ASR Multi-Wheel

Fully Automated Multi-Color (TPU) on the Bambu A-Series

The ASR Multi-Wheel is a 4-channel automated filament changer for Bambu A1, and A1 mini printers. It emulates a Bambu AMS Lite over the native BambuBus, so the printer drives it directly - load, print, unload, and re-load, fully unattended, with no slicer workarounds or manual intervention.

What makes it different is what it's built to run: flexible filament. Where an AMS Lite struggles with or refuses TPU and other materials, the Multi-Wheel handles it - including stiff and soft grades down to 95A - reliably enough to do genuine automated multi-color flexible prints.

That capability doesn't come from firmware alone. The Multi-Wheel pairs a purpose-tuned control system with real mechanical changes for flexibles:

  • Hardware built for TPU - gap elimination through the filament path, path tuning, and an extended Hall sensor arrangement for accurate tension sensing on soft, springy filament.

  • A ground-up controller - not a BMCU. It may look like a BMCU-style device, but it does not use the BMCU controller board. The Multi-Wheel runs a scratch-built ESP32 controller with entirely custom firmware, a web interface for adjusting settings, and an interactive on-device display.

  • Closed-loop feed control - encoder position tracking plus Hall-effect tension sensing for clean, repeatable loads and swaps.

  • Custom load/unload logic - a state machine tuned specifically for how flexible filament behaves in the PFTE tube.

  • Built to a similar form-factor as Bambu AMS Lite - Use all of your AMS Lite accessories like stock spool hubs, custom printed spool covers, or other ASR 5th Wheel accessories available on MakerWorld (Search ASR Fabs).

  • Based on the 5th Wheel Firmware - Starting with the 5th Wheel V7.6.3 Firmware, we edited and modified through 86 development versions over 10 weeks to the current V22.37 now running. This is currently a fined tuned fully functioning machine.

The Multi-Wheel exists to showcase the filament-handling technology behind the ASR 5th Wheel - the product we're bringing to Kickstarter.

Want in? Register at ASR5thWheel.com for advance notification of the ASR 5th Wheel Kickstarter.

And here's the deal: once we reach 350 registrations, the ASR Multi-Wheel becomes a fully open-source DIY project - printable part patterns, firmware, complete materials list, and build instructions, released free on MakerWorld. Sign up, spread the word, and help unlock it!