Bambu Lab printers support two ways of feeding filament: the AMS (for multi-color printing and automatic filament detection) and the rear spool holder (for filament types the AMS doesn't support, like TPU, or larger spools). Not sure which your filament needs? Bambu Lab's filament guide shows which materials are AMS-compatible. The steps differ slightly depending on which one you're using.
Loading Filament via the AMS
1. Open the AMS cover and insert the spool
Place your filament spool into an open slot. The AMS will detect the spool and begin the loading process automatically.
2. Feed the filament into the feeder
Gently push the grey tab in front of the feeder and push the filament in about 2 cm. The AMS will detect it and begin loading automatically. You'll feel some resistance from the tab — that's normal.
3. Confirm filament info
If you're using an official Bambu Lab spool, the AMS reads the filament type and color automatically via RFID. If you're using a third-party spool (including ALT TAB filament), you'll need to set the filament type manually on the printer screen or in Bambu Studio. Bambu Lab's AMS setup and filament loading guide covers both.
Unloading Filament from the AMS
1. Press "Unload" on the touchscreen
This retracts the filament from the extruder back into the AMS.
2. Release the feeder tab
Push the feeder tab forward by hand, then pull the filament out.
3. If the spool feels stuck
Gently push the spool toward the front of the AMS, then back again — this usually disengages the gear so you can wind the remaining filament back onto the spool by hand. Keep hold of the end as you rewind, or you risk a tangle later on.
Loading and Unloading via the Rear Spool Holder
This method is needed for filament types the AMS doesn't support, or if you're not using an AMS at all.
1. Unload any filament currently in the extruder
If the AMS is connected and filament is already loaded, unload it from the AMS screen first.
2. Feed filament through the rear bowden tube
Select load filament on the printer screen (the printer heats the nozzle for you), then feed the filament in by hand until the printer registers it and begins pulling it through.
3. Switch the AMS on or off as needed
On newer firmware, you can toggle "Enable AMS" when starting a print — leave it unchecked to print from the spool holder without disconnecting the AMS entirely.
For the complete, model-specific steps (they vary slightly between the X1C, P1S, and other Bambu Lab models), Bambu Lab's official loading guide walks through each printer's exact process.
Quick Recap
- AMS: insert spool → auto-detect or manually set filament info → unload via the screen when swapping
- Spool holder: unload any AMS filament first → heat nozzle → feed by hand → toggle "Enable AMS" as needed
- Third-party filament (like ALT TAB) needs manual filament info entry — RFID auto-detection only works with official Bambu Lab spools