Bambu Lab AMS — what it is and do you really need it?

The Automatic Material System: how it works, what it wastes, and who actually benefits.

2026-01-28 · 3DHub.ge

The AMS (Automatic Material System) is Bambu Lab's unit that holds four filament spools and swaps between them automatically during a print.

How it works

Four spools go into the AMS. The printer picks the one it needs, monitors humidity, and if a spool runs out mid-print it automatically switches to a backup.

Two very different benefits

1. Multi-colour printing. Up to four colours in one model — logos, colourful figures, lettering.

2. Automatic continuation. Often the more valuable one: you print a 20-hour part in a single colour, and if the spool runs out the printer simply continues from the next one instead of ruining the job.

The main downside — waste

Every colour change purges the old colour out of the nozzle. That purged material is the so-called "poop" — small waste blobs that pile up beside the printer.

The reality: on a small four-colour model the waste can weigh more than the model itself. Multi-colour printing also slows the job down considerably.

Is it worth it?

Yes, if: you print colourful models, toys or gifts; or you often run the printer overnight and do not want an empty spool to ruin a long job.

No, if: you mostly print single-colour functional parts. In that case, spend the money on a better printer or better materials instead.

Frequently asked questions

How many colours can the AMS print?

A single AMS holds four spools, so four colours. Chaining multiple AMS units increases that.

Does the AMS waste a lot of filament?

Yes, when printing in multiple colours — each colour change purges the nozzle. For single-colour printing there is no waste.