July 4, 2026
Bambu Lab AMS Explained: What It Is and Which Version You Need

AMS (Automatic Material System) is Bambu Lab's proprietary system for automatically swapping filament mid-print. It's what lets a printer produce multi-color models without a single manual pause to change spools.
How it works
AMS is a unit with several spool slots (usually four) that feeds the right filament into the printer on command from the slicer. The printer determines which color or material is needed at a given moment in the print, and the AMS switches the feed — no manual intervention needed, even if the model uses four or more colors.
AMS versions
| Model | What's different |
|---|---|
| AMS (base) | 4 slots, no drying, for standard P1/X1 printers |
| AMS Lite | simplified version for A1/A1 mini, open design |
| AMS 2 Pro | adds built-in filament drying — relevant for hygroscopic materials (nylon, PETG after long storage) |
| AMS HT (High Temperature) | built for engineering plastics with high print temperatures, for the H2 line |
What it's good for in practice
- Multi-color and multi-material printing without stopping the printer — a 4-color model prints as autonomously as a single-color one.
- AMS 2 Pro solves the storage problem for hygroscopic filaments (PETG, nylon) — it dries the material right before feeding it, no separate dryer needed.
- Multiple AMS units can be linked together, increasing the number of colors/materials available in a single print.
Limitations
- AMS only works within the Bambu Lab ecosystem — it's not a universal solution for any printer.
- Color changes aren't free in material terms: switching filaments purges some material as waste — factor that into material usage for multi-color models.
- AMS Lite (A1/A1 mini) has no drying — hygroscopic materials on these models still need a separate dryer.
How it affects cost
Multi-color printing through AMS saves the maker's time (no standing over the printer swapping spools by hand), but it doesn't save material — purging at every color change increases filament use per order, and that's worth accounting for as its own line item in cost calculations, not folding it into the model's general material usage.
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