Bambulab P1S / X1C Air Return Duct Remix

Quick Description

This is a remix of larsvommars’ excellent Bambulab P1S / X1C Luftrückführung (V2).
My version closes the purge passage, turning it into a fully enclosed recirculation duct for better reliability. It attaches with seven magnets, installs in seconds, and should always be removed after the print is finished.
Requires 14× 10×3 mm magnets. STEP files included for easy customization.

Full Description

A big thank you to larsvommars, who kindly changed the licensing terms to allow this remix.

I found his original design brilliant, as it brings several improvements at once:

• Reduces the noise of the exhaust fan.
• Retains extracted warm air, lowering the workload of the active heating system (if present), or allowing for a higher chamber temperature when none is available.
• Converts the exhaust system into a true air scrubber, limiting the release of volatile substances into the environment.

The only issue I had with the original version was the occasional clogging of purge blobs between the back wall of the printer and the ventilation duct. This was especially common with carbon or glass-filled filaments, which tend to produce curly and loosely compacted purges.

To solve this, I modified the design into a fully enclosed recirculation duct by removing the purge passage door.
The duct is magnet-mounted (7 magnets) and can be installed or removed in seconds. In my setup, I usually leave it unmounted and only install it after the final purge. Just as with the original version, it is essential to remove it before starting a new print, especially multicolor jobs, to avoid problems.

Assembly notes:

• You will need 14 round magnets (10×3 mm).
• The slots might feel slightly loose, since I printed with Bambu ABS-GF, which shrinks a bit and reduces hole diameter. A strong cyanoacrylate glue ensures a firm hold.
• Magnet holes are 3.4 mm deep, so magnets don’t directly touch, preventing gaps and making separation easier while keeping the hold strong.
• To detach the duct from the base, there are small indentations on the right side for finger leverage.
• STEP files are included for anyone who wants to adjust tolerances, change magnet type, or make further modifications.
• I chose not to include a TPU gasket slot, since airflow naturally prefers larger openings and the back cover of my X1C is not perfectly flat, making a perfect seal unlikely. A thin adhesive window seal might work better if needed.

Attach the base to the frame using four flat-head self-tapping screws, 3x8 mm (ref. Bambu BT3x8-AA108).

For installation on the printer, also refer to the instructions in larsvommars’ original project.


For those interested, I have also designed a Purge Chute fully compatible with the magnetic base of the recirculator.
It can be mounted when the recirculator is not in use, ensuring purge blobs are properly collected and avoiding buildup.
You can find it here: Purge Chute for Air Recirculator (Mag Remix).