Most flexible filament work still means pausing a print and feeding a new spool by hand. ASR 5th Wheel takes a different route here: a fully automated swapping system for 85A TPU running on a Bambu Lab A1 Mini. Flexible materials are notoriously awkward to feed reliably, so seeing the changeovers happen without manual intervention is what makes this build worth a close look.
The heart of the setup is the ASR BMCU Helper. Bowden tubes run from overhead spools down to the toolhead, two spools of 85A TPU feed the system, and a small monochrome screen displays parameters while everything runs. The helper also carries clearly labelled ports: BYPASS, BMCU, ESP32 and DATA. It all looks compact enough to sit beside the printer without taking over a whole desk.
The print demonstrated is a spiked rosette that shifts from a black TPU base up to blue upper sections. The black Rel3D 85A TPU measures 1.75 mm and wants a nozzle between 190 and 230 degrees, while the blue TPU-85A prints at 210 to 230 degrees. Those ranges overlap, and in my view that overlap looks like room for a single shared temperature setting, though the maker has not said what was chosen. Elsewhere, the maker has worked with White PLA Basic and various 95A TPUs, and shared a 5-color TPU soccer ball remix model.
One open point: on that soccer ball remix, the maker noted the print does not bounce much without air pressure. It would be great to watch the automated system tackle a five-color run at that scale.
Project by ASR 5th Wheel. Watch it on their YouTube channel: