safety protections and continuous temperature monitoring — the kind of guardrails that matter more once a heater is running unattended, inside an enclosure, for the duration of a multi-hour print rather than under supervision on a countertop.
Critically, SUNLU frames the design as additive rather than disruptive: the drying and monitoring functions are built to run simultaneously with printing without disabling any of the AMS Lite's existing multi-material handling. For anyone who has weighed the tradeoff between drying filament properly and keeping a multi-color or multi-material job moving, that's the core value proposition — you're not choosing between "dry filament" and "AMS Lite works normally."
Part of a Bigger Anniversary Push
The heater isn't launching in isolation. Per coverage from All3DP, SUNLU is bundling the announcement with a 10,000-roll global filament giveaway and an expansion of its US factory infrastructure intended to shorten delivery times for American customers. The giveaway itself is structured as a fixed set of prizes — 100 winners selected across multiple platforms will split the 10,000 rolls of filament, alongside 100 additional exclusive anniversary gifts and units of the AMS Lite Heater itself, timed to mark SUNLU's 13 years since founding in 2013. Retail launch for the AMS Lite Heater is set for July 20, 2026 at 07:00 UTC — just under three weeks after the initial unveiling, giving the company a short lead-in window before units actually ship to buyers.
The factory expansion detail is worth noting separately from the product itself: a third-party filament and accessory maker investing in US-based manufacturing and logistics capacity signals a bet that demand from the Bambu Lab ecosystem — and the broader third-party accessory market that has grown up around it — is durable enough to justify localized infrastructure rather than relying solely on cross-border shipping.
What It Means for Makers
For anyone running an AMS Lite, the appeal here is convenience rather than novel capability — drying filament before or during a print isn't new, but doing it inside the AMS unit itself, concurrently, without pulling spools out to a separate dryer box, removes a manual step from the workflow. At $129.99, the AMS Lite Heater positions itself as an accessory-tier purchase rather than a full drying-system investment, which matters for makers who already own an AMS Lite and are looking to extend its usefulness rather than replace their humidity-control setup outright.
The material coverage is the other detail worth weighing before buying. A 70°C ceiling and support for PLA, PETG, ABS, ASA, PA, and PC covers the filaments most commonly loaded into an AMS-style system for multi-material and multi-color work. Users running materials outside that list, or filaments that call for drying temperatures above 70°C, would need to check compatibility before assuming the heater covers their use case — the SUNLU release doesn't claim broader coverage than that six-material list.
The adjustable humidity thresholds also give some control over how aggressively the system intervenes, rather than a fixed always-on cycle — useful for makers who don't want a heater running full-time on filament that's already dry, or who want tighter drying for a nylon spool that's been sitting open longer than it should have. The dual-airflow design and automatic venting SUNLU describes are the mechanisms meant to make that intervention consistent across the chamber rather than uneven from one spool position to another.
None of this changes the underlying physics of moisture absorption or extrusion — a heater bolted to an AMS unit doesn't make filament immune to humidity, it just automates the mitigation. But automating a step that's historically manual, easy to skip, and directly tied to print-quality failures is exactly the kind of accessory that tends to get adopted quietly and then become assumed infrastructure. Whether SUNLU's implementation holds up under real-world, multi-day AMS Lite use — thermal consistency, actual moisture reduction, and whether "simultaneous with printing" holds true across long multi-material jobs — will be for buyers and independent testers to confirm once units ship on July 20.
For now, the announcement gives makers a concrete date and price to plan around, alongside a broader signal from SUNLU that it's investing in US-facing infrastructure at the same time it's expanding its accessory lineup for the Bambu Lab ecosystem specifically — a notable bet on a platform it doesn't manufacture itself.
