Bambu Lab's Automatic Material System, or AMS, received a big upgrade with the release of the AMS 2 Pro in 2025. It's one of the best quality-of-life upgrades you can make to a Bambu Lab printer, but it's not without its flaws.
Here are some of the downsides I've noticed over the past couple of months, and a few things I'm hoping will get fixed in the next version.
You can't use flexible filament in an AMS
Not TPU for you
Bambu Lab
Thermoplastic polyurethane (TPU) is a flexible filament that comes in a variety of hardness levels. At its most flexible, TPU is springy, bouncy, and excellent at absorbing impacts. Flexible PLA is another example. These filaments can be difficult to print with as a result of their noodle-like behavior .
You can't just use any old flexible filament in an AMS unit. Thanks to its rubbery nature, strands of filament have a hard time making it through the PTFE tube that connects your AMS 2 Pro and your extruder. Flexible filament frequently folds on itself, jams, and is unworkable in a loader like this.
You can officially use one type of TPU in an AMS: Bambu Lab's own TPU for AMS . This filament is nowhere near as squishy as "real" TPU and might leave you disappointed. You'll have better luck with soft TPU if you attach it to your printer's side spool, but you're going to have to print very slowly and add an accessory like the TPU Feed Assist Module ($50) for best results.
A filament dryer with limitations
It's for PLA and PETG though
Tim Brookes / How-To Geek
One of the standout features of the AMS 2 Pro is its built-in filament dryer. 3D printing materials are hygroscopic, which means they absorb moisture from the air. So-called "wet" filament can be brittle and cause all sorts of printing issues from excessive stringing to failed prints.
Having an all-in-one dryer, loader, and storage system is a huge selling point. But you should know that the AMS 2 Pro only reaches a maximum temperature of 65ºC. This makes it perfect for drying PLA, PLA+, PETG, and TPU.
Some ABS and ASA filaments will work, though it's often recommended that they are dried at around 75ºC. Nylon (PA) requires temperatures of around 80ºC to dry, while some polycarbonate (PC) filaments call for as much as 100ºC to fully dry. The AMS 2 Pro can't reach these temperatures, so the purchase of a dedicated dryer like the AMS HT ($160) might be necessary.
Drying can be fiddly
It's more hands-on than the printer's other functions
Tim Brookes / How-To Geek
This is a small issue, but it's something I've run into. The best way to dry filament in an AMS is to rotate it slowly to enable even exposure to the fan. In order to do this, you have to unload the filament from the dryer, tuck it into the small holes on the spool (or use a compatible clip), and then initiate the drying process on the printer.
This is a little bit tedious, and the fact that drying can only be initiated on the printer means you can't trigger it using the mobile app. A few times I've planned to print something while out of the house, only to notice that the humidity inside the dryer has crept up and that I should probably dry my filament first. I then remember I can't do it remotely (for good reason, of course).
You also have to be a little careful that you don't let go of a tightly-wound spool and create a spaghetti monster in your AMS while doing this.
You'll need more silica gel
A few more sachets wouldn't have hurt
Patrick Campanale / How-To Geek
The AMS 2 Pro comes with two packets of indicating silica gel that sit in the back of the unit. This is nowhere near enough gel to keep your filament dry (at least not in my sub-tropical climate), which explains why silica gel holders are among the most popular prints for Bambu Lab printer owners who have an AMS.
Considering the price of the unit, it would have been nice to have some more desiccant in the box.
It's pretty expensive
You've got to spend money to "save" money
Tim Brookes / How-To Geek
The AMS 2 Pro costs $359 on its own, though you can save some money if you wait for a sale. By comparison, it only costs $250 if you buy in a combo pack at the same time as your printer. The new Bambu Lab X2D costs $649 on its own, or $899 with the AMS 2 Pro.
This is an age-old marketing tactic, but it still feels like quite a jump in price to purchase the AMS 2 Pro later. The "smart" thing to do is cough up the extra cash when you buy your printer (I know, that's exactly what Bambu Lab is thinking).
Even if you aren't interested in multi-color printing, having four (or more) spools loaded and ready to go makes life so much easier.
You'll probably want another one
The price of friction-free printing
Patrick Campanale / How-To Geek
Even if you bought your AMS 2 Pro in a combo with your printer, you might still be tempted to cough up more money for an additional unit, given how useful the system has proven to be. You can add up to four AMS 2 Pro units to a compatible Bambu Lab printers, for a total of 16 spools.
Some printers, like the H2 series, can also interface with eight AMS HT units at the same time (plus the external spool holder) for a total of 25 filaments.
The AMS 2 Pro has given me no issues and makes it easy to keep four filaments loaded and ready to print. This simplicity encapsulates the "plug and print" philosophy, which is why so many people are picking Bambu Lab printers .
