AMS Not Loading
Bambu Lab 3D Printer
Severity:What Does This Error Mean?
The Bambu Lab AMS failing to load filament is usually caused by a loose PTFE tube connection between the AMS and the printer, a filament tangle on the spool, or moisture-damaged filament that has become brittle and snapped inside the buffer. Check all PTFE tube connections and inspect the AMS hub for stuck filament.
Affected Models
- Bambu Lab X1C with AMS
- Bambu Lab X1E with AMS
- Bambu Lab P1S with AMS
- Bambu Lab P1P with AMS
Common Causes
- PTFE tube connection is loose or not fully inserted into the AMS or hub
- Filament has snapped inside the AMS buffer or PTFE tube
- Moisture-absorbed filament is brittle and breaking during the loading cycle
- Spool is tangled and cannot unwind freely
How to Fix It
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Check all PTFE tube connections — at the AMS slot exit, at the AMS hub, and at the printer toolhead entry. Each connection should click firmly into the coupler. Push in firmly then try to pull out — it should not move.
The most common cause of AMS loading failure is a PTFE tube that has backed out of a coupler by a few millimetres. A small gap allows filament to miss the tube and jam.
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Open the AMS lid and check the spool for tangles. Manually pull a short length of filament from the spool and feed it into the AMS slot by hand to confirm it moves freely.
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Inspect the AMS buffer and hub for broken filament. A stub of filament stuck in the hub will block the next load attempt. Use the filament eject function from the touchscreen to push any stuck piece out.
Access the AMS buffer by opening the transparent cover on the right side of the AMS unit. Broken stubs can be pushed through using a piece of the same filament as a pusher.
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If filament breaks repeatedly during loading, dry the spool. Moisture-damaged filament is brittle and snaps under the feeding force. Dry at 65°C for 4–6 hours in a food dehydrator.
Frequently Asked Questions
Can I use the Bambu Lab printer without the AMS?
Yes — all Bambu Lab printers that support AMS can also print from an external spool using the external filament path. Feed the filament directly into the extruder entry port on top of the printer, bypassing the AMS entirely. This is useful when the AMS needs maintenance or when printing with a filament type the AMS does not handle well.