B2D modified 1.75 bowden exit (stronger)

thingiverse

I've been using the original B2D extruder for several months now, and it has completely revolutionized my bargain basement Tronxy X3. Thanks to the designer who created this fantastic component. However, during a recent print job that involved multiple retractions of the Veronoi model, the bowden output support failed (see photo). This may have been due to printing the part upside down without supports or rafting. As a result, the layers' grain was not optimized for strength. When extruder pressure is high, this component can withstand significant force. Luckily, I had created a few spares, which allowed me to replace the broken part in mid-print and resume the job without any issues. From the start, I noticed that the part would bend slightly under heavy pressure loads and retractions. So, it's likely that failure was inevitable. The entire extruder is made of PLA. To prevent future failures, I decided to make a small modification to the component. I increased the thickness of the external bowden support plate by 50% (adding about 2mm more, which brought it from 4mm to 6mm). Additionally, I added some sheet metal under the M3 retaining screw head to distribute the load better. This required using a slightly longer than standard M3 screw with this modification. The result is a significantly stronger component that I doubt will fail again. The rest of the extruder has been incredibly reliable and sturdy. I'm confident it will outlast me. The new part is clearly visible in red PLA on an otherwise all-white extruder. P.S. I also increased the filament pass-through hole to 4mm, which allows for the use of a metal PTFE tube retainer that enables the PTFE to pass through almost touching the drive pinch rollers. This makes inserting filament easier and reduces friction in the pathway.