How Can I Switch to the Next Spool in the Menu?

With the rise of multi-material stations like the Bambu Lab AMS, Prusa MMU3, and the Anycubic ACE Pro, managing multiple filament spools from a single menu has become a core skill for 3D printing hobbyists. Whether you are performing a manual color change or setting up "Filament Backup" (auto-refill), navigating the spool menu correctly is essential to prevent print failures. Here is how to switch spools across the most popular 3D printing ecosystems.

1. Bambu Lab AMS (X1C, P1S, and A1 Series)

Bambu Lab printers handle spool switching through the "Device" tab on the screen or within the Bambu Handy app.

• To switch manually: Navigate to the External Filament or AMS menu on the touch screen. Tap on the slot (1, 2, 3, or 4) you wish to use. Select "Load" to pull that specific spool into the toolhead.
• To enable Auto-Switch (Filament Backup): Ensure two slots have the exact same Filament Type (e.g., PLA) and Color. In the AMS settings menu, toggle "AMS Filament Backup" to ON. The printer will now automatically switch to the next spool when the first one runs out.

2. Prusa Research (MMU2S / MMU3)

Prusa’s Multi-Material Upgrade (MMU) uses a more linear menu system via the original LCD or the newer MK4 touch interface.

1. Go to the Main Menu on your Prusa.
2. Select Load Filament.
3. The menu will prompt you to choose Filament 1 through 5.
4. Select the number corresponding to the spool you want to use. The selector will slide to that position, and the pulleys will drive the filament to the extruder.

3. Creality K1 / Ender Series (Filament Sensor Logic)

For printers without an automated changer, "switching to the next spool" usually refers to the M600 command or a manual pause.

• During a Print: Navigate to the Pause menu. Select Unload. Once the old spool is removed, place the new spool on the holder, feed it into the sensor, and select Load in the menu.
• KFS (Klipper Filament Sensor): If your printer uses Klipper, you can switch spools in the Mainsail/Fluidd web interface by clicking the "Extrude" macro after swapping the physical roll.

Comparison of Multi-Spool Management Systems

Understanding the hardware capabilities of your menu system helps in planning long-distance or multi-color prints.

4. Troubleshooting Menu "Ghosting"

Sometimes the menu shows a spool is loaded, but it isn't, or it refuses to switch to the next slot.

• The Fix: Check the Filament Hub or Buffer. If a piece of the previous filament snapped off inside the tube, the menu will "lock" that slot and prevent you from switching to the next spool until the sensor is cleared.
• RFID Conflicts: If using Bambu spools, the RFID tag might override your manual menu selection. You may need to manually edit the filament type in the menu if the printer misidentifies the next spool.

5. Switching Spools via Slicer (G-Code)

The most efficient way to switch spools isn't in the printer menu, but in the Slicer (Cura, PrusaSlicer, OrcaSlicer).

1. Assign different colors/slots to different parts of your model in the slicer.
2. The G-code will contain a T0, T1, or T2 command.
3. When the printer reads this, it will automatically perform the "switch to next spool" logic without you needing to touch the physical menu.

Conclusion

Switching to the next spool in the menu is a matter of navigating to your printer's Filament or Material Management tab. For automated systems like the AMS or MMU, ensure your filament profiles (type and color) match in the menu to enable seamless transitions. For manual printers, the "Next Spool" switch is a coordinated dance between the Pause command and the Load/Unload menu functions. Master these menus, and you can print larger-than-spool objects with zero downtime.