Bowden Extruder

thingiverse

This is a relatively simple bowden extruder, designed specifically for a particular mounting scenario. I couldn't find an off-the-shelf solution that fit my needs, so I created this one from scratch. My 3D printer sits in an Ikea Stuva box with a glass door, which houses several of my filament dispenser boxes. The filament is fed through the top into a direct drive extruder, working well but I wanted to try a bowden extruder for experience's sake. This extruder is tailored to fit on top of the housing, as shown in the images. Update: I added a bowden extruder body compatible with the original Prusa i3 MK2/S. It's basically the original part with the motor mount trimmed away and an extra hex nut added for secure top mounting. I also removed the second hex nut that was mistakenly included. Since the extruder uses a different drive gear, I had to recalibrate the steps/mm for the extruder motor using the M503, M92, and M500 commands. You can find detailed documentation on the Marlin website. For the Prusa i3, I adjusted the extrusion from 161.3 steps/mm to 142.1 steps/mm. I also modified the retraction settings in Slic3r to a 5 mm retraction length and 100 mm/s retraction speed. This is just a starting point and will likely be refined later on. The first print shown in the images surprised me by working well right out of the box, but it still needs fine-tuning as there's some over-extrusion and bed height offset issues. I noticed that the extruder motor skips steps under high load situations, which might be due to the current settings. I'll probably switch to the original Prusa motor. Other than that, it works surprisingly well. ChangeLog: * 2018-03-10: Original Prusa motor and drive gear mounted. No more stalls or skipped steps, working fine. Fine-tuning of Slic3r can begin... * 2018-03-03: Extruder assembled and tested. * 2018-03-02: Original upload Parts list: The extruder uses the following parts: * 1 E3D Hobb-Goblin 5mm drive gear * 1 E3D groove mount bowden adaptor * 1 quick connector for Teflon tube * 1 push fit M5 thread * 1 625 ball bearing * 1 5x14 mm cylinder rod * 2 M6x40 screws * 5 M3x35 screws * 1 M3x40 screw (+ spring and washers) * 2 hex nuts M6 * 1 hex nut M3 * 1 square nut M3