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The Best Filament for the Bambu Lab AMS

Published: 2024-03-10

The Bambu Lab Automatic Material System (AMS) is one of the most compelling features of Bambu 3D printers. It allows you to print models with up to four different colors, and also lets you easily choose from any of your loaded filament types for a single-color print. Overall, it’s an accessory we highly recommend for Bambu owners.

However, one downside to the AMS is that it is a bit more picky with filament. Because of the way the AMS loads and retract filament spools, and the fact that it is an enclosed box, it’s not compatible with all filament types and brands. This can make it challenging to pick the right filament for use in your AMS. In this article, we’ll help you choose the best filament for the Bambu AMS, based on our own experience testing a variety of brands and materials.

Note: This article applies to the original Bambu Lab AMS, which is compatible with the Bambu P1P, P1S, X1C, and X1E 3D printers. Our recommendations in this article are likely to be a safe choice for the AMS Lite used on Bambu’s other 3D printers, but we haven’t tested with that unit.

We’ll start with an explanation of why the AMS doesn’t work with every filament brand, but if you’d prefer, you can jump straight to the recommendations.

Why Doesn’t All Filament Work?

Before we give our specific brand recommendations, we’ll briefly explain what you need to consider when choosing filament for the AMS and why some filament brands and types don’t work properly.

Filament Spool Design

The size and shape of the filament spool, as well as the material the spool is made of, affect how well the AMS can load and retract filament. This is because the AMS uses motorized rollers to spin the spool as the filament moves into or out of the 3D printer. It’s especially important when one of the spools is fully retracted during a color change, because it ensures the retracted filament wraps back around the spool instead of sitting loosely inside the AMS.

If the spool isn’t a standard-size 1kg spool, it won’t fit in the AMS bay and the rollers won’t be able to spin it. This means you can’t use larger 3kg or 5kg spools in the AMS, and may run into trouble with the smaller spools that some specialty filament types use.

Many users have also had trouble with spools that are made of cardboard rather than plastic. This is becoming more and more common among filament brands, especially at lower price points. In some cases, the cardboard spools can bind up and not spin smoothly, which prevents the AMS from loading or retracting the filament and causes an error.

Cardboard spools can bind up in the AMS, especially if the edges are bent or frayed.

There are a few solutions for using filament from incompatible spoons in the Bambu AMS:

For the cardboard spools, you can 3D print plastic rings which press-fit onto the edges of the spool. In some cases, this can help the spool spin more easily on the rollers, although we’ve occasionally had issues where these make the spool diameter too large, which can cause it to jam as it touches the lid of the AMS.
You can also transfer the filament onto a standard-size plastic spool, and the AMS actually includes four empty filament spools for this purpose. There are several designs online for 3D-printable spool winders, which allow you to transfer an entire spool of filament onto one of these plastic spools in only a few minutes. This is a good option for filament that comes in non-standard spool sizes, or for cardboard spools where the plastic rings do not work.

Material Type

Although most 3D printing filament types work in the AMS, flexible filament such as TPU does not work reliably. This is because the AMS has to push and pull the filamen through a long series of Bowden tubes and connectors to reach the printer’s extruder, and flexible filament typically does not behave well when it’s pushed through a long tube. You may be able to get TPU to feed in some cases, but it’s not reliable and therefore we don’t recommend it in the AMS.

Instead, if you want to 3D print with TPU while you have the AMS unit connected to your Bambu printer, we recommend you 3D print a Bowden tube splitter (or buy this purpose-built part from the Bambu Lab store) and feed the TPU spool from a standard spool holder.

All other standard material types should work in the AMS, although you may run into issues with especially old filament. As filament gets older, it can become brittle, and can break as the AMS pushes it through its internal tubing. It’s not hard to fix this, but it will cause the print to fail or stop with an error.

Recommended Filament for the AMS

Based on our testing, we have a few specific recommendations for filament brands that we’ve found to work well in the Bambu Lab AMS. We think these are a good starting point if you’re buying filament to use in the AMS.

Some of our favorite filament choices for the AMS. Left to right: Bambu, Hatchbox, Sunlu, Overture. All are PLA.

Bambu Lab Filament

Bambu Lab has it’s own brand of filament, and as you might imagine, their filament is known to work well in the AMS. It’s not the only filament brand we recommend, and most of our own AMS use has actually been with other brands, but it’s a great choice for use in the AMS.

Bambu Lab’s filament spools include an RFID tag which the AMS reads when you insert the spool into the unit. This allows the AMS to automatically configure the color, filament type, and settings for that material, saving you a few manual steps when you load a new spool. Without the RFID tag, you have to configure these settings either in the Bambu computer or smartphone app, or on the display of the Bambu X1C or X1E. The settings aren’t hard to configure, but it’s easier to have the printer set them automatically.

Bambu filament spools contain an RFID tag that allows the AMS to automatically configure the color and material.

Of course, the Bambu filament spools are also the right size and shape to load and retract properly in the AMS, so they will work reliably in that regard.

Bambu sells a wide range of filament types and colors, including PLA, PETG, ABS, PA, and carbon fiber-based filament. Within each of these material types, they have some interesting colors, including “silk” varieties, gradients, and sparkly colors. They do also sell TPU, but even Bambu’s TPU is not recommended for use in the AMS.

The main problems with Bambu’s filament are its price and availability. Their filament is a bit more expensive than some of the other options, although it’s cheaper if you purchase their “filament membership” or buy a refill spool instead of a normal spool. They are also often sold out of some of their colors, so you may need to keep an eye out for a specific color to be in stock.

Regardless, Bambu’s filament is a great option for the AMS.

You can view the filament selection on Bambu Lab’s online store.

Other Recommended Filament Brands

We’ve had good success with several other filament brands in the AMS, and many of them are more affordable than Bambu’s filament and available for fast shipping on Amazon or other sites.

Specifically, we’ve had good luck with the following:

MatterHackers Build Series PLA and PETG: We’ve had great success with this filament in the AMS. It’s more affordable if you purchase multiple spools at once, as well.
Hatchbox PLA and ABS (Amazon): Hatchbox has long been one of our top recommended filament brands, especially for high-detail PLA prints. It’s also the only brand we recommend for ABS due to its resistance to warping compared to other filament brands.
Sunlu PLA (Amazon): Sunlu is one of the few affordable filament brands that still uses plastic spools, making it well-suited for use in the AMS. We’ve liked the quality and colors of Sunlu’s filament, as well.

You can 3D print plastic rings that press-fit onto cardboard spools, which may improve reliability.

We’ve also had success with Overture PLA (Amazon), but Overture uses cardboard spools that have caused problems for some users. In particular, if the edges of the cardboard become bent or frayed, the spool can jam in the AMS. As we discussed above, you can 3D print plastic rings to reinforce the edges of the spool, or print a respooler to transfer the filament to a reusable plastic spool. However, with that said, we’ve generally been able to use Overture spools in our AMS with no modifications.

As a last note, these are only the filament brands we’ve tested thoroughly and can confirm are good choices for use in the AMS. There are likely several other brands that also work well—if you’ve tested one that we don’t mention here, send us a note. We’ll keep this page up to date as we hear from users and continue to do testing with more brands.