Bowden Extruder for Flexible TPE/TPU Filaments

thingiverse

After battling to print TPE filament on my Kossel Mini delta printer (nowden extruder) for far too long, I decided to take a step back and rethink my entire approach by designing an all-new extruder that incorporates every feature necessary to successfully print this incredibly flexible material. The primary objective of the design is to position the "exit hole" as close as feasible to the feed gear in order to eliminate any possibility of it kinking and jamming. The other key design consideration was ensuring that both the entry and exit holes are perfectly aligned with the edge of the drive gear, which helps minimize physical resistance to an absolute minimum. As a bowden extruder, this reduced friction also significantly enhances its performance when working with extremely rigid filaments such as PLA. Through extensive trial and error, I've come to realize that not only must the speed be kept at a very low setting (I discovered that 10mm/sec was completely trouble-free), but it's equally crucial to keep the pressure on the idler bearing as light as possible so as not to damage or distort the filament in any way as it passes through.