The X1 Carbon ships in two configurations that change how you load filament day to day. The standalone version feeds a single spool from the rear holder through a PTFE tube into the toolhead. The Combo version adds the AMS (Automatic Material System), a four-slot unit that sits on top of the printer and can feed any of four spools into the same toolhead, switching between them automatically during a print. Both routes end at the same hardened steel, all-metal hotend, rated to 320°C, so the loading mechanics differ but the melt zone does not.
This guide covers direct loading and unloading without the AMS, the full AMS workflow including RFID detection and mid-print color changes, how to move between the two feed paths, and what Bambu actually recommends for drying and storing filament on this printer. It also covers which materials the X1 Carbon’s enclosure and hotend genuinely support, since that list is longer than what an open-frame printer can handle.
Loading filament without AMS (spool holder)
This is the path for a standalone X1 Carbon, or for any filament the AMS does not handle well, such as TPU.
- Set the hotend temperature for the filament you are loading. Bambu’s own guidance uses roughly 220°C as a starting point for PLA; adjust for other materials.
- Wait for the hotend to reach that temperature before feeding anything in.
- Mount the spool on the rear spool holder and cut the filament tip to a 45 degree angle so it feeds cleanly.
- Feed the tip into the rear PTFE tube and push it through until it reaches the extruder.
- On the printer screen, open the filament tab, tap the rear spool holder icon to select it, then tap Load. When the prompt appears, push the filament in by hand to help it catch.
- Keep extruding until the old color or the purge stringing clears and the new filament runs clean.
Unloading filament without AMS
From the filament tab on the screen, select the loaded spool holder slot and tap Unload. The nozzle heats to the current filament’s temperature, retracts the tip out of the melt zone, and the process finishes on its own. Do not pull on the filament until the screen indicates it is done. Once it is clear of the extruder, you can pull the remaining length out of the PTFE tube by hand.
Loading a spool into the AMS
- Open the AMS cover and set the spool into an empty slot.
- Push the grey feeder tab in front of that slot and feed the filament in a couple of centimeters. The AMS detects the filament through a sensor at the feeder and pulls it in on its own, a process Bambu calls pre-loading. You can also tap the empty slot’s icon on the screen before inserting filament; this spins the feeder gears to help pull the tip in.
- Wait for the slot to finish pre-loading and, if RFID reading is enabled, reading the spool’s tag.
There is no separate "load" button to press for this first step. Pushing the filament into the feeder is what starts the process.
RFID detection and configuring filament information
Bambu’s own filament spools carry RFID tags on both sides, and the AMS has two reader boards that can read them. With official spools, the AMS identifies filament type and color automatically once the tag is read; you can tap a slot on screen to view that information, but you cannot edit it. Reading happens right after pre-loading, and can also be triggered on printer startup if you enable "Read Filament on Startup," or manually per slot with the Re-Read option.
Two things worth knowing about the RFID reader:
- It cannot read a slot while filament is currently fed out to the toolhead. If you tap Re-Read on a slot that is loaded into the extruder, the screen reports the AMS is busy.
- The same RFID pass is also how the AMS estimates remaining filament: it reads how much filament unspools per rotation of the tag past the sensor and calculates a rough percentage against a 1kg spool baseline. Treat that number as an estimate, not a precise weight reading.
Third-party spools without an RFID tag need their filament type, color, and temperature entered manually on the screen or in Bambu Studio the first time they are loaded into a slot. After that, the AMS remembers what was last configured for that slot until you change it. You cannot edit filament information while a print is running.
Unloading filament from the AMS
Tap Unload on the slot’s screen. This returns the filament from the extruder back into the AMS. Then push the feeder tab forward by hand and pull the spool’s filament out.
If the AMS rollers feel stuck when you try to pull filament out, usually after a power loss or an error mid-print, the drive gear may still be engaged with the spool. Push the spool gently toward the front of the AMS and then back again; this should disengage the gear so you can wind the remaining filament back onto the spool by hand.
Switching between the AMS and the rear spool holder
The AMS does not handle every filament well. TPU and some larger spools are meant to run from the rear spool holder instead, even on a Combo unit. On firmware from OTA 1.1.0.0 onward, switching between the two no longer requires unplugging any cable:
- If filament is currently loaded into the toolhead from an AMS slot, select that slot on the AMS page and tap Unload to return it to the AMS.
- Disconnect the PTFE tube from the printer side by pressing the plastic coupler release.
- Load the new filament from the rear spool holder using the steps above.
- When starting the print, uncheck "Enable AMS." With this unchecked, the printer pulls from the spool holder instead of any AMS slot.
Older firmware, before OTA 1.0.0.0, required powering off the printer and physically unplugging the 4-pin AMS connector near the spool holder before switching feed paths. If your printer is running an older version than that, update it before relying on the toggle above.
Changing color or material mid-print
When you send a multi-color model from Bambu Studio, the slicer automatically maps each color in the model to the closest matching filament currently loaded in the AMS slots, and you can reassign that mapping manually in the print dialog before sending the job. During the print itself, the AMS unloads the finishing color back partway and loads the next one into the toolhead without you doing anything, purging the transition through the same nozzle.
Filament runout works differently depending on setup. Printing a single material without the AMS, or with only one AMS slot in use, a runout pauses the print and asks you to load new filament. In multi-color prints, the AMS’s own troubleshooting documentation notes an edge case: if the last stretch of filament detaches from the spool while a color change is due, it cannot be pulled back, so the printer purges the remaining length and switches to the next slot once that purge finishes. Watch the screen in that situation, since it will say the old filament is being cleared rather than reporting a runout error outright.
There is also an AMS Auto-Refill option, off by default, in the AMS settings. Turn it on and the AMS will automatically switch to a different spool with the exact same brand, type, color, and nozzle temperature when the active one runs out, without pausing the print. If no matching spool is loaded elsewhere in the AMS, it falls back to reporting the slot as empty. Bambu’s own guidance is not to pause and manually unload a slot mid-print if you are relying on Auto-Refill, since unloading can interrupt the backup logic and cause the printer to pull from the rear spool holder instead.
Drying and storage
The stock AMS is a moisture-proof enclosure, not an active dryer. It ships with a humidity sensor and silicone O-ring seals to keep the internal air dry, plus color-changing desiccant packs you replace when they saturate. That keeps filament from absorbing new moisture while it sits loaded, but it will not remove moisture that is already in a spool.
Active drying on an X1/P1 series printer requires the AMS 2 Pro, a separate accessory with its own heating element, and it needs a dedicated switching power adapter since the printer itself cannot supply enough power for the drying module. With official Bambu filament, the AMS 2 Pro reads the RFID tag and sets drying temperature and time automatically; for anything else, you set both manually, with a maximum drying temperature of 65°C. That ceiling covers PLA, PETG, and similar materials comfortably, but Bambu’s own guidance points to the higher-capacity AMS HT for filaments that need hotter or longer drying than the AMS 2 Pro’s 65°C limit allows.
Without an AMS 2 Pro, Bambu’s documented alternatives are a forced-air convection oven, kept well clear of the heating elements to avoid uneven heat, or the printer’s own heated bed with an improvised lid, such as a filament box or a PC container, to hold the heat in. Bambu is specific that a microwave or a standard kitchen oven should not be used for this, since both heat unevenly enough to damage the spool or the filament itself. Whatever method you use, once a spool is dry, get it back into a sealed container with fresh desiccant or back into the AMS promptly, since it starts reabsorbing moisture as soon as it is exposed to open air again.
For the general principles behind all of this, independent of which drying hardware you own, see the site’s 3D Printer Filament Storage guide.
What the X1 Carbon can actually print
The enclosed chamber (Bambu specs it up to 60°C) and the all-metal hardened steel hotend (320°C max) are what separate the X1 Carbon’s material range from an open-frame printer like the A1 or A1 mini. Bambu’s own filament compatibility table lists ABS, ASA, PC, PA, and their carbon fiber or glass fiber reinforced variants (PA-CF, PAHT-CF, PC-CF, and similar) as filaments that specifically need an enclosed printer, the X1 Carbon included, to control warping and layer adhesion at their required print temperatures. PLA, PETG, TPU, and their reinforced variants print fine on this machine too, since none of them strictly require the enclosure, though PETG-CF benefits from it.
Not every one of those materials is a good match for the AMS itself, separate from whether the printer can print it. Bambu does not recommend feeding TPU or PET-CF/GF through the AMS at all, since these are either too soft or too abrasive for its feed channel long-term, even though the printer’s hotend handles both without issue when fed from the rear spool holder. Carbon fiber and glass fiber blends in general are harder on the AMS’s internal PTFE tubing than plain PLA or PETG, so if you print a lot of fiber-filled filament through the AMS, expect to replace that tubing sooner than on a printer running mostly PLA.
Related X1 Carbon guides
For the rest of the setup process, see Unboxing and Safe First Setup, the First Print Walkthrough, Bed Leveling and Calibration, and Bambu Studio Setup. If a filament load, unload, or AMS operation throws an error code, check the X1 Carbon HMS Error Index for what it means and how to clear it.